Chiral platinum duphos terminal phosphido complexes: Synthesis, structure, phosphido transfer, and ligand behavior

Article abstract of DOI:10.1021/om060614y

Treatment of Pt halide precursors with the secondary phosphine PHMe(Is) in the presence of the base NaOSiMe₃ gave the terminal phosphido complexes Pt(Duphos)(Ph)(PMeIs) (Is = 2,4,6-(i-Pr)₃C ₆H₂, Duphos = (R,R)-Me-Duphos (1), (R,R)-i-Pr-Duphos (2)), Pt((R,R)-Me-Duphos)(X)(PMeIs) (X = I (3), Cl (4)), and Pt((R,R)-Me-Duphos) (PMeIs)₂ (5). Low-barrier pyramidal inversion in the phosphido complexes was investigated by ³¹P NMR spectroscopy. Protonation of 1-5 with HBF₄ gave the secondary phosphine complexes [Pt(Duphos)(Ph)(PHMeIs)][BF₄] (Duphos = (R,R)-Me-Duphos (6), (R,R)-i-Pr-Duphos) (7)), [Pt((R,R)-Me-Duphos)(X)(PHMeIs)][BF₄] (X = I (8), Cl (9)), and [Pt((fl,/?)-Me-Duphos)(PHMeIs)₂][BF ₄]₂ (10); cations 6, 9, and 10 were prepared independently from Pt chloride precursors using Ag(I) salts and PHMe(Is) and then deprotonated to yield phosphido complexes 1-5. Oxidation of the phosphido ligands in 4 and 5 with H₂O₂ gave Pt((R,R)-Me-Duphos)(Cl) (P(O)MeIs) (11) and Pt((R,R)-Me-Duphos)(P(O)-MeIs)₂ (12), respectively. Complexes 1-6, 9, and 11 were structurally characterized by X-ray crystallography; structural and ³¹P NMR results suggest the trans influence order P(O)MeIs > PMeIs > PHMe(Is). Reaction of 1 with [Pd(allyl)Cl]₂, followed by treatment with dppe, gave Pt((R,R)-Me-Duphos)-(Ph)(Cl), PMeIs(allyl) (13), and Pd(dppe)₂. Treatment of 1 with Pd(P(o-Tol)₃)₂ gave an equilibrium mixture containing the two-coordinate palladium complex Pd(P(o-Tol) ₃)(μ-PMeIs)Pt((R,R)-Me-Duphos)(Ph) (14), Pd(P(o-Tol) ₃)₂, P(o-Tol)₃, and 1.

Full text of DOI:10.1021/om060614y

Organometallics 2006, 25, 5435-5448
5435
Chiral Platinum Duphos Terminal Phosphido Complexes: Synthesis,
Structure, Phosphido Transfer, and Ligand Behavior
Corina Scriban,† David S. Glueck,*,† Antonio G. DiPasquale,‡ and Arnold L. Rheingold‡
6128 Burke Laboratory, Department of Chemistry, Dartmouth College, HanoVer, New Hampshire 03755,
and Department of Chemistry and Biochemistry, UniVersity of California, San Diego, 9500 Gilman DriVe,
La Jolla, California 92093
ReceiVed July 7, 2006
Treatment of Pt halide precursors with the secondary phosphine PHMe(Is) in the presence of the base
NaOSiMe3 gave the terminal phosphido complexes Pt(Duphos)(Ph)(PMeIs) (Is ) 2,4,6-(i-Pr)3C6H2, Duphos
) (R,R)-Me-Duphos (1), (R,R)-i-Pr-Duphos (2)), Pt((R,R)-Me-Duphos)(X)(PMeIs) (X ) I (3), Cl (4)),
and Pt((R,R)-Me-Duphos)(PMeIs)2 (5). Low-barrier pyramidal inversion in the phosphido complexes
was investigated by 31P NMR spectroscopy. Protonation of 1-5 with HBF4 gave the secondary phosphine
complexes [Pt(Duphos)(Ph)(PHMeIs)][BF4] (Duphos ) (R,R)-Me-Duphos (6), (R,R)-i-Pr-Duphos) (7)),
[Pt((R,R)-Me-Duphos)(X)(PHMeIs)][BF4] (X ) I (8), Cl (9)), and [Pt((R,R)-Me-Duphos)(PHMeIs)2][BF4]2
(10); cations 6, 9, and 10 were prepared independently from Pt chloride precursors using Ag(I) salts and
PHMe(Is) and then deprotonated to yield phosphido complexes 1-5. Oxidation of the phosphido ligands
in 4 and 5 with H2O2 gave Pt((R,R)-Me-Duphos)(Cl)(P(O)MeIs) (11) and Pt((R,R)-Me-Duphos)(P(O)-
MeIs)2 (12), respectively. Complexes 1-6, 9, and 11 were structurally characterized by X-ray
crystallography; structural and 31P NMR results suggest the trans influence order P(O)MeIs > PMeIs >
PHMe(Is). Reaction of 1 with [Pd(allyl)Cl]2, followed by treatment with dppe, gave Pt((R,R)-Me-Duphos)-
(Ph)(Cl), PMeIs(allyl) (13), and Pd(dppe)2. Treatment of 1 with Pd(P(o-Tol)3)2 gave an equilibrium mixture
containing the two-coordinate palladium complex Pd(P(o-Tol)3)(µ-PMeIs)Pt((R,R)-Me-Duphos)(Ph) (14),
Pd(P(o-Tol)3)2, P(o-Tol)3, and 1.
Scheme 1. Diastereoselective Complexation by
P-Stereogenic Metallophosphinesa
Introduction
Terminal metal phosphido complexes (M-PR2) contain
nucleophilic phosphorus centers which can act as ligands to other
metals; these “metallophosphines” form the bimetallic com-
plexes M-PR2-M′. The metal substituent M may result in
cooperative reactivity1 or simply modify the properties of the
phosphine.2 For example, chiral-at-Re complexes such as Re-
(η5-C5H4PPh2)(PPh3)(NO)(PPh2) have been used in asymmetric
catalysis.3 Another class of chiral metallophosphines is phos-
phorus-stereogenic, as in A and B (Scheme 1),4 which contain
an additional chiral group (the diphosphine in A and the Ta in
B). Because of the low barrier to pyramidal inversion at P in
metallophosphines,5 these compounds are expected to exist as
mixtures of rapidly interconverting diastereomers. Thus, the Fe-
phosphido complex A was a 4:1 mixture of diastereomers at
-65 °C, but only one diastereomer of B was observed by NMR
spectroscopy.4
a dr ) diastereomer ratio.
A thermodynamic preference for one diastereomer (as seen
for B) and/or a kinetic difference in the rates of complexation
of such ligands to a second metal might result in “self-resolving”
P-stereogenic metallophosphines and their metal complexes,
which could be useful in asymmetric catalysis. For example,
reaction of B with Cr(CO)5(THF) gave a single diastereomer
of the Ta-Cr product (without, however, absolute stereocontrol
at Ta or P). A similar reaction of A gave a 3:2 mixture of
diastereomers, which were separated by crystallization.4
To investigate the rational design and application of such
P-stereogenic metallophosphines, we report here the preparation,
structure, and reactivity of a class of chiral Pt(Duphos) terminal
phosphido complexes (Chart 1). As in the Fe complex A, a chiral
diphosphine was intended to provide thermodynamic control
* To whom correspondence should be addressed. E-mail: glueck@
dartmouth.edu
† Dartmouth College.
‡ University of California, San Diego.
(1) (a) Stephan, D. W. Coord. Chem. ReV. 1989, 95, 41-107. (b) Baker,
R. T.; Fultz, W. C.; Marder, T. B.; Williams, I. D. Organometallics 1990,
9, 2357-2367.
(2) For a recent example, see: Giner Planas, J.; Gladysz, J. A. Inorg.
Chem. 2002, 41, 6947-6949.
(3) (a) Delacroix, O.; Gladysz, J. A. Chem. Commun. 2003, 665-675.
(b) Zwick, B. D.; Arif, A. M.; Patton, A. T.; Gladysz, J. A. Angew. Chem.,
Int. Ed. 1987, 26, 910-912.
(4) For A, see: Hey, E.; Willis, A. C.; Wild, S. B. Z. Naturforsch., B
1989, 44, 1041-1046. For B, see: Challet, S.; Lavastre, O.; Moise, C.;
Leblanc, J.-C.; Nuber, B. New J. Chem. 1994, 18, 1155-1161.
(5) Rogers, J. R.; Wagner, T. P. S.; Marynick, D. S. Inorg. Chem. 1994,
33, 3104-3110.
10.1021/om060614y CCC: $33.50 © 2006 American Chemical Society
Publication on Web 09/19/2006

5436 Organometallics, Vol. 25, No. 22, 2006
Scriban et al.
Chart 1. Pt(Duphos) Terminal Phosphido Complexes as
P-Stereogenic Metallophosphinesa
Scheme 3a
a X ) Ph, R ) Me (1), R ) i-Pr (2); X ) I (3), Cl (4), R ) Me; X
) PMe(Is), R ) Me (5).
Scheme 2a
a [Pt] ) Pt((R,R)-Me-Duphos).
(5), respectively.10 In contrast to the syntheses of 1-3, however,
it was difficult to control the stoichiometry of these reactions
and obtain 4 free of 5, or vice versa. Moreover, other phosphido
complexes tentatively formulated as Pt((R,R)-Me-Duphos)-
(OSiMe3)(PMeIs) and Pt((R,R)-Me-Duphos)(OH)(PMeIs), as
well as other unidentified impurities, were formed; see the
Experimental Section for details.
Therefore, complexes 4 and 5 were also prepared by the
multistep route shown in Scheme 3. Abstraction of chloride
using Ag(I) salts, followed by treatment with PHMe(Is), gave
the cationic secondary phosphine complexes 6, 9, and 10, whose
properties are described in more detail below. Deprotonation
then gave phosphido complexes 1, 4, and 5. Although this
method also failed to provide pure 4 and 5, they were
characterized by spectroscopy and by X-ray crystallography (see
below) and could be used to prepare derivatives.
The phosphido complexes 1-5 are yellow-to-orange crystal-
line solids. Their high air sensitivity made it very difficult to
obtain satisfactory elemental analyses;11 as described in the
Experimental Section, analyses were often consistent with
oxidation at the phosphido P. Indeed, deliberate oxidation of 4
and 5 gave Pt((R,R)-Me-Duphos)(Cl)(P(O)MeIs) (11) and Pt-
((R,R)-Me-Duphos)(P(O)MeIs)2 (12), which are described be-
low. However, protonation at P gave the cationic secondary
phosphine complexes 6-10 (see Scheme 3 and below), which
could be isolated in analytically pure form.12
Phosphido complexes 1-5 were characterized by multinuclear
NMR spectroscopy; 31P NMR data appear in Table 1. As
previously observed for terminal Pt-phosphido complexes, the
PMeIs group displayed characteristic trans JPP and JPt-P values,
which are smaller than those for tertiary phosphine ligands.13
Because of peak overlap in the Duphos region, these species
were most conveniently characterized by their PMeIs shifts.
Low-temperature 31P NMR spectroscopy showed the expected
two diastereomers for 3 and 4 and three of the four diastereomers
for 5, but the results were more complicated for 1 and 2 (four
diastereomers each). We believe the “extra” resonances within
a [Pt] ) Pt((R,R)-Me-Duphos) for 1 and 3-5; [Pt] ) Pt((R,R)-i-Pr-
Duphos) for 2.
of the phosphido stereocenter, via Duphos-phosphido interac-
tions. However, to provide greater steric differentiation of the
P substituents, the P-Ph group was replaced by the bulky aryl
2,4,6-(i-Pr)3C6H2 (isityl ) Is).6 To investigate substituent effects
on the diastereomer ratio (dr) in this class of metallophosphines,
the chiral ancillary ligand and the Pt-X substituent were also
varied.7
Results and Discussion
Synthesis and Structure of Pt(Duphos) Terminal Phos-
phido Complexes Treatment of Pt((R,R)-Me-Duphos)(Ph)(Cl)8
or the i-Pr-Duphos analogue (see the Experimental Section) with
the secondary phosphine PHMe(Is)9 and the base NaOSiMe3
gave the terminal phosphido complexes Pt(Duphos)(Ph)(PMeIs)
(Duphos ) (R,R)-Me-Duphos (1), (R,R)-i-Pr-Duphos (2)) in high
yield. An analogous reaction of Pt((R,R)-Me-Duphos)I2 gave
the iodo phosphido complex Pt((R,R)-Me-Duphos)(I)(PMeIs)
(3), even when an excess of PHMe(Is) and base was used
(Scheme 2).8
Similarly, treatment of Pt((R,R)-Me-Duphos)Cl2 with 1 or 2
equiv of the secondary phosphine and NaOSiMe3 gave Pt((R,R)-
Me-Duphos)(Cl)(PMeIs) (4) and Pt((R,R)-Me-Duphos)(PMeIs)2
(6) We showed earlier that Pd((R,R)-Me-Duphos)(Ph)(PMeIs) was a ca.
40:1 mixture of diastereomers at -60 °C (Moncarz, J. R.; Laritcheva, N.
F.; Glueck, D. S. J. Am. Chem. Soc. 2002, 124, 13356-13357). These
complexes decompose by P-C reductive elimination at room temperature,
but the Pt analogues reported here are thermally stable.
(7) For the use of the phosphido complexes as catalyst precursors in
asymmetric alkylation of PHMe(Is), see: (a) Scriban, C.; Glueck, D. S. J.
Am. Chem. Soc. 2006, 128, 2788-2789. For the related use of chiral cationic
Pt-bis(phosphine) moieties for the selective binding of chiral phosphines
or amines, see: (b) Payne, N. C.; Stephan, D. W. J. Organomet. Chem.
1981, 221, 223-230. (c) Payne, N. C.; Stephan, D. W. J. Organomet. Chem.
1982, 228, 203-215.
(8) Brunker, T. J.; Blank, N. F.; Moncarz, J. R.; Scriban, C.; Anderson,
B. J.; Glueck, D. S.; Zakharov, L. N.; Golen, J. A.; Sommer, R. D.; Incarvito,
C. D.; Rheingold, A. L. Organometallics 2005, 24, 2730-2746.
(9) Brauer, D. J.; Bitterer, F.; Dorrenbach, F.; Hessler, G.; Stelzer, O.;
Kruger, C.; Lutz, F. Z. Naturforsch., B 1996, 51, 1183-1196.
(10) Wicht, D. K.; Zhuravel, M. A.; Gregush, R. V.; Glueck, D. S.; Guzei,
I. A.; Liable-Sands, L. M.; Rheingold, A. L. Organometallics 1998, 17,
1412-1419.
(11) This phenomenon has been observed for related electron-rich
terminal phosphido complexes which could also not be isolated in
analytically pure form; see: Giner Planas, J.; Hampel, F.; Gladysz, J. A.
Chem. Eur. J. 2005, 11, 1402-1416.
(12) For protonation of air-sensitive tertiary phosphines to yield air-stable
phosphonium salts, see: Netherton, M. R.; Fu, G. C. Org. Lett. 2001, 3,
4295-4298.
(13) Zhuravel, M. A.; Glueck, D. S.; Zakharov, L. N.; Rheingold, A. L.
Organometallics 2002, 21, 3208-3214 and references therein.

Pt Duphos Terminal Phosphido Complexes
Organometallics, Vol. 25, No. 22, 2006 5437
Table 1. Low-Temperature 31P{1H} NMR Data for the Phosphido Complexesa
complex
T (°C)
-75
δ(P1) (JPt-P
)
δ(P2) (JPt-P
)
δ(P3) (JPt-P
)
J12
J13
J23
drb
98
2.2
1.2
1
Pt(Me-Duphos)(Ph)(PMeIs) (1a)c
56.5 (1653)
57.3 (1868)
-55.9 (889)
136
136
142
134
129
129
139
140
113
110
124
126
84
1b
1c
1d
-47.3 (∼940)
-49.5
-51.6
Pt(i-Pr-Duphos)(Ph)(PMeIs) (2a)c
-60
54.6 (1683)
48.2 (1838)
-67.1 (903)
-58.5 (875)
-45.1 (951)
-48.0 (877)
-69.6 (820)
-42.5 (935)
-56.3 (804)
-37.2 (900)d
-62.9 (887)
-48.3 (1001)
-64.5 (929)
4
6
152
2b
2c
2d
1
24
23
8
1
23
1
13
13
1
56.1 (1704)
55.1 (1668)
64.0 (1575)
65.8 (1633)
69.3 (1607)
72.2 (1668)
66.2 (1679)
52.1 (1859)
60.6 (1597)
55.4 (1782)
53.8 (1827)
54.1 (3954)
65.0 (3876)
53.5 (4006)
Pt(Me-Duphos)(I)(PMeIs) (3a)
-40
-20
-50
21
13
17
3b
Pt(Me-Duphos)(Cl)(PMeIs) (4a)
13
11
4b
58.1 (3978)d
Pt(Me-Duphos)(PMeIs)2 (5a)
11
12
13
5b
5c
109
98
11
7
a All Duphos ligands have the R,R configuration. Chemical shifts are given in ppm (85% H3PO4 external standard) and coupling constants in Hz. The
solvent was THF-d8. For atom labeling, see the figure above. In several cases (especially for minor diastereomers), it was not possible to assign Duphos P
resonances; therefore, they are omitted. b dr ) diastereomer ratio, from integration of the 31P NMR spectra at -50 °C. c In addition to the expected diastereomers,
which differ in configuration at P3, more diastereomers were observed for complexes 1 and 2. The “extra” ones are assigned as rotamers (see the text for
discussion). d Broad peaks.
each group of signals are due to conformational isomers, perhaps
resulting from slow rotation about the P-C(Is) bond, as
observed in low-temperature spectra of the analogous complexes
Pt(dppe)(C(O)C3F7)(PPhAr) (Ar ) o-MeOC6H4, Is, Mes, Mes-
F9; Mes ) 2,4,6-Me3C6H2; Mes-F9 ) 2,4,6-(CF3)3C6H2).14
The effect of substituents on the thermodynamics of the
diastereomers with different configurations at the phosphido
stereocenter was assessed by measuring diastereomer ratios of
1-5 at -50 °C (Table 1). The Me-Duphos complex 1 was a
98:1:1.2:2.2 mixture of isomers, which displayed similar PMeIs
31P NMR chemical shifts. Assuming that the three minor isomers
all have the same configuration at P means this is a 22:1 ratio
of diastereomers whose main difference is the P stereochemistry,
while the ratio might be larger if one or more of the minor peaks
are due to a rotamer of the major diastereomer. For the i-Pr-
Duphos complex 2, a 152:1:24:23 mixture was observed. In
this case, the two groups of distinctly different PMeIs chemical
shifts suggest that the major diastereomer is a 152:1 mixture of
rotamers, while the minor diastereomer is a ∼1:1 mixture of
rotamers. With this assumption, the ratio of “invertomers” is
about 3:1. Thus, the more sterically demanding i-Pr-Duphos
ligand provided reduced stereocontrol.
(Table 2). The spectra of halide complexes 3 and 4 were the
simplest, since only two diastereomers were observed at low
temperature; their signals coalesced on warming. Measurement
of the coalescence temperatures for the three different P nuclei
provided approximate free energies of activation for the dynamic
process,16 which is presumably a composite of P inversion and
rotation about the Pt-P bond.14 Analysis of the coalescence
behavior of the two major sets of signals for the bis(phosphido)
complex 5 yielded a barrier similar in magnitude, but we cannot
tell if this involves one or two P inversions, since the absolute
configuration at the phosphido stereocenters is not known. For
the i-Pr-Duphos complex 2, coalescence of the signals due to
the “invertomers” occurred before that of the rotamers; thus, it
was possible to obtain approximate barriers to both processes,
which are similar in magnitude. The low intensities of the peaks
due to the minor diastereomers of 1 prevented similar measure-
ments in this case.
As in related Pt-phosphido complexes, the inversion/rotation
barriers for 2-5 were low, about 10-12 kcal/mol (Table 2).13-15
A similar barrier was observed for Pt((R,R)-Me-Duphos)(Me)-
(PPh(i-Bu)),15c which suggests that the bulky isityl group did
not have a large effect.
Similarly, comparison of diastereomer ratios for the Me-
Duphos complexes 3 and 4 showed that the smaller chloro group
(23:1) gave a higher dr value than did an iodo ligand (8:1).
Finally, three of the potential four diastereomers of the bis-
(phosphido) complex 5 were observed; two were thermody-
namically preferred at low temperature (ca. 13:13:1). As
expected, the diastereomer preference in complexes 1-5 was
more pronounced than in the related Pt((R,R)-Me-Duphos)(Me)-
(PPh(i-Bu)), which contains P substituents of similar size (dr
) 1.4:1, -40 °C, toluene-d8).15c
The phosphido complexes 1-5 were also characterized
by X-ray crystallography (Figures 1-5, Tables 3 and 4, and
Supporting Information). Although two (or more) diastereo-
mers of each complex were observed by NMR spectroscopy
in solution, only one was observed in these single-crystal
structures. Moreover, the (RP)-PMeIs absolute configuration
was observed in complexes 1, 3, and 4 and for both phosphido
groups of 5. The latter observation means that 5 has approxi-
mate C2 symmetry (Figure S1, Supporting Information). The
(SP)-PMeIs group in 2 is consistent with this trend, since, de-
spite their identical R,R labels, (R,R)-Me-Duphos and (R,R)-
i-Pr-Duphos have opposite absolute configurations because
of the priority sequence rule definitions.17 These observations
could be explained if this class of (R,R)-Me-Duphos/(RP)-
PMeIs or (R,R)-i-Pr-Duphos/(SP)-PMeIs diastereomers were
Coalescence behavior involving both types of diastereomers
was observed by variable-temperature 31P NMR spectroscopy
(14) Wicht, D. K.; Glueck, D. S.; Liable-Sands, L. M.; Rheingold, A.
L. Organometallics 1999, 18, 5130-5140.
(15) (a) Wicht, D. K.; Kovacik, I.; Glueck, D. S.; Liable-Sands, L. M.;
Incarvito, C. D.; Rheingold, A. L. Organometallics 1999, 18, 5141-5151.
(b) Kovacik, I.; Wicht, D. K.; Grewal, N. S.; Glueck, D. S.; Incarvito, C.
D.; Guzei, I. A.; Rheingold, A. L. Organometallics 2000, 19, 950-953.
(c) Scriban, C.; Wicht, D. K.; Glueck, D. S.; Zakharov, L. N.; Golen, J. A.;
Rheingold, A. L. Organometallics 2006, 25, 3370-3378.
(16) Friebolin, H. In Basic One- and Two-Dimensional NMR Spectros-
copy, 2nd ed.; VCH: New York, 1993; pp 287-314.
(17) Burk, M. J.; Feaster, J. E.; Nugent, W. A.; Harlow, R. L. J. Am.
Chem. Soc. 1993, 115, 10125-10138.

5438 Organometallics, Vol. 25, No. 22, 2006
Table 2. Variable-Temperature 31P NMR Data (THF-d8) for Pt(Duphos) Phosphido Complexesa
Scriban et al.
complex
resonanceb
δ (ppm)
∆ν (Hz)
Tc (K)
∆Gcq (kcal/mol)
Pt(i-Pr-Duphos)(Ph)(PMeIs) (2a,b/2c,d)c
P1
P3
P1
P2
P3
P1
P2
P3
P1
P2
P1/P2
P3/P4
P1
55.2, 54.1
-42.9, -65.3
56.1, 55.1
55.4, 53.8
-45.1, -48.0
64.0, 65.8
54.1, 65.0
-69.6, -42.5
69.3, 72.2
53.5, 58.1
66.2, 52.1
-48.3, -62.9
69.6, 67.8
223
4452
202
324
587
263
288
243
243
243
263
243
283
283
283
288
288
283
313
12.1
11.6
11.2
11.0
10.7
11.8
10.0
11.3
12.5
12.3
11.8
11.8
12.8
13.4
Pt(i-Pr-Duphos)(Ph)(PMeIs) (2c,d)d
Pt(Me-Duphos)(I)(PMeIs) (3)
364
2206
5484
587
Pt(Me-Duphos)(Cl)(PMeIs) (4)
Pt(Me-Duphos)(PMeIs)2 (5)
Pt(Me-Duphos)(Me)(PPh(i-Bu))e
931
2853
2914
809
P3
-57.3, -63.9
1350
a All Duphos ligands have the R,R configuration. The solvent was THF-d8. Chemical shifts and ∆ν values are taken from slow-exchange spectra at -20
°C for invertomers 2a,b/2c,d, -60 °C for rotamers 2c/2d, -40 °C for 3, -20 °C for 4, and -40 °C for 5. Estimated errors are different for each resonance;
q
“typical” errors are 5 Hz in ∆ν, 10 °C in Tc, and 0.5 kcal/mol in ∆Gc . b See Table 1 for the P labeling scheme. c Interconversion of “invertomers”, which
are assumed, on the basis of the large difference in P3 chemical shifts, to have different configurations at the phosphido P. d Interconversion between
rotamers, which are assumed to have the same configurations at the phosphido P. e Reference 15c.
Figure 3. ORTEP diagram of one of the two independent
molecules of Pt((R,R)-Me-Duphos)(I)(PMeIs) (3).
Figure 1. ORTEP diagram of Pt((R,R)-Me-Duphos)(Ph)(PMeIs)
(1).
Figure 2. ORTEP diagram of one of the two independent
molecules of Pt((R,R)-i-Pr-Duphos)(Ph)(PMeIs) (2).
Figure 4. ORTEP diagram of Pt((R,R)-Me-Duphos)(Cl)(PMeIs)‚
C6D6 (4). Hydrogen atoms and the solvent molecule are omitted.
favored in the crystallization process and/or if the crystals chosen
for structure determination were not representative of the bulk
sample.
(PPh(i-Bu)) (D)15c is difficult, since the Pt-X group was also
varied, those in 1-5 are similar, suggesting that the bulky isityl
(Is) group does not constrain the Pt-phosphido bond length.
Indeed, the shortest Pt-PR2 bond in the series was observed
for C, with the bulkiest phosphido ligand, perhaps because of
the small size of the hydride ligand.
Similarly, the Pt-P1 (trans to PMeIs) bond was slightly
longer in 3 and 5 (2.2962(18) and 2.3063(10) Å, respectively)
than in 1 (2.2849(14) Å), consistent with the steric effects
described above; the iodo and phosphido ligands in 3 and 5
appear to be more sterically demanding than Cl in 4, for which
the Pt-P1 distance was 2.2851(15) Å. The Pt-P2 (trans to X)
Although i-Pr-Duphos is significantly more bulky than Me-
Duphos, only small differences were observed in the structures
of 1 and 2. Varying the other ancillary ligand (the Pt-X group)
led to larger structural changes. The Pt-PMeIs bond lengthened
from 2.3761(13) Å in the Pt-Ph complex 1 to 2.3926(16) Å in
the chloro complex 4, 2.3996(19) Å in the iodo complex 3, and
2.4117(10) and 2.3859(10) Å in the bis(phosphido) complex 5,
consistent with greater steric crowding in these cases. Although
direct comparison to the Pt-phosphido bond lengths in Pt((R,R)-
Me-Duphos)(H)(PPhIs) (C)15b and Pt((R,R)-Me-Duphos)(Me)-

Pt Duphos Terminal Phosphido Complexes
Organometallics, Vol. 25, No. 22, 2006 5439
Table 3. Crystallographic Data for the Complexes Pt((R,R)-Me-Duphos)(X)(PMeIs) (X ) Ph (1), Cl (3), I (4‚C6D6), PMeIs (5)),
Pt((R,R)-i-Pr-Duphos)(Ph)(PMeIs) (2), [Pt((R,R)-Me-Duphos)(X)(PHMeIs)][BF4] (X ) Ph (6‚CH2Cl2), Cl (9‚CH2Cl2)), and
Pt((R,R)-Me-Duphos)(Cl)(P(O)MeIs) (11‚0.5C7H8)a
1
2
3
4‚C6D6
5
6‚CH2Cl2
9‚CH2Cl2
11‚0.5C7H8
formula
C40H59P3Pt
C48H75P3Pt
C34H54IP3Pt
C34H54ClP3-
Pt‚C6D6
870.33
P212121
9.935(2)
17.704(4)
22.109(5)
90
C50H80P4Pt
C40H60P3Pt-
BF4‚CH2Cl2
998.60
P212121
11.0214(18)
13.219(2)
30.925(5)
90
C34H55ClP3Pt-
BF4‚CH2Cl2
874.04
P212121
8.326(4)
20.847(10)
23.51(11)
90
90
90
4081(19)
4
1.561
C75H116Cl2O2-
P6Pt2
1696.58
P21
10.049(2)
40.208(8)
10.130(2)
90
107.384(3)
90
formula wt
space group
a, Å
b, Å
c, Å
827.87
P212121
10.3213(18)
15.712(3)
28.338(5)
90
939.58
P21
12.5490(9)
23.1943(16)
18.1986(12)
90
96.7110(10)
90
5260.7(6)
4
877.67
P212121
10.2606(10)
18.4791(19)
41.283(4)
90
1000.11
P212121
9.9966(15)
19.761(2)
24.836(4)
90
R, deg
â, deg
90
90
90
90
90
90
90
90
90
90
γ, deg
V, Å3
4595.7(14)
4
1.197
7827.5(14)
8
1.490
3888.7(14)
4
1.486
4906.1(12)
4
1.354
4505.6(13)
4
1.472
3906.1(14)
2
1.442
Z
D(calcd), g/cm3
µ(Mo KR),
mm-1
1.186
2.785
3.179
4.516
3.827
3.022
3.383
3.795
3.810
temp, K
R(F), %b
Rw(F2), %b
218(2)
3.26
8.55
213(2)
4.72
11.41
203(2)
3.86
8.72
100(2)
4.23
9.33
100(2)
2.84
5.36
218(2)
2.90
6.38
208(2)
6.41
12.29
208(2)
4.91
11.61
a A Bruker CCD diffractometer was used in all cases. b Quantity minimized: Rw(F2) ) ∑[w(Fo2 - Fc )2]/∑[(wFo )2]1/2; R ) ∑∆/∑(Fo), ∆ ) |(Fo - Fc)|;
2
2
w ) 1/[σ2(Fo ) + (aP)2 + bP], P ) [2Fc + Max(Fo ,0)]/3.
2
2
2
Table 4. Selected Bond Lengths and Angles for the Phosphido Complexes Pt((R,R)-Me-Duphos)(Ph)(PMeIs) (1),
Pt((R,R)-i-Pr-Duphos)(Ph)(PMeIs) (2), Pt((R,R)-Me-Duphos)(I)(PMeIs) (3), Pt((R,R)-Me-Duphos)(Cl)(PMeIs)‚C6D6 (4‚C6D6), and
Pt((R,R)-Me-Duphos)(PMeIs)2 (5) and the Previously Reported Pt((R,R)-Me-Duphos)(H)(PPhIs) (C) and
Pt((R,R)-Me-Duphos)(Me)(PPh(i-Bu)) (D)a
1
2b
3b
4‚C6D6
5c
Cd
Df
Pt-P1
Pt-P2
Pt-P3
Pt-X
2.2849(14)
2.3028(13)
2.3761(13)
2.070(5)
2.288(2)
2.293(2)
2.370(2)
2.073(9)
2.2962(18)
2.2267(18)
2.3996(19)
2.6496(6)
2.2851(15)
2.2050(16)
2.3926(16)
2.3802(15)
2.3063(10)
2.3103(10)
2.4117(10)
2.3859(10)
2.226(4)
2.298(5)
2.335(5)
NDe
2.243(3)
2.273(3)
2.372(4)
2.13(3)g
P1-Pt-P2
P1-Pt-P3
P1-Pt-X
P2-Pt-P3
P2-Pt-X
P3-Pt-X
P3 angles
85.66(5)
86.07(9)
175.60(9)
89.7(3)
94.98(9)
172.6(3)
88.7(3)
86.35(6)
172.28(7)
87.67(5)
93.36(6)
171.60(4)
92.44(5)
98.5(3)
110.6(2)
112.2(3)
321.3(3)
87.56(6)
173.38(6)
86.45(5)
91.11(6)
172.72(6)
94.36(5)
97.4(3)
106.1(2)
113.03(19)
316.5(4)
84.98(4)
173.89(4)
94.84(4)
89.18(3)
176.83(3)
91.09(3)
93.43(18)
114.85(14)
113.13(12)
321.41(18)
86.83(18)
169.72(18)
NDe
86.44(12)
177.4(4)
91.6(7)g
90.45(12)
171.0(9)g
91.5(7)g
98.4(11)
109.7(5)
98.1(9)
171.47(5)
89.83(14)
97.37(5)
173.81(15)
86.51(14)
98.8(2)
109.95(15)
111.89(19)
320.6(2)
100.89(16)
NDe
NDe
98.2(4)
102.2(5)
112.5(4)
111.9(4)
326.6(5)
111.4(4)
113.7(3)
323.3(4)
∑P3 angles
306.2(11)
a Labeling of the phosphorus atoms is as in Table 1: P3 ) phosphido, P1 ) trans Duphos, P2 ) cis Duphos. Note that the labeling shown in ORTEP
diagrams of complexes 2 and 4 (Figures 2 and 4) is slightly different. In bis-phosphido complex 5, X ) PMe(Is), P4 is cis to P1 and trans to P2. b Two
molecules in the unit cell; average bond lengths and angles are reported. c The “P3 angles” and “ΣP3 angles” entries for 5 are average values for the two
phosphido ligands, P3 and P4. d See ref 15b. e The hydride ligand was not located in C, so associated bond lengths and angles were not determined (ND).
f Reference 15c. g The Pt-Me group in D was disordered over two positions; average bond lengths and angles are reported.
31P NMR data indicate the opposite ordering (JPt-P trans to Ph
> JPt-P trans to PMeIs; see Table 1).18 The Pt-halide bonds in
the iodo complex 3 (2.6496(6) Å) and chloro complex 4 (2.3802-
(15) Å) were essentially unchanged from those in Pt((R,R)-Me-
Duphos)I2 (2.6434(10) and 2.6151(11) Å)8 and Pt((R,R)-Me-
Duphos)Cl2‚CH2Cl2 (2.3828(12) and 2.3881(12) Å).10
Phosphido complexes 1-5 adopted approximate square-
planar geometries, with minor distortions. The angles at the
PMeIs group varied little in the series, with the sum ranging
from 316.5(4) to 323.3(4)°. In comparison to idealized values
of 328.5° for a tetrahedral geometry and 360° for trigonal-planar
coordination, these observations are as expected for pyramidal
phosphido ligands with a stereochemically active lone pair.19
The smaller angle sum observed for the PPh(i-Bu) ligand in D
suggests that steric effects are important in controlling the
geometry at the phosphido P.
Figure 5. ORTEP diagram of Pt((R,R)-Me-Duphos)(PMeIs)2 (5).
bonds reflected the trans influence, with those trans to Ph in 1
and 2 (2.3028(13) and 2.293(2) Å, respectively) and PMeIs in
(18) Appleton, T. G.; Clark, H. C.; Manzer, L. E. Coord. Chem. ReV.
1973, 10, 335-422.
(19) Wicht, D. K.; Paisner, S. N.; Lew, B. M.; Glueck, D. S.; Yap, G.
P. A.; Liable-Sands, L. M.; Rheingold, A. L.; Haar, C. M.; Nolan, S. P.
Organometallics 1998, 17, 652-660.
5 (2.3063(10) and 2.3103(10) Å) longer than the ones trans to
I in 3 (2.2267(18) Å) and to Cl in 4 (2.2050(16) Å). The internal
comparison in 1 (and 2) suggests that Ph has a larger trans
influence than PMeIs, although the differences are small and

5440 Organometallics, Vol. 25, No. 22, 2006
Scriban et al.
Table 5. 31P{1H} NMR Data for the Cationic Secondary Phosphine Complexes 6-10 and Secondary Phosphido Oxide
Complexes 11 and 12a
complex
δ(P1) (JPt-P
)
δ(P2) (JPt-P
)
δ(P3) (JPt-P
)
J12
J13
J23
drb
14
[Pt(Me-Duphos)(Ph)(PHMeIs)][BF4](6a)
63.1 (2623)
61.4 (2618)
58.4 (2681)
57.1 (2687)
74.8 (2321)
73.4 (2289)
78.9 (2380)
78.8 (2356)
69.9 (2188)
78.2 (2275)
68.1 (2158)
64.9 (1452)
65.7f
62.8 (1643)
67.6 (1691)
57.3 (1656)
53.7 (1631)
65.0 (3102)
72.0 (3175)
62.9 (3282)
65.4 (3312)
-62.6 (2513)
-55.2 (2472)
-66.1 (2510)
-60.3 (2481)
-72.0 (2213)
-65.8 (2164)
-60.3 (2227)
-53.5 (2230)
-71.6 (2200)
-68.0 (2237)e
-70.9 (2160)e
64.7 (2796)
60.8f
8
6
6
5
372
376
372
377
374
383
377
379
298d
289
296
431
432
365
360
18
18
17
17
18
15
18
17
6b
1
[Pt(i-Pr-Duphos)(Ph)(PHMeIs)][BF4] (7a)
1.3b
7b
1b
[Pt(Me-Duphos)(I)(PHMeIs)][BF4] (8a)
3
1
1
1.4
3.8
1
1.1
28
8b
[Pt(Me-Duphos)(Cl)(PHMeIs)][BF4] (9a)
3
3
9b
[Pt(Me-Duphos)(PHMeIs)2][OTf]2 (10a)c
10b
10c
19
24
16
17
Pt(Me-Duphos)(Cl)(P(O)MeIs) (11a)
56.0 (3918)
60.1 (3913)
9
9
11b
1
1
1
Pt(Me-Duphos)(P(O)MeIs)2 (12a)g
60.6 (1656)
51.3 (1864)
50.4 (2954)
48.1 (3185)
12b
a All Duphos ligands have the R,R configuration. The solvent was CD2Cl2, and the temperature was 21 °C. Coupling constants are given in Hz, with 85%
H3PO4 as the external chemical shift standard. Complexes 6-9 were mixtures of two diastereomers, while 10 was a mixture of three diastereomers; one gave
a well-resolved AA′XX′ pattern, while PHMe(Is) signals for the others were broad. See the Experimental Section for details. b dr ) diastereomer ratio, from
31P NMR integration after recrystallization. The initial ratio for 7 was 1.3:1, but recrystallization gave pure 7a. c Spectra and diastereomer ratio for the BF4
salt were similar. d AA′XX′ pattern with JAX ) 298, JAX′ ) -24, JAA′ ) 32, JXX′ ) 0. e Broad peaks. f Low concentration of the minor diastereomer 11b
precluded measurement of JPt-P
JPP coupling could be extracted.
.
g The 31P NMR resonances for 12 were complicated multiplets consistent with AA′XX′ patterns from which the large trans
Scheme 4a
Scheme 5a
a [Pt] ) Pt((R,R)-Me-Duphos).
As observed previously, protonation or oxidation resulted in
increases in JPP (trans) and JPt-P, consistent with increased s
character in the Pt-P bond in the secondary phosphine and
phosphido oxide complexes (see Table 5 for NMR data).19 Note
that, in one diastereomer of 11, the 31P NMR signals of the
P(O)Me(Is) group and the Duphos P trans to it were accidentally
coincident, and assignment was based on the relative JPt-P values
for these signals.22
X-ray crystallographic studies on 6, 9, and 11 demonstrated
the effects of protonation or oxidation of the phosphido
complexes on their structures (Tables 3 and 6). A single crystal
of 6‚CH2Cl2 had the RP absolute configuration (Figure 6), as
observed for the neutral precursor 1, but the analogous chloro
cation 9‚CH2Cl2 was SP (Figure 7). Two molecules of 11‚
0.5C7H8 were found in the unit cell; both had the RP absolute
configuration (Figure 8). Comparison of the structures in Figures
6 and 8 with those of their precursors in Figures 1 and 4 showed
that, before and after quaternization at phosphorus, the confor-
mations of the bulky groups were very similar. Although the
SP configuration in 9‚CH2Cl2 is unusual in this series, bond
a [Pt] ) Pt((R,R)-Me-Duphos), except for 2 and 7, for which [Pt] )
Pt((R,R)-i-Pr-Duphos).
Protonation and Oxidation of the Phosphido Complexes.
Protonation of the phosphido complexes 1-4 with HBF4 gave
the secondary phosphine complexes 6-9 (Scheme 4), some of
which were briefly mentioned above (Scheme 3). Initially, 6
and 7 were formed as 1:1 mixtures of diastereomers, but on
standing in solution (for 6) or recrystallization (7) one diaste-
reomer was formed preferentially.15a,20 Protonation of the bis-
(phosphido) complex 5 gave the bis(phosphine) dication 8 as a
mixture of three of the expected four diastereomers.
Similarly, oxidation of 4 and 5 using H2O2 gave the phosphido
oxide complexes 11 and 12, in both cases as a mixture of two
diastereomers (Scheme 5).21 The diastereomer ratios of these
products (11:1 and 1:1, respectively) were similar to those of
the starting materials (Table 1), which might be explained if
both phosphido diastereomers react at the same rate with H2O2.
However, faster oxidation of the minor diastereomer of 4, along
with rapid diastereomer interconversion, could also result in a
large product ratio.
(22) On oxidation of trans-Pt(PCy2H)2(PCy2)(Cl) to trans-Pt(PCy2H)2-
(P(O)Cy2)(Cl) (Mastrorilli, P.; Nobile, C. F.; Fanizzi, F. P.; Latronico, M.;
Hu, C.; Englert, U. Eur. J. Inorg. Chem. 2002, 1210-1218. Mastrorilli, P.;
Latronico, M.; Nobile, C. F.; Suranna, G. P.; Fanizzi, F. P.; Englert, U.;
Ciccarella, G. Dalton Trans. 2004, 1117-1119), JPt-P for the phosphido
ligand changed from 931 to 3078 Hz. Similarly, on oxidation of Pt(dppe)-
(Me)(PPh(i-Bu)) to Pt(dppe)(Me)(P(O)Ph(i-Bu)), JPt-P for the phosphido
ligand changed from 946 to 3006 Hz.15c
(20) (a) Bader, A.; Nullmeyers, T.; Pabel, M.; Salem, G.; Willis, A. C.;
Wild, S. B. Inorg. Chem. 1995, 34, 384-389. (b) References 7b,c.
(21) For other examples of oxidation of terminal phosphido complexes,
see refs 11, 15c, and 22, as well as: Gallo, V.; Latronico, M.; Mastrorilli,
P.; Nobile, C. F.; Suranna, G. P.; Ciccarella, G.; Englert, U. Eur. J. Inorg.
Chem. 2005, 4607-4616. Buhro, W. E.; Georgiou, S.; Hutchinson, J. P.;
Gladysz, J. A. J. Am. Chem. Soc. 1985, 107, 3346-3348.

Pt Duphos Terminal Phosphido Complexes
Organometallics, Vol. 25, No. 22, 2006 5441
Table 6. Selected Bond Lengths and Angles for the
Complexes Pt((R,R)-Me-Duphos)(Ph)(PMeIs) (1),
Pt((R,R)-Me-Duphos)(Cl)(PMeIs)‚C6D6 (4‚C6D6),
[Pt((R,R)-Me-Duphos)(Ph)(PHMeIs)][BF4]‚CH2Cl2
(6‚CH2Cl2), [Pt((R,R)-Me-Duphos)(Cl)(PHMeIs)][BF4]‚
CH2Cl2 (9‚CH2Cl2), and
Pt((R,R)-Me-Duphos)(Cl)(P(O)MeIs)‚0.5C7H8 (11‚0.5C7H8)a
c
1
6‚CH2Cl2 9‚CH2Cl2
4‚C6D6 11‚0.5C7H8
Pt-P1
Pt-P2
Pt-P3
Pt-X
2.2849(14) 2.2772(13) 2.279(3)
2.3028(13) 2.3096(11) 2.234(8)
2.3761(13) 2.3126(13) 2.347(3)
2.2851(15) 2.303(3)
2.2050(16) 2.221(3)
2.3926(16) 2.355(3)
2.3802(15) 2.367(3)
2.070(5)
2.082(4)
2.356(7)
P1-Pt-P2 85.66(5)
85.52(4)
86.58(11) 87.56(6)
86.31(10)
P1-Pt-P3 171.47(5) 177.11(4) 177.27(11) 173.38(6) 177.46(11)
P1-Pt-X 89.83(14) 90.21(13) 87.19(12) 86.45(5)
P2-Pt-P3 97.37(5) 96.82(4) 95.74(12) 91.11(6)
88.13(10)
92.79(10)
Figure 7. ORTEP diagram of [Pt((R,R)-Me-Duphos)(Cl)(PHMeIs)]-
[BF4]‚CH2Cl2 (9‚CH2Cl2). The anion and the disordered solvent
molecule are not shown.
P2-Pt-X 173.81(15) 172.02(16) 170.97(10) 172.72(6) 171.67(12)
P3-Pt-X 86.51(14) 87.26(13) 90.34(12) 94.36(5)
92.51(10)
109.4(6)
(av)d
P3 angles 98.8(2)
103.9(13)b 107.7(6)b 97.4(3)
109.95(15) 120.38(15) 112.1(4)
111.89(19) 118.19(19) 124.1(4)
320.6(2) 342.47(19) 343.9(6)
106.1(2)
113.03(19)
316.5(4)
∑P3
angles
e
a
Labeling of the phosphorus atoms is as in Table 1: P3 ) phosphido
(secondary phosphine in 6 and 9, phosphido oxide in 11), P1 ) trans
Duphos, P2 ) cis Duphos. Note that the labelings shown in the ORTEP
diagrams of complexes 4 and 7 (Figures 4 and 7) are slightly different.
b The P-H hydrogen atom was not located; therefore, the P3 angles involve
only the Pt and C substituents. c Two independent molecules in the unit
cell. Average bond lengths and angles are reported. d Average angle at P3
for the two independent molecules. e Complex 11 is unique in that bond
angles involving all four P substituents could be measured (for the other
complexes only three were available).
Figure 8. ORTEP diagram showing one of the two molecules of
Pt((R,R)-Me-Duphos)(Cl)(P(O)MeIs)‚0.5C7H8 (11‚0.5C7H8) in the
unit cell. Hydrogen atoms and the solvent molecule are omitted.
protonation led to a longer Pd-P bond.13 Perhaps the constraints
of the chelate ring in this case controlled the structural changes.
On protonation of 1, the Pt-Ph and Pt-P2 (trans to Ph) bonds
became slightly longer, changing from 2.070(5) to 2.082(4) Å
and from 2.3028(13) to 2.3096(11) Å, respectively. The Pt-
P2 (trans to Cl) bond in 9 also became longer (from 2.2050-
(16) to 2.234(8) Å), but the Pt-Cl bond contracted on
protonation (from 2.3802(15) to 2.356(7) Å), perhaps as a result
of increased Pt-Cl Coulombic attraction in the cation. The Pt-
P1 (trans to PMeIs/PHMeIs) bonds in both pairs shortened from
2.2849(14) to 2.2772(13) Å in 1/6 and from 2.2851(15) to 2.279-
(3) Å in 4/9, which suggests that the phosphido group has a
larger trans influence than the secondary phosphine. This is
consistent with the NMR data; JPt-P values for the Duphos P
trans to PMeIs and PHMeIs in 1/6 were 1869 Hz (C6D6, room
temperature) and 2620 Hz (CD2Cl2, average for the two
diastereomers), respectively, while the values for 4/9 were 1637
Hz (THF-d8, -20 °C, average for the two diastereomers) and
2368 Hz (CD2Cl2, average for the two diastereomers).18
However, an opposite structural result was observed for both
the Pd and the Ir complexes cited above. Reaching general
conclusions on the structural effects of phosphido protonation,
therefore, will require crystallographic studies of more such pairs
of complexes.
Figure 6. ORTEP diagram of [Pt((R,R)-Me-Duphos)(Ph)(PHMeIs)]-
[BF4]‚CH2Cl2 (6‚CH2Cl2). Hydrogen atoms, the BF4 anion, and the
solvent molecule are not shown.
lengths and angles in this structure showed no unusual features
in comparison to the RP analogues.
Protonation (1 f 6, 4 f 9) resulted in significant structural
changes (Table 6). Each of the P3 (phosphido/secondary
phosphine) angles increased, consistent with the reduced steric
demands of a proton in comparison to the P lone pair. The Pt-
P3 (phosphido) bond shortened from 2.3761(13) to 2.3126(13)
Å in 1/6 and from 2.3926(16) to 2.347(3) Å in 4/9. These
changes, which could be ascribed to removing repulsive Pt-P
π interactions on protonation,23 were also observed in the
conversion of trans,mer-[IrCl2(PMe2Ph)3(PH2)] to trans,mer-
[IrCl2(PMe2Ph)3(PH3)]+,24 but in the cyclometalated phosphido
complex Pd(dppe)(CH2C6H2Me2P(Mes)) (Mes ) 2,4,6-Me3C6H2),
Similarly, comparison of the structure of the phosphido
complex 4 with that of its oxide 11 revealed effects similar to
(23) (a) Caulton, K. G. New J. Chem. 1994, 18, 25-41. (b) Holland, P.
L.; Andersen, R. A.; Bergman, R. G. Comments Inorg. Chem. 1999, 21,
115-129.
(24) Deeming, A. J.; Doherty, S.; Marshall, J. E.; Powell, J. L.; Senior,
A. M. J. Chem. Soc., Dalton Trans. 1993, 1093-1100.

5442 Organometallics, Vol. 25, No. 22, 2006
Scriban et al.
Scheme 6a
Scheme 7a
a [Pt] ) Pt((R,R)-Me-Duphos), L ) P(o-Tol)3.
Tol)3)2 gave an apparent equilibrium mixture containing 1, Pd-
(P(o-Tol)3)2, the two-coordinate palladium complex Pd(P(o-
Tol)3)(µ-PMeIs)Pt((R,R)-Me-Duphos)(Ph) (14), and P(o-Tol)3
(Scheme 7).28 Formation of the products 14 and P(o-Tol)3 was
clearly favored, but the low solubility of Pd(P(o-Tol)3)2
prevented us from measuring Keq. Additional 1 did not displace
P(o-Tol)3 from 14 at room temperature, and no exchange
between 14 and P(o-Tol)3 was observed on the NMR time scale.
Attempts to isolate 14 were unsuccessful, but it could be
characterized in the mixture as a 1:1 mixture of diastereomers
by 31P NMR spectroscopy. These diastereomers might differ in
the absolute configuration at the µ-PMeIs group or result from
slow rotation on the NMR time scale about the M-P bonds.
Quaternization of the phosphido group led to increased
JPP(trans) (from 133 to 246 Hz (average)) and JPt-P (from 899 to
1550 Hz (average)) couplings in the Pt(Me-Duphos)(PMeIs)
group, as observed for protonation and oxidation (see Table 5).
Similarly, JPt-P for the Duphos P trans to PMeIs increased from
1621 to 1842 Hz (average), consistent with a decreased trans
influence for the bridging phosphido ligand.
a [Pt] ) Pt((R,R)-Me-Duphos), L ) PMeIs(allyl).
those of protonation. On oxidation, the Pt-P3 bond shortened
from 2.3926(16) to 2.355(3) Å, consistent as in the protonation
case with erasing the repulsive Pt-P lone pair interaction. The
phosphido P went from pyramidal (angle sum 316.5(4)°;
compare 328.5° for the ideal tetrahedral geometry) to tetrahedral
(average P angle 109.4(6)°), also consistent with removing the
stereochemically active lone pair. The Pt-P2 bond lengthened
slightly (from 2.2050(16) to 2.221(3) Å), while the Pt-Cl bond
became shorter (2.3802(15) vs 2.367(3) Å), as observed for
protonation (4 and 9). The Pt-P1 distance (trans to PMeIs/
P(O)MeIs) changed from 2.2851(15) to 2.303(3) Å, suggesting
a greater trans influence for the phosphido oxide ligand. This
is consistent with the 31P NMR data; JPt-P for the trans Duphos
P changed from 1637 Hz (average for the two diastereomers)
to 1452 Hz (major diastereomer; JPt-P was not observed for
the minor one) on oxidation. The resulting trans influence order,
from crystallographic and NMR data on chloro complexes 4,
9, and 11, is then P(O)MeIs > PMeIs > PHMe(Is).
Conclusions
We prepared a series of Pt(Duphos) terminal phosphido
complexes (1-5). The phosphido ligand, with a small methyl
and a large isityl group, was intended to result in steric
differentiation between the diastereomers of these complexes,
causing a thermodynamic preference for one of them. As
desired, this was observed, and the expected low barriers to
inversion in the phosphido complexes were quantified by NMR
spectroscopy. Despite the thermodynamic preference for one
diastereomer of 1 and 2, protonation gave kinetic mixtures of
the secondary phosphine cationic complexes 6 and 7, suggesting
that the minor diastereomer reacted more quickly than the major
one. Two of the four diastereomers of the bis(phosphido)
complex 5 were favored, with similar results for the protonated
dication 10 and the oxidized derivative 12.
Complex 1, with a large thermodynamic preference for one
diastereomer, was designed to serve as a “self-resolving”
metallophosphine. However, an attempt to complex it to the
Pd(allyl) fragment resulted in phosphido transfer from Pt to the
allyl group. More successful was the reaction of 1 with PdL2
(L ) P(o-Tol)3). In this case, however, a ca. 1:1 mixture of
diastereomeric Pt-Pd complexes 12 was formed in an apparent
equilibrium. This points to a weakness in the original plan. It
is not enough to design a P-stereogenic metallophosphine which
exists primarily as a single diastereomer; it must also retain this
P-based chirality on complexation. Moreover, the large size of
metalloligand 1, required for thermodynamic diastereoselection,
presumably destabilized 14 sterically, contributing to its forma-
tion in an equilibrium. We are continuing studies of such
metalloligands with these ideas in mind, in hopes of realizing
highly selective, irreversible binding.
31P NMR data on the bis(phosphido) complex 5 (Table 5)
and its doubly protonated and oxidized derivatives 10 and 12
provided a similar ordering. Here, as in 4 and 11, the average
JPt-P for the trans Duphos P changed little on oxidation (from
1766 to 1760 Hz) but increased significantly on protonation
(to 2207 Hz).
Pt(Duphos) Phosphido Complexes as Metalloligands. Since
one diastereomer of 1 was thermodynamically favored, as
desired (Chart 1), we briefly explored its metalloligand proper-
ties. Instead of complexation of the Cr(CO)5 group (see Scheme
1), however, Pd moieties with potential use in catalysis were
targeted.
Reaction with [Pd(allyl)Cl]2 gave Pt((R,R)-Me-Duphos)(Ph)-
(Cl) as the major Pt(Duphos)-containing product (Scheme 6).
A mixture of complexes we presume to be the zerovalent Pd-
[(PMeIs(allyl))]n was also observed by 31P NMR spectroscopy.
On treatment with excess dppe, these compounds disappeared,
and Pd(dppe)2 and the new phosphine PMeIs(allyl) (11) were
formed.25 After chromatographic separation, phosphine 13 was
isolated in 71% yield (94% purity, 51% ee) and identified by
NMR and high-resolution mass spectroscopy.26 This reaction
might occur by P-C reductive elimination from intermediate
G6 or by direct nucleophilic attack on the Pd-allyl group.27
Another approach to bimetallic phosphido-bridged Pt-Pd
complexes was more successful. Treatment of 1 with Pd(P(o-
(25) Rosevear, D. T.; Stone, F. G. A. J. Chem. Soc. A 1968, 164-167.
1
(26) The H and 13C NMR spectra of PMe(Is)(allyl), in comparison to
those for PMe2(allyl) (see Bampos, N.; Field, L. D.; Messerle, B. A.;
Smernik, R. J. Inorg. Chem. 1993, 32, 4084-4088), were consistent with
this formulation.
(27) The analogous reaction of Ru(Cp)(PEt3)2(PPh2) with [Pd(allyl)-
(NCPh)2][BF4] gave a mixture of the cations [Cp(PEt3)2Ru(µ-PPh2)Pd-
(NCPh)(allyl)]+ and the allylphosphine complex [Ru(Cp)(PEt3)2(PPh2-
(allyl))]+.11
(28) Paul, F.; Patt, J.; Hartwig, J. F. Organometallics 1995, 14, 3030-
3039. For use of Pd(P(o-Tol)3)2 in the synthesis of other PdL2 complexes,
see: Mann, G.; Shelby, Q.; Roy, A. H.; Hartwig, J. F. Organometallics
2003, 22, 2775-2789.

Pt Duphos Terminal Phosphido Complexes
Organometallics, Vol. 25, No. 22, 2006 5443
(broad, 2C, Is meta), 44.1 (d, J ) 30, CH Duphos), 41.9-41.4 (m,
CH Duphos), 37.8 (CH2), 36.3 (CH2), 35.5 (overlapping CH2 and
CH, Is), 34.7 (CH, Is), 34.3 (CH, Is), 32.8-32.1 (overlapping m
and d, J ) 42, 2CH Duphos), 27.2 (broad, CH3, Is), 24.5 (CH3,
Is), 22.6 (CH3, Is), 18.1 (dd, J ) 20, 9, CH3, Duphos), 15.6 (d, J
) 9, CH3, Duphos), 14.8 (d, J ) 3, CH3, Duphos), 14.5 (d, J ) 2,
CH3, Duphos), 12.5-12.0 (m, P-CH3). 31P{1H} NMR (C6D6): δ
58.3 (broad, JPt-P ) 1869), 57.6 (dd, J ) 133, 8, JPt-P ) 1621),
-51.8 (broad d, J ) 133, JPt-P ) 899). See Table 1 for
low-temperature 31P NMR data (four diastereomers).
Experimental Section
All reactions and manipulations were performed in dry glassware
under a nitrogen atmosphere at 20 °C in a drybox or using standard
Schlenk techniques. Petroleum ether (bp 38-53 °C), ether, THF,
toluene, and CH2Cl2 were dried using columns of activated
alumina.29 NMR spectra were recorded using Varian 300 and 500
MHz spectrometers. 1H and 13C NMR chemical shifts are reported
vs Me4Si and were determined by reference to the residual 1H and
13C solvent peaks. 31P NMR chemical shifts are reported vs H3PO4
(85%) used as an external reference. Coupling constants are reported
in Hz, as absolute values unless noted otherwise. Unless indicated,
peaks in NMR spectra are singlets. Elemental analyses were
provided by Schwarzkopf Microanalytical Laboratory or Quantita-
tive Technology Inc. Mass spectra were recorded at the University
of Illinois Urbana-Champaign.
Unless otherwise noted, reagents were from commercial suppli-
ers. The following compounds were made according to literature
methods: Pt(COD)(Ph)Cl) (COD ) cyclooctadiene),30 Pt((R,R)-
Me-Duphos)Cl2,10 Pt((R,R)-Me-Duphos)I2 and Pt((R,R)-Me-Du-
phos)(Ph)(Cl),8 (S)-{Pd[NMe2CH(Me)C6H4](Cl)}2,31 PHMe(Is),9
and Pd(P(o-Tol)3)2.28
Pt((R,R)-Me-Duphos)(Ph)(PMeIs) (1). PHMe(Is) (141 mg, 0.56
mmol) was added with a microsyringe to a stirred slurry of Pt-
((R,R)-Me-Duphos)(Ph)(Cl) (346 mg, 0.56 mmol) in toluene (10
mL). NaOSiMe3 (63.3 mg, 0.56 mmol) in toluene (10 mL) was
added to the reaction mixture. As soon as Pt((R,R)-Me-Duphos)-
(Ph)(Cl) reacted, the mixture turned yellow; it was stirred for ∼3
h. The slurry was filtered through Celite, and the yellow filtrate
was concentrated under vacuum. Petroleum ether was added to the
yellow residue, yielding yellow crystals, which were washed further
with petroleum ether and dried under vacuum, giving 415.5 mg
(89%) of yellow crystals suitable for X-ray crystallography.
Anal. Calcd for C40H59P3Pt: C, 58.03; H, 7.18. Found: C, 56.29;
H, 7.41. Elemental analyses for carbon were consistently low,
perhaps due to decomposition of the air-sensitive complex. Anal.
Calcd for C40H59P3PtO: C, 56.93; H, 7.05. We previously observed
that the analogous Pt(Duphos) phosphido complex Pt((R,R)-Me-
Duphos)(H)(PPhIs) also failed to give satisfactory analyses.15b Since
we could not obtain good analyses on this or the other Pt-
phosphido complexes, we protonated them with HBF4 and isolated
the resulting secondary phosphine complexes in analytically pure
form after recrystallization (see below and refs 11 and 12). HRMS
(m/z): calcd for C40H60P3Pt (MH+), 828.3569; found, 828.3571.
Complex 1 could also be prepared by deprotonation of the cation
[Pt((R,R)-Me-Duphos)(Ph)(PHMe(Is))][OTf] (6; see below) with
NaN(SiMe3)2 or other bases.
1H NMR (C6D6): δ 8.07 (t, J ) 6, JPt-H ) 51, 1H, Ph ortho),
7.68 (t, J ) 7, JPt-H ) 51, 1H, Ph ortho), 7.37 (t, J ) 7, 1H, Ar),
7.29 (t, J ) 7, 1H, Ar), 7.21-7.18 (t, J ) 6, 1H, Ar), 7.16 (2H,
Is), 7.13-7.11 (m, 1H, Ar), 7.04 (t, J ) 7, 1H, Ar), 6.97-6.90 (m,
2H, Ar), 5.16 (broad, 2H, CH, Is), 3.01-2.94 (m, 1H, CH), 2.89-
2.81 (m, 1H, CH), 2.36-2.28 (m, 1H, CH), 2.17-2.08 (m, 1H,
CH), 1.81-1.67 (m, 3H), 1.62 (dd, J ) 17, 6, 6H, Me), 1.51 (d, J
) 7, 6H, Me), 1.48-1.43 (m, 3H, P-Me), 1.40 (dd, J ) 18, 7,
6H, Me), 1.28 (d, J ) 8, 3H, Me), 1.27 (d, J ) 7, 3H, Me), 0.99
(qd, J ) 13, 5, 1H), 0.90-0.80 (m, 1H), 0.64 (dd, J ) 14, 7, JPt-H
) 53, 3H, Me), 0.58 (dd, J ) 15, 8, 3H, Me). 13C{1H} NMR
(C6D6): δ 154.7 (quat, Ar), 147.7 (quat, Ar), 147.2 (quat, Ar),
143.9-143.5 (m, Ar), 139.9 (Ph ortho), 137.6 (broad, Ph ortho),
133.1 (dd, J ) 86, 14, Duphos), 130.0 (d, J ) 78, Duphos), 128.2-
127.7 (m, Ar overlapping with C6D6 signals), 122.2 (Ph para), 120.5
Pt((R,R)-i-Pr-Duphos)(Ph)(Cl). A solution of (R,R)-i-Pr-Duphos
(293 mg, 0.7 mmol) in CH2Cl2 (2 mL) was added dropwise to a
solution of Pt(COD)(Ph)(Cl) (291 mg, 0.7 mmol) in CH2Cl2 (3 mL)
to give a colorless solution. In the air, the solvent was removed
under reduced pressure and the remaining crystals were washed
with diethyl ether (3 × 2 mL) and recrystallized from CH2Cl2/
diethyl ether at -25 °C to yield 350 mg (70%) of white Pt((R,R)-
i-Pr-Duphos)(Ph)(Cl).
Anal. Calcd for C32H49ClP2Pt: C, 52.92; H, 6.80. Found: C,
52.79; H, 6.41. 31P{1H} NMR (C6D6): δ 58.8 (d, J ) 3, JPt-P
)
1
1627), 47.2 (d, J ) 3, JPt-P ) 3944). H NMR (C6D6): δ 7.96 (t,
J ) 7, JPt-H ) 36, 2H), 7.36-7.32 (m, 3H), 7.20-7.16 (m, 1H),
7.10 (t, J ) 8, 1H), 7.07-7.00 (m, 2H), 3.38-3.21 (m, 1H), 3.08-
3.00 (m, 1H), 2.85-2.76 (m, 1H), 2.55-2.45 (m, 1H), 2.29-2.21
(m, 1H), 2.13-2.03 (m, 2H), 2.02-1.92 (m, 2H), 1.75-1.36 (m,
6H), 1.19 (d, J ) 7, 3H, Me), 1.15 (d, J ) 7, 3H, Me), 1.12-1.03
(m, 1H), 0.99 (d, J ) 7, 3H, Me), 0.91 (d, J ) 7, 3H, Me), 0.80 (d,
J ) 7, 3H, Me), 0.71 (d, J ) 7, 3H, Me), 0.64 (d, J ) 7, 3H, Me),
0.56 (d, J ) 7, 3H, Me). 13C{1H} NMR (C6D6): δ 161.5 (dd, J )
120, 8, quat, Pt-Ph), 145.3 (dd, J ) 45, 38, quat Ar), 144.3 (dd,
J ) 32, 24, quat Ar), 139.3 (Ph), 133.9 (d, J ) 13, Ar), 133.1 (dd,
J ) 15, 4, Ar), 131.4-131.2 (m, Ar), 131.1-130.9 (m, Ar), 128.6
(d, J ) 7, Ph), 123.6 (Ph), 54.7 (d, J ) 23, CH), 53.8 (d, J ) 38,
CH), 48.0 (d, J ) 24, CH), 46.6 (d, J ) 34, CH), 31.9, 31.7, 31.4,
30.5 (d, J ) 8), 30.4 (d, J ) 7), 30.0 (d, J ) 5), 29.4 (d, J ) 2),
28.4 (m), 26.3 (d, J ) 7, Me), 26.1 (d, J ) 4, Me), 25.5 (d, J ) 6,
Me), 24.6 (d, J ) 6, Me), 22.2 (d, J ) 11, Me), 21.9 (d, J ) 9,
Me), 21.5 (d, J ) 6, Me), 21.3 (d, J ) 8, Me).
Pt((R,R)-i-Pr-Duphos)(Ph)(PMeIs) (2). PHMe(Is) (112.5 mg,
0.45 mmol) was added with a microsyringe to a stirred slurry of
Pt((R,R)-i-Pr-Duphos)(Ph)(Cl) (327 mg, 0.45 mmol) in THF (20
mL). NaOSiMe3 (50.5 mg, 0.45 mmol) in toluene (10 mL) was
added to the reaction mixture. The mixture turned yellow im-
mediately. The solvent was removed under vacuum, and toluene
(20 mL) was added to the residue. The toluene slurry was filtered
through Celite, and the yellow filtrate was concentrated under
vacuum. Petroleum ether was added to the yellow residue. The
yellow solution was stored at -25 °C for 24 h, yielding yellow
crystals suitable for X-ray crystallography, and a yellow solution.
The yellow crystals were further washed with petroleum ether
(3 × 5 mL) and dried under vacuum, yielding 300 mg (71%) of
yellow crystals.
Anal. Calcd for C48H75P3Pt: C, 61.32; H, 8.04. Found: C, 59.14;
H, 7.90. Satisfactory analyses for C could not be obtained, perhaps
because of the air sensitivity of the complex (Anal. Calcd. for
C48H75P3PtO: C, 60.30; H, 7.91). Mass spectroscopy was also
consistent with oxidation. HRMS (FAB; m/z): calcd for C48H76-
OP3Pt+ (M(O)H+), 956.4771; found, 956.4668. 31P{1H} NMR (21
°C, THF-d8): δ 54.3 (d, J ) 131, JPt-P ) 1654), 50.8 (broad, JPt-P
) 1818), -60.0 (broad). See Table 1 for low-temperature 31P NMR
1
data (four diastereomers). H NMR (THF-d8): δ 7.88-7.86 (m,
1H, Ar, Duphos), 7.83-7.80 (m, 1H, Ar, Duphos), 7.57 (broad,
1H, Ph ortho), 7.48-7.43 (m, 2H, Ar, Duphos), 7.39 (broad t, J )
7, 1H, JPt-H ) 49, Ph ortho), 6.98 (broad t, J ) 8, 1H, Ph meta),
6.94 (broad, 1H, Ph para), 6.90 (2H, Is meta), 6.72 (broad t, J )
8, 1H, Ph meta), 4.68 (broad, 2H, CH, Is), 2.83-2.71 (m, 2H,
overlapping CH Duphos + CH Is), 2.70-2.62 (broad, 1H, CH
(29) Pangborn, A. B.; Giardello, M. A.; Grubbs, R. H.; Rosen, R. K.;
Timmers, F. J. Organometallics 1996, 15, 1518-1520.
(30) Clark, H. C.; Manzer, L. E. J. Organomet. Chem. 1973, 59, 411-
428.
(31) Tani, K.; Brown, L. D.; Ahmed, J.; Ibers, J. A.; Nakamura, A.;
Otsuka, S.; Yokota, M. J. Am. Chem. Soc. 1977, 99, 7876-7886.

5444 Organometallics, Vol. 25, No. 22, 2006
Scriban et al.
Duphos), 2.45-2.33 (m, 2H, 2CH Duphos), 2.30-2.16 (broad m,
1H, CH Duphos), 1.99-1.75 (m, 5H, CH + CH2), 1.75-1.68 (m,
2H, CH2), 1.64-1.55 (m, 2H, CH2), 1.49 (qd, J ) 13, 5, 2H, CH
Duphos), 1.25-1.18 (m, 18H, CH3), 1.05 (broad, 3H, CH3), 0.96-
0.82 (m, 9H, overlapping CH3 Duphos and P-Me), 0.68-0.62 (m,
9H, overlapping CH3), 0.49 (broad, 3H, CH3), 0.38 (broad, 3H,
CH3). 13C{1H} NMR (THF-d8): δ 161.4 (m, Pt-C, quat Ph), 155.0
(broad, quat Is), 149.0-148.5 (m, quat Duphos), 147.8 (quat Is),
145.2-144.7 (m, quat Duphos), 144.2 (m, quat Is), 140.3 (broad,
Ph ortho), 139.2 (Ph ortho), 135.5 (d, J ) 15, Ar, Duphos), 134.3
(d, J ) 12, Ar, Duphos), 131.3 (m, Ar, Duphos), 130.8 (m, Ar,
Duphos), 128.2 (d, J ) 6, Ph meta), 127.8 (m, Ph para), 122.2 (Ph
meta), 121.1 (Is), 57.2 (d, J ) 24, CH, Duphos), 55.9 (d, J ) 25,
CH, Duphos), 50.1 (broad m, CH, Duphos), 46.1 (d, J ) 23, CH
Duphos), 35.3 (CH, Is), 33.7 (d, J ) 17, CH, Is), 32.5 (CH,
Duphos), 31.6 (m, CH, Duphos), 31.1 (d, J ) 6, CH2), 30.9-30.5
(m, CH, Duphos), 30.1-29.8 (m, CH, Duphos), 29.8 (d, J ) 8,
CH2), 29.2 (CH2, Duphos), 27.9 (CH3), 26.9 (d, J ) 4, CH3), 26.5
(d, J ) 2, CH3), 25.1 (d, J ) 6, CH3), 24.6 (m, CH3, Is), 22.3 (d,
J ) 11, CH3), 22.2 (d, J ) 11, CH3), 21.1 (d, J ) 6, CH3), 20.0
(broad, CH3), 12.8 (broad m, P-CH3).
Pt((R,R)-Me-Duphos)(I)(PMeIs) (3). PHMe(Is) (91 mg, 0.36
mmol) was added with a microsyringe to a stirred slurry of Pt-
((R,R)-Me-Duphos)I2 (275 mg, 0.36 mmol) in toluene (10 mL).
NaOSiMe3 (40.8 mg, 0.36 mmol) in toluene (10 mL) was added
to the reaction mixture. The mixture turned yellow, and the solu-
tion became homogeneous after 10 min. The slurry was filtered
through Celite, and the yellow filtrate was concentrated under
vacuum. Petroleum ether was added to the yellow residue. The
solution was stored at -25 °C for 24 h, yielding yellow crystals
suitable for X-ray crystallography and a yellow solution. The
yellow crystals were further washed with petroleum ether (3 ×
5 mL) and dried under vacuum, yielding 250 mg (78%) of yellow
crystals.
(PHMeIs)][BF4] (9; see below; 100 mg, 0.11 mmol) in toluene
(1 mL). The reaction mixture turned yellow immediately. It was
filtered through Celite, the filtrate was concentrated under vacuum,
and the yellow residue was washed with petroleum ether (three
portions of 0.2 mL) and dried under vacuum, yielding 70 mg
(78%) of yellow powder. According to 31P NMR spectra, the sample
was contaminated with Pt(Me-Duphos)Cl2, Pt(Me-Duphos)(Cl)-
(OSiMe3) and Pt(Me-Duphos)(OH)(PMeIs) (∼5%). See below for
more spectroscopic data for these impurities.
Because complex 4 was not obtained in pure form, we could
not get satisfactory elemental analyses for it. Instead, protonation
and oxidation gave derivatives 9 and 11 (see below), which were
fully characterized. HRMS (m/z): calcd for C34H55ClOP3Pt (MHO+),
801.2781; found, 801.2793. 31P{1H} NMR (21 °C, THF-d8): δ 69.5
(broad d, J ) 122, JPt-P ) 1605), 53.9 (broad, JPt-P ) 4014), -36.0
(very broad, b), -55.0 (broad d, J ) 122, JPt-P ) 809, a). See
Table 1 for low-temperature 31P NMR data (two diastereomers).
1H NMR (21 °C, THF-d8): δ 7.86-7.82 (m, 1H, Ar), 7.69-7.63
(m, 1H, Ar), 7.60-7.53 (m, 2H, Ar), 6.96 (2H, Ar), 4.93 (broad,
2H), 3.34-3.23 (m, 1H), 3.05-2.92 (m, 1H), 2.87-2.77 (m, 1H),
2.60-2.46 (m, 1H), 2.40-2.28 (m, 2H), 2.22-2.12 (m, 1H), 2.09-
1.95 (m, 1H), 1.95-1.82 (m, 1H), 1.82-1.70 (m, 2H), 1.70-1.60
(m, 1H) overlapping with 1.67 (dd, J ) 8, 6, 3H, CH3), 1.52 (dd,
J ) 18, 7, 6H, CH3), 1.26-1.14 (overlapping m, 18H, CH3), 0.92
(m, 1H), 0.81 (dd, J ) 15, 8, 3H, CH3), 0.56 (broad, 3H, CH3). 1H
NMR (-20 °C, THF-d8): δ 7.92-7.87 (m, 1H, Ar), 7.72-7.66
(m, 1H, Ar), 7.65-7.56 (m, 2H, Ar), 6.97 (2H, Ar), 4.93 (broad d,
J ) 6, 2H, a), 4.49 (broad, 2H, b), 3.32-3.20 (m, 1H), 3.08-2.92
(m, 1H), 2.88-2.76 (m, 1H), 2.63-2.44 (m, 1H), 2.40-2.27 (m,
2H), 2.20-2.09 (m, 1H), 2.08-1.95 (m, 1H), 1.94-1.82 (m, 2H),
1.83-1.77 (m, 1H), 1.68-1.56 (overlapping m, 4H), 1.56-1.46
(m, 6H, Me), 1.26-1.18 (overlapping m, 12H, Me), 1.16 (d, J )
7, 6H, Me), 0.92-0.85 (m, 1H), 0.80 (dd, J ) 15, 7, 3H, Me),
0.53 (dd, J ) 16, 7, 3H, Me).
HRMS (m/z): calcd for C34H55IP3Pt (MH+), 877.2188; found,
877.1935. Anal. Calcd for C34H54IP3Pt: C, 46.53; H, 6.20. Found:
C, 35.09; H, 5.19. The poor analytical results presumably stem from
decomposition of the air-sensitive sample. 31P{1H} NMR (21 °C,
toluene-d8): δ 64.5 (broad d, J ) 117, JPt-P ) 1559), 54.4 (broad,
JPt-P ) 3943), -68.3 (broad, JPt-P ) 842). See Table 1 for low-
Pt((R,R)-Me-Duphos)(PMeIs)2 (5). Method I. PHMe(Is) (120
mg, 0.48 mmol) was added with a microsyringe to a stirred slurry
of Pt((R,R)-Me-Duphos)Cl2 (137 mg, 0.24 mmol) in toluene (1 mL).
NaOSiMe3 (53.8 mg, 0.48 mmol) in toluene (1 mL) was added to
the reaction mixture. The mixture turned orange, and the solution
became homogeneous after 30 min. The slurry was filtered through
Celite, and the orange filtrate was concentrated under vacuum.
Petroleum ether was added to the yellow residue. The solution was
stored at -25 °C for 24 h, yielding yellow crystals suitable for
X-ray crystallography and a yellow solution. The yellow crystals
were further washed with petroleum ether (3 × 1 mL) and dried
under vacuum, yielding 195 mg (81%) of yellow crystals. On the
basis of the 31P NMR spectra, the sample was contaminated with
Pt((R,R)-Me-Duphos)(Cl)(PMeIs) (4), Pt((R,R)-Me-Duphos)(OSiMe3)-
(PMeIs), Pt((R,R)-Me-Duphos)(OH)(PMeIs), PHMe(Is), and other
unidentified impurities (∼10% total, see below).
1
temperature 31P NMR data (two diastereomers). H NMR (21 °C,
toluene-d8): δ 7.25-7.19 (m, 1H, Ar), 7.18-7.12 (m, 3H, Ar),
7.08-7.04 (m, 2H, Ar), 5.21 (broad, 2H, CH), 3.97-3.87 (m, 1H,
CH), 2.87-2.80 (m, 1H, CH), 2.77-2.60 (broad, 3H), 2.58-2.49
(m, 2H), 2.36 (broad, 1H), 2.22-1.80 (m, 5H), 1.60 (dd, J ) 18,
7, 3H, CH3), 1.48 (d, J ) 8, 3H, CH3), 1.45 (d, J ) 7, 6H, 2CH3),
1.38 (d, J ) 7, 6H, 2CH3), 1.29 (d, J ) 7, 6H, 2CH3), 0.86 (d, J
) 7, 3H, CH3), 0.54 (dd, J ) 15, 7, 3H, CH3), 0.51 (dd, J ) 14,
7, 3H, CH3).
Pt((R,R)-Me-Duphos)(Cl)(PMeIs) (4). Method I. NaOSiMe3
(34 mg, 0.3 mmol) in toluene (0.5 mL) was added to a stirred slurry
of Pt((R,R)-Me-Duphos)Cl2 (172 mg, 0.3 mmol) in toluene (1 mL).
PHMeIs (75 mg, 0.3 mmol) was added to the reaction mixture,
which turned orange immediately. After 2 h, the slurry was filtered
through Celite, and the orange filtrate was concentrated under
vacuum. The orange residue was washed with petroleum ether (three
portions of 0.5 mL), yielding 200 mg (85%) of orange powder. A
C6D6 solution deposited yellow crystals suitable for X-ray crystal-
lography. The bulk sample contained ∼10% impurities. The major
impurity (∼7%), assigned as Pt(Me-Duphos)(OH)(PMeIs), appears
to be a mixture of two diastereomers, on the basis of the 31P NMR
spectrum (see below). This species was also observed as an impurity
in the 31P NMR spectrum of Pt(Me-Duphos)(PMeIs)2 (5; see below).
Complex 5 was also sometimes seen as an impurity when making
4 via this route.
Method II. To a slurry of [Pt((R,R)-Me-Duphos)(PHMeIs)2]-
[OTf]2 (10; see below; 70 mg, 0.054 mmol) in toluene (1 mL) was
added a slurry of NaOSiMe3 (12 mg, 0.11 mmol) in toluene
(1 mL). The reaction mixture turned yellow immediately. It was
filtered through Celite, and the filtrate was concentrated under
vacuum. The viscous residue was washed with petroleum ether
(3 × 0.5 mL) and dried under vacuum, yielding 45 mg (82%) of
yellow powder. On the basis of the 31P NMR spectra, the sample
was contaminated with Pt((R,R)-Me-Duphos)(Cl)(PMeIs) (4), PH-
Me(Is), and other unidentified impurities (∼10% total).
We could not obtain spectroscopically pure bulk samples of 5,
although it could be characterized crystallographically. Satisfactory
elemental analyses could not be obtained for this material, perhaps
because of its air sensitivity. Anal. Calcd for C50H80P4Pt: C, 60.04;
H, 8.06. Found: C, 58.32; H, 8.11. These results are consistent
with oxidation at both phosphorus centers: Anal. Calcd for
C50H80O2P4Pt: C, 58.18; H, 7.81. Mass spectroscopy was also
Method II. A slurry of NaOSiMe3 (13 mg, 0.11 mmol) in toluene
(0.5 mL) was added to a slurry of [Pt((R,R)-Me-Duphos)(Cl)-

Pt Duphos Terminal Phosphido Complexes
Organometallics, Vol. 25, No. 22, 2006 5445
consistent with oxidation. HRMS (m/z): calcd for C50H81P4PtO2
(MO2H)+, 1032.4849; found, 1032.4847. 31P{1H} NMR (21 °C,
THF-d8): δ 57.5 (broad), -56.7 (broad). See Table 1 for low-
temperature 31P NMR data. In addition to the three diastereomers
listed there, we consistently observed PHMe(Is) and a trace amount
of an unidentified phosphido complex (31P{1H} NMR (-50 °C,
THF-d8): δ 57.8 (apparent dd, J ) 114, 12), -102.9 (apparent dd,
J ) 114, 12, JPt-P ) 894)) in bulk samples of 5. We cannot exclude
the possibility that these peaks are due to a fourth diastereomer of
Pt((R,R)-Me-Duphos)(OH)(PMeIs). 31P{1H} NMR (21 °C,
THF-d8): δ 70.5 (dd, J ) 151, 8, JPt-P ) 1857), 49.4 (broad, JPt-P
∼3300), -44.9 (broad). At low temperature, a 1:1 mixture of
diastereomers was observed. 31P{1H} NMR (-20 °C, THF-d8): δ
70.5 (dd, J ) 152, 8, JPt-P ≈ 1860), overlapping with 70.4 (dd, J
≈ 150, 5), 52.5 (JPt-P ≈ 3174), 48.8 (JPt-P ≈ 3226), -41.9 (d, J )
151), -44.5 (d, J ≈ 150).
Addition of 1 Equiv More of PHMe(Is). The above mixture
was added to PHMe(Is) (18 mg, 0.07 mmol). It was transferred to
an NMR tube and monitored by 31P NMR spectroscopy. After 3 h
a precipitate was observed. Unreacted PHMe(Is) was a major
component of the mixture. The Pt(Duphos) species in solution were
Pt((R,R)-Me-Duphos)(PMeIs)2 (5; 61%), Pt((R,R)-Me-Duphos)-
(OH)(PMeIs) (24%), Pt((R,R)-Me-Duphos)(Cl)(PMeIs) (4; 6%), Pt-
((R,R)-Me-Duphos)(OSiMe3)(PMeIs) (3%), Pt((R,R)-Me-Duphos)-
(OSiMe3)2 (3%), and Pt((R,R)-Me-Duphos)(OH)(OSiMe3) (3%).
After 20 h a precipitate was observed. Unreacted PHMeIs was a
major component of the mixture. The Pt(Duphos) species in solution
were 5 (69%), Pt((R,R)-Me-Duphos)(OH)(PMeIs) (29%), and Pt-
((R,R)-Me-Duphos)(OSiMe3)(PMeIs) (2%).
Reaction of Pt((R,R)-Me-Duphos)(Cl)(PMeIs) with NaO-
SiMe3/PHMeIs. To a solution of Pt((R,R)-Me-Duphos)(Cl)(PMeIs)
(4; contaminated with ∼7% impurity assigned as Pt((R,R)-Me-
Duphos)(OH)(PMeIs); 55 mg, 0.07 mmol) in THF (0.2 mL) was
added a slurry of NaOSiMe3 (8 mg, 0.07 mmol) in 0.3 mL of THF.
The mixture was transferred to an NMR tube and monitored by
31P NMR spectroscopy; after 3 h, no reaction had occurred. The
mixture was added to PHMe(Is) (18 mg, 0.07 mmol), transferred
to an NMR tube, and monitored by 31P NMR spectroscopy. After
30 min the mixture was unchanged. After 20 h the mixture consisted
mainly of Pt((R,R)-Me-Duphos)(PMeIs)2 (5), along with unreacted
PHMe(Is) and Pt((R,R)-Me-Duphos)(OH)(PMeIs).
1
5; they could also simply result from an impurity. H NMR (21
°C, THF-d8): δ 7.82-7.74 (m, 2H, Ar), 7.54-7.48 (m, 2H, Ar),
6.92 (broad, 4H, Ar), 5.00 (broad, 4H, CH), 2.87-2.72 (m, 4H),
2.65-2.35 (broad, 2H), 2.28-2.10 (m, 2H), 2.10-1.70 (m, 6H),
1.62-1.54 (m, 12H, Me), 1.26-1.13 (overlapping m, 36H, CH3),
0.55 (dd, J ) 25, 12, 6H, CH3).
Intermediates and Impurities in the Formation of Phosphido
Complexes 4 and 5. To investigate the formation of complexes 4
and 5, we studied the reaction of the chloro complexes Pt((R,R)-
Me-Duphos)Cl2 and Pt((R,R)-Me-Duphos)(Cl)(PMeIs) (4) with
NaOSiMe3, followed by the addition of PHMe(Is). Several com-
plexes were observed by 31P NMR spectroscopy; NMR data and
tentative assignments are included below. To account for all the
observations, including the magnitude of the JPt-P coupling
constants, we have assigned some species as platinum hydroxides,
assuming that they form via Me3SiOH, which decomposes to water
and (Me3Si)2O, and/or from adventitious water. The complicated
nature of the reaction mixtures is consistent with the difficulty we
observed in isolating pure 4 or 5 by these routes.
Reaction of Pt((R,R)-Me-Duphos)Cl2 with 2 Equiv of NaO-
SiMe3. To a white slurry of Pt((R,R)-Me-Duphos)Cl2 (40 mg, 0.07
mmol) in THF (0.2 mL) was added a slurry of NaOSiMe3 (16 mg,
0.14 mmol, 2 equiv) in 0.3 mL of THF. The reaction mixture was
transferred to an NMR tube and monitored by 31P NMR spectros-
copy. After 10 min a white precipitate was still observed on the
bottom of the tube, and unreacted Pt((R,R)-Me-Duphos)Cl2 (12%
of the mixture by 31P NMR integration) was observed in the
solution. The major component (65%) of the solution was tentatively
assigned as Pt((R,R)-Me-Duphos)(Cl)(OSiMe3); 23% of the material
was another unsymmetrical Pt(Duphos) complex, perhaps Pt((R,R)-
Me-Duphos)(OH)(OSiMe3).
[Pt((R,R)-Me-Duphos)(Ph)(PHMe(Is))][BF4] (6). Method I. To
a stirred solution of Pt((R,R)-Me-Duphos)(Ph)(PMeIs) (1; 64 mg,
0.08 mmol) in Et2O (10 mL) was added HBF4‚Me2O (12 mg, 0.085
mmol). A white precipitate formed immediately. After it settled,
the solvent was removed with a pipet and the precipitate was washed
with Et2O (3 × 5 mL). The precipitate was dried under vacuum,
yielding 55 mg (75%) of white powder. The 31P NMR spectrum is
reported for a mixture of two diastereomers a and b, whose ratio
varied over time (ratio a:b ) 5:1 after 1 h, 14:1 after 1 day).
Pt((R,R)-Me-Duphos)(Cl)(OSiMe3). 31P{1H} NMR (21 °C,
THF): δ 65.6 (d, J ) 7, JPt-P ) 3801), 55.5 (d, J ) 7, JPt-P
)
Anal. Calcd for C40H60P3PtBF4: C, 52.47; H, 6.60. Found: C,
52.09; H, 6.66. 31P{1H} NMR (CD2Cl2): diastereomer a, δ 63.1
(dd, J ) 372, 8, JPt-P ) 2623), 62.8 (dd, J ) 18, 8, JPt-P ) 1643),
-62.6 (dd, J ) 372, 18, JPt-P ) 2513); diastereomer b, δ 61.4
(dd, J ) 376, 6, JPt-P ) 2618), 67.6 (m, JPt-P ) 1691), -55.2 (dd,
3289).
Pt((R,R)-Me-Duphos)(OH)(OSiMe3). 31P{1H} NMR (21 °C,
THF): δ 55.9 (d, J ) 10, JPt-P ) 3635), 54.4 (d, J ) 10, JPt-P
3115).
)
1
J ) 376, 18, JPt-P ) 2472). Selected H NMR data (CD2Cl2, all
Addition of 1 Equiv of PHMe(Is). The above mixture was
added to PHMe(Is) (18 mg, 0.07 mmol). The color changed to
orange immediately. It was transferred to an NMR tube and
monitored by 31P NMR spectroscopy. After 10 min precipitate was
still observed. Unreacted PHMe(Is) was a major component of the
mixture. The Pt(Duphos) species in solution were Pt((R,R)-Me-
Duphos)(Cl)(PMeIs) (4; 55%), Pt((R,R)-Me-Duphos)(OSiMe3)-
(PMeIs) (21%), Pt((R,R)-Me-Duphos)(OH)(OSiMe3) (13%), Pt-
((R,R)-Me-Duphos)(Cl)(OSiMe3) (6%), and two other unidentified
species, one possibly Pt((R,R)-Me-Duphos)(OH)(PMeIs) (3%) and
the other Pt((R,R)-Me-Duphos)X2 (X ) OSiMe3 or OH) (1%). After
20 h, PHMe(Is) was entirely consumed, and the Pt(Duphos) species
in solution were 4 (50%), Pt((R,R)-Me-Duphos)(OH)(PMeIs) (25%),
Pt((R,R)-Me-Duphos)(OH)(OSiMe3) (10%), Pt((R,R)-Me-Duphos)-
(OSiMe3)2 (10%), Pt((R,R)-Me-Duphos)(Cl)(OSiMe3) (3%), and Pt-
((R,R)-Me-Duphos)(OSiMe3)(PMeIs) (2%).
for the major diastereomer a unless indicated): δ 7.24 (dm, J )
355, P-H, b), 7.21 (d, J ) 4, 2H, Is), 6.79 (dm, J ) 361, P-H),
1.45 (dd, J ) 19, 7, 3H, CH3, Duphos), 1.36 (dd, J ) 18, 8, 3H,
CH3, Duphos), 1.35 (d, J ) 7, 6H, 2CH3 Is), 1.29 (d, J ) 7, 6H,
2CH3, Is), 1.26 (d, J ) 7, 6H, 2CH3, Is), 1.08 (ddd, J ) 7, 4, 2,
JPt-H ) 38, P-CH3), 0.87 (dd, J ) 17, 8, 3H, CH3, Duphos), 0.74
(m, 1H, CH, Duphos), 0.69 (dd, J ) 16, 7, 3H, CH3, Duphos).
Method II. To a stirred solution of Pt((R,R)-Me-Duphos)(Ph)-
(Cl) (140 mg, 0.22 mmol) and PHMe(Is) (21 mg, 0.22 mmol) in
THF (20 mL) was added AgOTf (57.1 mg, 0.22 mmol) dissolved
in THF (5 mL). Immediate formation of AgCl was observed, and
the reaction mixture was stirred vigorously at room temperature
for 30 min and then filtered through Celite and concentrated under
vacuum. Petroleum ether was added to the viscous residue, and
cooling of this solution to -25 °C gave 167 mg (77%) of an off-
white solid, 6-OTf.
[Pt((R,R)-i-Pr-Duphos)(Ph)(PHMe(Is))][BF4] (7). A solution
of HBF4‚Me2O (11.6 mg, 0.086 mmol) in 10 mL of Et2O was added
to a yellow solution of Pt((R,R)-i-Pr-Duphos)(Ph)(PMeIs) (2; 74
mg, 0.08 mmol) in 10 mL of Et2O. A white precipitate formed
Pt((R,R)-Me-Duphos)(OSiMe3)(PMeIs). 31P{1H} NMR (21 °C,
THF): δ 66.8 (dd, J ) 136, 10, JPt-P ) 1620), 43.5 (JPt-P ) 3815),
-44.8 (broad d, J ) 136, JPt-P ≈ 800).
Pt((R,R)-Me-Duphos)X2 (X ) OSiMe3, OH). 31P{1H} NMR
(21 °C, THF): δ 54.7 (JPt-P ) 3545).

5446 Organometallics, Vol. 25, No. 22, 2006
Scriban et al.
immediately. The solvent was removed with a pipet, and the
precipitate was washed with Et2O (3 portions of 5 mL) and then
dried under vacuum, yielding 55 mg (67%) of the product as a
1.3:1 mixture of the two diastereomers a and b. Recrystallization
from THF/petroleum ether yielded crystals of diastereomer a, as
shown by NMR spectroscopy in CD2Cl2. The solvent was removed
from this sample under vacuum to give a solid which was analyzed
correctly for a CD2Cl2 solvate.
12.5 µL, 0.12 mmol). An off-white slurry formed immediately, and
the solvent was removed under vacuum. Petroleum ether (1 mL) was
added to the viscous residue, and an off-white precipitate formed.
The solvent was removed with a pipet, and the precipitate was
washed with petroleum ether (3 × 2 mL). The precipitate was dried
1
under vacuum, yielding 76 mg (87%) of white powder. The H
NMR spectrum is reported as a mixture of two diastereomers (ratio
a:b ) 2.3:1 based on integration of P-H signals) unless otherwise
indicated. Because the starting material was not pure, we could
not obtain the cation in pure form (∼5% of unidentified impurities).
Anal. Calcd for C48H76P3PtBF4‚CD2Cl2: C, 52.79; H, 6.87.
Found: C, 52.74; H, 7.16. From comparison of the NMR spectra
of the 1.3:1 mixture and pure diastereomer a, assignments of most
of the NMR signals could be made. 31P{1H} NMR (CD2Cl2):
diastereomer a, δ 58.4 (dd, J ) 372, 6, JPt-P ) 2681), 57.3 (dd, J
) 17, 6, JPt-P ) 1656), -66.1 (dd, J ) 372, 17, JPt-P ) 2510);
diastereomer b, δ 57.1 (dd, J ) 377, 5, JPt-P ) 2687), 53.7 (dd, J
) 15, 5, JPt-P ) 1631), -60.3 (dd, J ) 377, 15, JPt-P ) 2481). 1H
NMR (diastereomer a, CD2Cl2): δ 7.85-7.80 (m, 1H, Ar), 7.77-
7.74 (m, 1H, Ar), 7.74-7.66 (m, 2H, Ar), 7.65-7.50 (t, J ) 6,
JPt-H ) 41, 1H, Ar), 7.31-7.24 (m, 3H, Ar), 7.18 (d, J ) 3, 2H,
Ar), 7.12-7.02 (m, 1H, Ar), 6.76 (dm, J ) 358, 1H, PH), 3.52-
3.50 (m, 2H, i-Pr CH), 2.94-2.89 (m, 1H), 2.74-2.51 (m, 5H),
2.09-1.83 (m, 5H), 1.71-1.66 (m, 1H), 1.60-1.44 (m, 5H), 1.33-
1.28 (overlapping m, 15H), 1.23 (overlapping d, J ) 7, 6H), 1.12-
1.07 (m, 3H, P-Me), 1.03 (d, J ) 6, 3H), 0.76 (d, J ) 6, 3H),
0.64 (d, J ) 6, 3H), 0.56 (d, J ) 6, 3H), 0.30 (d, J ) 6, 3H), 0.18
(d, J ) 6, 3H). 1H NMR (selected signals for diastereomer b, CD2-
Cl2; in some cases, overlap with signals from a precluded
assignment): δ 7.93-7.91 (m, 1H, Ar), 7.82-7.72 (m, overlapping
signals from major diastereomer, 2H, Ar), 7.01 (broad, 2H, Ar),
6.86-6.84 (m, 2H, Ar), 6.74-6.71 (m, 1H, Ar), 6.44 (dm, J )
372, 1H, PH), 1.36-1.28 (m, overlapping signals from major
diastereomer, 9H), 1.23 (d, J ) 7, 6H), 1.14-1.08 (m, overlapping
signals from major diastereomer, 9H), 0.99 (d, J ) 7, 3H), 0.89
(d, J ) 6, 3H), 0.87 (d, J ) 6, 3H), 0.78 (d, J ) 7, 3H), 0.71 (d,
J ) 6, 3H), 0.70 (d, J ) 6, 3H), 0.58 (d, J ) 6, 3H).
Method II. A slurry of AgBF4 (39 mg, 0.2 mmol) in CH3CN
(0.5 mL) was added to a slurry of Pt((R,R)-Me-Duphos)Cl2
(115 mg, 0.2 mmol) in CH3CN (1 mL), with stirring. A white
precipitate formed immediately. The mixture was filtered through
Celite and concentrated under vacuum. The 31P NMR (CH3CN)
spectrum of the solution showed the presence of ∼10% of impurities
(unreacted Pt((R,R)-Me-Duphos)Cl2 and [Pt((R,R)-Me-Duphos)-
(NCMe)2][BF4]2). The solvent was removed under vacuum, and
the residue was washed with petroleum ether (3 × 0.2 mL) and
dried under vacuum. Recrystallization from THF/petroleum ether
yielded 110 mg (76%) of white powder, which was used in the
next step without further purification.
[Pt((R,R)-Me-Duphos)(Cl)(NCMe)][BF4]. 31P{1H} NMR (CD2-
Cl2): δ 70.9 (JPt-P ) 3307), 64.5 (JPt-P ) 3664). 31P{1H} NMR
(CH3CN): δ 70.7 (JPt-P ) 3300), 64.4 (JPt-P ) 3645).
[Pt((R,R)-Me-Duphos)(NCMe)2][BF4]2. This complex was gen-
erated independently, using 2 equiv of AgBF4. 31P{1H} NMR (CD2-
Cl2): δ 67.3 (JPt-P ) 3478). 31P{1H} NMR (CH3CN): δ 67.0 (JPt-P
) 3495).
Pt((R,R)-Me-Duphos)Cl2. 31P{1H} NMR (CD2Cl2): δ 69.4
(JPt-P ) 3557). 31P{1H} NMR (CH3CN): δ 68.1 (JPt-P ) 3511).
A solution of PHMe(Is) (41.5 mg, 0.165 mmol) in CH2Cl2
(0.5 mL) was added to a solution of impure [Pt((R,R)-Me-Duphos)-
(Cl)(NCMe)][BF4] (110 mg, 0.165 mmol) in CH2Cl2 (1 mL). The
solvent was removed under vacuum, and the white residue was
washed with petroleum ether (3 × 0.5 mL) and dried under vacuum,
yielding 105 mg (73%) of white powder. CH2Cl2 (0.2 mL) was
added to the powder, and crystals suitable for X-ray crystallography
were formed on the walls of the vial. The solvent was removed
with a pipet, and the crystals were dried under vacuum. The
compound was found to cocrystallize with CH2Cl2 by X-ray
crystallography and elemental analyses. Two diastereomers were
observed (ratio a:b ) 1:1.4 on the basis of integration of P-H
signals in the 1H NMR spectrum). Impurities (Pt((R,R)-Me-
Duphos)Cl2 and an unidentified Pt-secondary phosphine species
(perhaps (Pt((R,R)-Me-Duphos)(PHMe(Is))(NCMe)][BF4]2, ∼5%))
were still observed in the 31P NMR spectrum of the bulk material.
Anal. Calcd. for BC34F4H55ClP3Pt: C, 46.72; H, 6.34. Calcd for
BC34F4H55ClP3Pt‚0.4CH2Cl2: C, 45.50; H, 6.19. Found: C, 45.25;
H, 5.79. HRMS (m/z): calcd for C34ClH55P3Pt+ (M+), 785.2832;
found, 785.2837. 31P{1H} NMR (CD2Cl2): diastereomer a, δ 78.9
(dd, J ) 377, 3, JPt-P ) 2380), 62.9 (dd, J ) 18, 3, JPt-P ) 3282),
-60.3 (dd, J ) 377, 18, JPt-P ) 2227); diastereomer b, δ 78.8
(dd, J ) 379, 3, JPt-P ) 2356), 65.4 (d, J ) 17, JPt-P ) 3312),
-53.5 (dd, J ) 379, 17, JPt-P ) 2230). 1H NMR (CD2Cl2): δ 7.84-
7.70 (m, 3H), 7.70-7.64 (m, 1H), 7.22 (d, J ) 4, 2H, Is, a), 7.18
(d, J ) 4, 2H, Is, b), 6.44 (dm, J ) 362, P-H, a), 6.29 (dm, J )
371, P-H, b), 3.86-3.76 (m, 2H, a), 3.68-3.62 (m, 2H, b), 3.44-
3.31 (m, 1H), 3.15-2.76 (m, 3H), 2.58-2.26 (m, 4H), 2.26-2.12
(m, 1H), 2.06-1.98 (m, 3H, Me), 1.96-1.68 (m, 4H), 1.54 (dd, J
) 20, 7, 3H, Me, a), 1.58-1.23 (overlapping m, 21H, Me), 1.05
(dd, J ) 17, 7, 3H, b), 0.96-0.82 (m, 3H, Me), 0.69 (dd, J ) 17,
7, 3H, a), 0.66 (dd, J ) 20, 8, 3H, Me, b). NMR data for the
unidentified impurity: 31P{1H} NMR (CD2Cl2) δ 80.3 (d, J ) 380),
67.1 (d, J ) 17), -82.8 (dd, J ) 377, 17).
[Pt((R,R)-Me-Duphos)(I)(PH(Me)(Is))][BF4] (8). To a stirred
solution of Pt((R,R)-Me-Duphos)(I)(PMeIs) (88 mg, 0.1 mmol) in
Et2O (10 mL) was added HBF4‚Me2O (16 mg, 12.5 µL, 0.12 mmol).
An off-white precipitate formed immediately. After it settled, the
solvent was removed with a pipet and the precipitate was washed
with Et2O (3 × 5 mL). The precipitate was dried under vacuum,
yielding 85 mg (88%) of off-white powder, which was recrystallized
from CH2Cl2/Et2O for elemental analyses. Note: this and the related
cationic secondary phosphine complexes tended to cocrystallize with
these solvents, which were readily lost on standing. In this case, a
1
trace of CH2Cl2 was observed by H NMR spectroscopy in the
analytical sample. Anal. Calcd for BC34F4H55IP3Pt: C, 42.30; H,
5.74. Anal. Calcd for BC34F4H55IP3Pt‚0.05CH2Cl2 (observed by 1H
NMR (CD2Cl2)): C, 42.17; H, 5.73. Found: C, 41.77; H, 5.80.
The NMR spectra are reported for a mixture of two diastereomers
(ratio a:b ) 3:1 on the basis of integration of the 1H NMR
spectrum). 31P{1H} NMR (CD2Cl2): diastereomer a, δ 74.8 (d, J
) 374, JPt-P ) 2321), 65.0 (d, J ) 18, JPt-P ) 3102), -72.0 (dd,
J ) 374, 18, JPt-P ) 2213); diastereomer b, δ 73.4 (d, J ) 383,
JPt-P ) 2289), 72.0 (d, J ) 15, JPt-P ) 3175), -65.8 (dd, J ) 383,
15, JPt-P ) 2164). 1H NMR (CD2Cl2): δ 7.92-7.76 (m, 3H), 7.73
(tm, J ) 7, 1H), 7.22 (d, J ) 4, 2H, Is, a), 7.16 (d, J ) 4, 2H, Is,
b), 6.67 (dm, J ) 384, P-H, b), 6.43 (dm, J ) 343, P-H, a),
4.06-3.93 (m, 1H, a), 3.88-3.78 (m, 1H), 3.62-3.54 (m, 1H, b),
3.12-2.79 (m, 2H), 2.63-2.23 (m, 5H), 2.23-2.08 (m, 1H, a),
2.08-1.78 (m, 2H), 1.78-1.66 (m, 1H, b), 1.54 (d, J ) 7, 3H, a),
1.53 (dd, J ) 20, 7, 3H, a, overlapping 3H, b), 1.43-1.33 (m,
4H), 1.33-1.24 (m, 18H), 1.12 (dd, J ) 7, 3, 3H, b), 1.09 (d, J )
7, 3H, b), 0.90-0.82 (m, 3H), 0.69 (dd, J ) 17, 7, 3H, a).
[Pt((R,R)-Me-Duphos)(Cl)(PHMe(Is))][BF4] (9). Method I. To
a stirred yellow slurry of Pt((R,R)-Me-Duphos)(Cl)(PMeIs) (4; 79
mg, 0.1 mmol) in Et2O (2 mL) was added HBF4‚Me2O (26 mg,
[Pt((R,R)-Me-Duphos)(PHMe(Is))2][BF4]2 (10). To a stirred
solution of Pt((R,R)-Me-Duphos)(PMeIs)2 containing ∼30% of

Pt Duphos Terminal Phosphido Complexes
Organometallics, Vol. 25, No. 22, 2006 5447
chloro complex 4 impurity (100 mg, 0.1 mmol) in Et2O (10 mL)
was added HBF4‚Me2O (32 mg, 25 µL, 0.24 mmol). A white precip-
itate formed immediately. After it settled, the solvent was removed
with a pipet and the precipitate was washed with Et2O (3 × 5 mL).
The precipitate was dried under vacuum, yielding 115 mg (98%)
of white powder, whose 31P NMR spectrum showed that it consisted
of a mixture of dication 10 (∼70%) and cation 9 (∼30%).
Recrystallization from CH2Cl2/Et2O yielded white crystals of a
methylene chloride solvate of 10 as a mixture of three diastereomers
JPt-C ) 33, CH), 36.3 (JPt-C ) 35, CH2), 34.6 (broad two-line
pattern with apparent J ) 7, CH2), 16.8 (JPt-C ) 35, Me), 13.5
(Me).
Pt((R,R)-Me-Duphos)(Cl)(P(O)MeIs) (11). Method I. To a
yellow solution of impure Pt((R,R)-Me-Duphos)(Cl)(PMeIs) (4; 70
mg, 0.09 mmol) in 0.5 mL of THF-d8 in an NMR tube fitted with
a rubber septum was added H2O2 (30% in H2O, 20 µL, 0.18 mmol),
with a microliter syringe. The reaction mixture became colorless,
and gas evolved. 31P NMR spectroscopy indicated the formation
of 11. The solvent was removed under vacuum, and the white
residue was washed with ether (3 × 0.5 mL). Drying the precipitate
yielded 68 mg (94%) of white powder as a mixture of two
diastereomers (ratio a:b ) 10.8:1). Recrystallization from CD2Cl2/
ether at 5 °C gave crystals enriched in diastereomer a (ratio a:b )
28.1:1).
Method II. A yellow solution of Pt((R,R)-Me-Duphos)(Cl)-
(PMeIs) (4; 50 mg, 0.06 mmol) in 0.5 mL of toluene-d8 in a capped,
Parafilm-wrapped NMR tube became colorless after 2 months in
the air. Crystals suitable for X-ray crystallography formed on the
walls of the NMR tube.
1
(ratio a:b:c ) 3.7:1.2:1, from H NMR integration). Anal. Calcd
for C50H82P4PtB2F8: C, 51.08; H, 7.03. Anal. Calcd. for C50H82P4-
PtB2F8‚CH2Cl2: C, 48.59; H, 6.72. Found: C, 48.60; H, 6.97. The
1
cocrystallized solvent was observed by H NMR spectroscopy in
CD2Cl2. HRMS (m/z): calcd for C50H83P4Pt (MH)3+, 1001.5072;
found, 1001.4654. 31P{1H} NMR (CD2Cl4): diastereomer a, δ 70.7
(AA′XX′ pattern, JAX ) 297, JAX′ ) -23, JAA′ ) 31, JXX′ ) 0,
JPt-P ) 2188), -71.6 (AA′XX′ pattern, JAX ) 297, JAX′ ) -23,
JAA′ ) 31, JXX′ ) 0, JPt-P ) 2202); other diastereomers, δ 77.9
(broad d, J ) 294), 68.5 (apparent dd, J ) 296, 23, JPt-P ) 2150),
1
-67.9 (broad), -69.4 (broad). Selected H NMR (CD2Cl4) sig-
HRMS (m/z): calcd for C34H54ClOP3Pt+ (M+), 801.2737; found,
801.2780. Anal. Calcd for C34H54OClP3Pt: C, 50.90; H, 6.78. Calcd
for C34H54OClP3Pt‚0.5CD2Cl2 (the solvent of recrystallization): C,
49.00; H, 6.44. Found: C, 48.78; H, 6.66. 31P{1H} NMR (CD2-
nals: 8.00-7.80 (m, 4H, Ar), 7.36-7.30 (broad, 4H, Is, a), 7.30-
7.24 (broad m, 4H, Is, b), 7.24-7.20 (broad m, 4H, Is, c), 7.18
(broad dm, JP-H ) 383, 2H, P-H, b), 7.12 (broad dm, JP-H
)
383, 2H, P-H, a), 6.72 (broad dm, JP-H ) 388, 2H, P-H, c), 3.62-
3.53 (m, 2H), 3.44-3.20 (m, 2H), 3.15-2.96 (m, 2H), 2.80-2.62
(m, 2H), 2.46-2.30 (m, 4H), 2.28-1.90 (m, 4H), 1.70-1.28
(overlapping m, ∼51H, Me), 1.02 (dd, J ) 18, 7, 3H, Me, b), 0.75
(dd, J ) 17, 7, 3H, Me, a), 0.62 (dd, J ) 18, 7, 3H, Me, c).
Cl2): diastereomer a, δ 64.9 (collapsed32 dd, J ) 431, 9, JPt-P
)
1452), 64.7 (collapsed32 dd, J ) 431, 16, JPt-P ) 2796), 56.0 (dd,
J ) 16, 9, JPt-P ) 3918); diastereomer b, δ 65.7 (dd, J ) 432, 9),
1
60.8 (dd, J ) 432, 17), 60.1 (dd, J ) 16, 9, JPt-P ) 3913). H
NMR (CD2Cl2): δ 7.70-7.65 (m, 1H, Ar), 7.62-7.54 (m, 3H, Ar),
7.05 (2H, Ar), 4.80-4.68 (m, 2H), 3.20-3.08 (m, 1H), 3.08-2.90
(m, 2H), 2.90-2.80 (m, 1H), 2.55-2.30 (m, 4H), 2.15-2.03 (m,
2H), 2.03-1.90 (m, 4H), 1.75-1.61 (m, 2H), 1.503 (dd, J ) 20,
7, 3H, Me), 1.495 (dd, J ) 18, 7, 3H, Me), 1.23 (d, J ) 7, 6H,
Me), 1.204 (d, J ) 7, 6H, Me), 1.20 (d, J ) 7, 6H, Me), 0.86 (dd,
J ) 16, 8, 3H, Me), 0.73 (dd, J ) 16, 8, 3H, Me). 13C{1H} NMR
(CD2Cl2): δ 152.8 (quat), 149.6 (quat), 139.3 (d, J ) 24, quat),
138.2 (d, J ) 27, quat), 133.3-133.0 (m, quat), 132.55 (Ar), 132.45
(Ar), 132.0 (d, J ) 6, Ar), 131.4 (d, J ) 3, Ar), 121.9 (apparent t,
J ) 4), 46.0 (d, J ) 39), 41.9 (d, J ) 16), 41.7 (d, J ) 14), 38.0,
37.5, 37.0, 36.7 (d, J ) 14), 36.5 (d, J ) 15), 34.7 (d, J ) 6), 34.4,
30.3, 26.7 (2Me, Is), 25.1 (2Me, Is), 24.0 (2Me, Is), 16.60 (d, J )
5), 16.56 (d, J ) 4), 16.3 (d, J ) 4), 14.6, 13.7 (d, J ) 2).
Pt((R,R)-Me-Duphos)(P(O)MeIs)2 (12). To a yellow solution
of bis(phosphido) complex 5 containing ∼20% of chloro complex
4 and Pt((R,R)-Me-Duphos)(OSiMe3)(PMeIs) as impurities (49 mg,
0.049 mmol) in 0.5 mL of toluene in an NMR tube fitted with a
rubber septum was added H2O2 (30% in H2O, 28 µL, 0.25 mmol),
with a microliter syringe. The reaction mixture became colorless,
and gas evolved. 31P NMR spectroscopy indicated disappearance
of the starting material. The solvent was removed under vacuum,
and the white residue was washed with ether (3 × 0.5 mL). Drying
the precipitate yielded 45 mg (89%) of white powder. Recrystal-
lization from CD2Cl2/ether at 5 °C gave 35 mg (69%) of white
crystals consisting of a 1:1 mixture of diastereomers a and b.
HRMS (m/z): calcd for C50H81O2P4Pt+ (MH+), 1031.4814;
found, 1031.4810. Anal. Calcd for C50H80O2P4Pt: C, 58.18; H, 7.81.
Calcd for C50H80P4PtO2‚0.3CD2Cl2 (recrystallization solvent): C,
57.12; H, 7.68. Found: C, 57.21; H, 6.98. 31P{1H} NMR (CD2-
Cl2): δ 60.6 (dm, J ) 365, JPt-P ) 1656), 51.3 (dm, J ) 360,
JPt-P ) 1864), 50.4 (dm, J ) 362, JPt-P ) 2954), 48.1 (dm, J )
[Pt((R,R)-Me-Duphos)(PHMe(Is))2][OTf]2 (10-OTf). A solu-
tion of PHMe(Is) (69 mg, 0.28 mmol) in CH2Cl2 (0.5 mL) was
added to a solution of Pt((R,R)-Me-Duphos)(OTf)2 (110 mg, 0.138
mmol, see below) in CH2Cl2 (1 mL). The solvent was removed
under vacuum, and THF (0.3 mL) was added to the mixture. After
a few minutes white crystals started to precipitate. The solution
was removed with a pipet, and the crystals were washed with THF
(3 × 0.2 mL) and dried under vacuum, yielding 75 mg (43%) of
white crystals as a mixture of 3 diastereomers (ratio a:b:c ) 3.8:
1:1.1).
31P{1H} NMR (CD2Cl2): diastereomer a, δ 69.9 (AA′XX′
pattern, JAX ) 298, JAX′ ) -24, JAA′ ) 32, JXX′ ) 0, JPt-P ) 2188),
-71.6 (AA′XX′ pattern, JAX ) 298, JAX′ ) -24, JAA′ ) 32, JXX′
) 0, JPt-P ) 2200); diastereomer b, δ 78.2 (dd, J ) 289, 19, JPt-P
) 2275), -68.0 (broad d, J ) 310, JPt-P ) 2237), diastereomer c,
δ 68.1 (apparent dd, J ) 296, 24, JPt-P ) 2158), -70.9 (broad d,
J ) 287, JPt-P ) 2160).
Pt((R,R)-Me-Duphos)(OTf)2. To a slurry of Pt((R,R)-Me-
Duphos)Cl2 (115 mg, 0.2 mmol) in CH2Cl2 (1 mL) was added a
slurry of AgOTf (103 mg, 0.4 mmol) in CH2Cl2 (1 mL). A white
precipitate formed immediately. The slurry was filtered through
Celite, and the filtrate was concentrated under vacuum. The 31P
NMR spectrum of the filtrate indicated only ∼65% conversion. A
slurry of AgOTf (55 mg, 0.2 mmol) in CH2Cl2 (1 mL) was added
to the filtrate. A gray precipitate was observed after 15 h. The
mixture was filtered through Celite, and the filtrate was concentrated
under vacuum. The white residue was washed with petroleum ether
(3 × 0.5 mL) and dried under vacuum, yielding 120 mg (75% yield)
of white powder.
Anal. Calcd for C20H28F6O6P2PtS2: C, 30.04; H, 3.53. Found:
C, 30.21; H, 3.65. 31P{1H} NMR (CD2Cl2): δ 65.9 (JPt-P ) 4038).
1H NMR (CD2Cl2): δ 7.85-7.70 (m, 4H, Ar), 3.75-3.55 (m, 2H),
2.82-2.64 (m, 2H), 2.50-2.25 (m, 4H), 2.10-1.90 (m, 2H), 1.88-
1.70 (m, 2H), 1.52 (dd, J ) 20, 7, 6H, Me), 0.87 (dd, J ) 18, 7,
6H, Me). 13C{1H} NMR (CD2Cl2): δ 137.6 (dd, J ) 60, 21, quat),
134.2-134.1 (m, Ar), 133.4-132.1 (m, Ar), 120.2 (q, JC-F ) 319,
OSO2CF3), 40.4 (d, J ) 40, JPt-C ) 30, CH), 36.6 (d, J ) 38,
(32) The 31P NMR signals for the phosphido oxide and one of the Duphos
P atoms were accidentally coincident in this diastereomer, resulting in a
single overlapping signal. The expected large JPP22 was observed in the Pt
satellites. For similar observations in Pt-phosphine complexes, see: (a)
Sperline, R. P.; Beaulieu, W. B.; Roundhill, D. M. Inorg. Chem. 1978, 17,
2032-2035. (b) Brown, M. P.; Fisher, J. R.; Puddephatt, R. J.; Seddon, K.
R. Inorg. Chem. 1979, 18, 2808-2813. (c) Gukathasan, R. R.; Morris, R.
H.; Walker, A. Can. J. Chem. 1983, 61, 2490-2492.

5448 Organometallics, Vol. 25, No. 22, 2006
Scriban et al.
359, JPt-P ) 3185). 1H NMR (CD2Cl2): δ 7.78-7.73 (m, 1H, Ar),
7.64-7.57 (m, 1H, Ar), 7.56-7.48 (m, 2H, Ar), 7.09 (1H, Ar),
7.08 (1H, Ar), 7.04 (1H, Ar), 6.95 (1H, Ar), 5.64-5.53 (m, 1H),
5.38-5.27 (m, 1H), 4.56-4.47 (m, 1H), 4.12-4.05 (m, 1H), 3.32-
3.20 (m, 1H), 3.08-2.97 (m, 1H), 2.90-2.78 (m, 2H), 2.65-2.51
(m, 1H), 2.48-2.30 (m, 3H), 2.30-2.22 (m, 2H), 2.22-2.14 (m,
3H), 2.01-1.88 (m, 3H, Me), 1.79 (dd, J ) 18, 7, 3H, Me), 1.71-
1.62 (overlapping m, 4H, Me + 1H), 1.58 (dd, J ) 18, 7, 3H,
Me), 1.45 (d, J ) 6, 3H, Me), 1.28-1.25 (overlapping m, 9H, Me),
1.23-1.18 (overlapping m, 12H, Me), 1.145 (d, J ) 7, 3H, Me),
1.141 (d, J ) 7, 3H, Me), 1.07 (d, J ) 7, 3H, Me), 1.02 (d, J ) 7,
3H, Me), 0.72 (dd, J ) 16, 7, 3H, Me), 0.37 (dd, J ) 15, 7, 3H,
Me).
Reaction of 1 with [Pd(allyl)Cl]2. Formation of PMe(Is)(allyl)
(13). To a yellow solution of phosphido complex 1 (49.7 mg, 0.06
mmol) in 0.3 mL of toluene was added [Pd(allyl)Cl]2 (11 mg, 0.03
mmol) in 0.2 mL of toluene. The reaction mixture turned brown
immediately. It was transferred to an NMR tube and monitored by
31P NMR spectroscopy. Pt((R,R)-Me-Duphos)(Ph)(Cl) (δ 67.6 (JPt-P
) 1618), 55.7 (JPt-P ) 3892)) was the major (>90%) Pt-Duphos-
containing species. Some unidentified materials (δ 58.8, 57.7,
-37.5, -51.7), PMeIs(allyl) (δ -48.6), and multiplets assigned to
Pd-PMeIs(allyl) species (δ 25.6-24.8, -9.1 to -9.5, -10.0 to
-10.4, -13.2 to -13.6, -13.9 to -14.4, -15.9 to -16.4, -16.8
to -17.2) were observed.
Determination of ee. The tertiary phosphine (8 mg, 0.027 mmol)
was dissolved in 0.5 mL of C6D6. This solution was added to (S)-
{Pd[NMe2CH(Me)C6H4](µ-Cl)}2 (8 mg, 0.014 mmol), and the
mixture was transferred to an NMR tube. The ee was determined
by integration of the 31P NMR signals of the diastereomers. 31P-
{1H} NMR (C6D6): δ 9.6, 9.1; ratio 1:3, 51% ee.
Reaction of 1 with Pd(P(o-Tol)3)2. Generation of Pt((R,R)-
Me-Duphos)(Ph)(µ-PMe(Is))(Pd(P(o-Tol)3)) (14). Complex 1
(83 mg, 0.1 mmol) in toluene (1 mL) was added to a slurry of
Pd(P(o-Tol)3)2 (72 mg, 0.1 mmol) in toluene (1 mL). The mixture
turned brown immediately, but unreacted Pd(P(o-Tol)3)2 was still
observed as a light-colored precipitate. A sample of the reaction
mixture was transferred into an NMR tube and monitored by 31P
NMR spectroscopy. After 10 min, complex 14 (as a 1:1 mixture
of two diastereomers a and b) and P(o-Tol)3 were the major
components of the mixture, along with unreacted 1. After 20 h, a
light-colored precipitate was still present, but Pd(P(o-Tol)3)2 was
observed in solution by 31P NMR spectroscopy. The ratio 14:P(o-
Tol)3:1:Pd(P(o-Tol)3)2 was 22.2:14.0:2.6:1; standing for 4 days
caused small changes in the ratio, but the reaction did not proceed
to completion.
The LRMS spectrum of this mixture showed peaks corresponding
to PdP(o-Tol)3 (m/z 411), Pd(P(o-Tol)3)2 (m/z 715.3), Pt(Me-
Duphos)(Ph) (m/z 579.4), and Pt(Me-Duphos)(Ph)(P(O)(Me)(Is))
(m/z 844.4). The following NMR spectra are reported for the
mixture of two diastereomers.
A solution of dppe (48 mg, 0.12 mmol) in 0.1 mL of toluene
was added to the reaction mixture. Pt(Me-Duphos)(Ph)(Cl), Pd-
(dppe)2 (δ 32.0), dppe (δ -11.6), and PMeIs(allyl) (δ -49.1) were
observed in the mixture. The solvent was removed under vacuum,
and a 9:1 petroleum ether-THF mixture (0.5 mL) was added to
the residue. Pt((R,R)-Me-Duphos)(Ph)(Cl) was removed from the
reaction mixture on a silica column (5 cm height, 0.6 cm diameter),
using a 9:1 petroleum ether-THF mixture as eluent; the Pt complex
did not elute. The solvent was removed under vacuum, and 39 mg
of an off-yellow powder was obtained. The mixture consisted of
Pd(dppe)2, dppe, and PMeIs(allyl). Chromatography on a silica
column (5 cm height, 0.6 cm diameter), using petroleum ether
eluent, gave a solution of the allylphosphine (Pd(dppe)2 and dppe
did not elute). The solvent was removed under vacuum, and 12
mg (71% yield) of a colorless oil was obtained. The tertiary
phosphine was dissolved in 0.5 mL of C6D6 for spectroscopic
characterization, which showed it was 94% pure (by 31P NMR).
Both the protonated phosphine and the protonated phosphine
oxide were observed by mass spectroscopy. HRMS (m/z): calcd
for C19H32P+(MH+), 291.2242; found, 291.2237. HRMS (m/z):
calcd for C19H32OP+ (MOH+), 307.2191; found, 307.2196. 31P-
Pt((R,R)-Me-Duphos)(Ph)(µ-PMe(Is))(Pd(P(o-Tol)3)) (14). 31P-
{1H} NMR (toluene): δ 57.0 (dd, J ) 244, 7, JPt-P ) 1839), 55.564
(dd, J ) 248, 7, JPt-P ) 1845), 55.560 (JPt-P ) 1864), 52.6 (JPt-P
) 1819), 0.2 (d, J ) 234), -0.7 (d, J ) 230), -35.0 (overlapping
dd, J ≈ 248, 234, JPt-P ) 1592), -42.6 (overlapping dd, J ≈ 244,
230, JPt-P ) 1507).
Pd(P(o-Tol)3)2. 31P{1H} NMR (toluene): δ -6.4.
P(o-Tol)3. 31P{1H} NMR (toluene): δ -28.5.
X-ray Crystallography. Crystallographic data are collected in
Table 3. All diffraction data were collected on Bruker diffracto-
meters equipped with APEX CCD detectors at the temperatures
shown. All data were corrected for absorption using empirical
(multiscan) methods. Space group assignments were unambiguous
for chiral molecules. All structures were refined using anisotropic
thermal parameters for non-hydrogen atoms, and hydrogen atoms
were treated as idealized contributions. Absolute stereochemistries
were determined by the values of the Flack parameters. For 9, a
molecule of highly disordered methylene chloride was rendered
using SQUEEZE, which treats electron densities in void spaces as
diffuse contributions. All software used was contained in either
the libraries distributed by Bruker AXS (Madison, WI) or in the
PLATON suite of programs by A. Spek.
1
{1H} NMR (C6D6): δ -49.1 (purity 94%, other peak -38.2). H
NMR (C6D6): δ 7.13 (d, JP-H ) 3, 2H, Ar), 5.94-5.83 (m, 1H,
CH allyl), 5.05-4.99 (ddm, JP-H ) 5, J ) 18, 1, 1H, allyl), 4.94-
4.91 (dm, J ) 10, 1H, allyl), 4.18-4.08 (m, 2H, i-Pr), 2.79-2.67
(overlapping m, 3H, P-CH2 + CH, i-Pr), 1.42 (d, JP-H ) 6, 3H,
P-Me), 1.31 (d, J ) 7, 6H, CH3), 1.30 (d, J ) 7, 6H, CH3), 1.20
(d, J ) 7, 6H, CH3). 13C{1H} NMR (C6D6): δ 156.3 (d, J ) 21,
quat), 150.9 (quat), 135.9 (d, J ) 23, CH allyl), 130.8 (d, J ) 41,
quat), 122.6 (d, J ) 6, Ar), 116.3 (d, J ) 19, CH2 allyl), 35.4 (d,
J ) 25, P-CH2), 35.0 (CH, i-Pr), 31.8 (d, J ) 34, CH, i-Pr), 25.5
(d, J ) 1, CH3), 25.4 (CH3), 24.4 (d, J ) 2, CH3), 11.7 (d, J ) 32,
P-CH3).
Acknowledgment. We thank the National Science Founda-
tion for support.
Supporting Information Available: Details of the X-ray
structure determinations (CIF files and tables). This information is
available free of charge via the Internet at http://pubs.acs.org.
OM060614Y