Reactivity of diaryliodine(III) triflates toward palladium(II) and platinum(II): Reactions of C(sp2)-I bonds to form arylmetal(IV) complexes; access to dialky(aryl)metal(IV), 1,4-benzenediyl-bridged platinum (IV); and triphenylplatinum(IV) species; and structural studies of platinum(IV) complexes

Article abstract of DOI:10.1021/om040023c

The reactivity of diaryliodine(III) triflates toward palladium(II) and platinum(II) is discussed. The reactions mirror, for Pd(II)/Pd(IV), the role of iodine(III) reagents in catalysis reactions involving Pd(0)/Pd(II) cycles. The facile synthesis and stability at ambient temperature of PtIPh ₃(Bu₂^tbpy) indicate that it should be possible to develop an extensive chemistry of triarylplatinum(IV) species in the absence of intramolecular coordination by the aryl groups. Transfer of aryl cations from [Ar₂I]⁺ to organic and organometallic reagents containing a nucleophilic center occurs via nucleophilic attack at the iodine(III) center.

Full text of DOI:10.1021/om040023c

3466
Organometallics 2004, 23, 3466-3473
Rea ctivity of Dia r yliod in e(III) Tr ifla tes tow a r d
P a lla d iu m (II) a n d P la tin u m (II): Rea ction s of C(sp 2)-I
Bon d s to F or m Ar ylm eta l(IV) Com p lexes; Access to
Dia lk yl(a r yl)m eta l(IV), 1,4-Ben zen ed iyl-Br id ged
P la tin u m (IV), a n d Tr ip h en ylp la tin u m (IV) Sp ecies; a n d
Str u ctu r a l Stu d ies of P la tin u m (IV) Com p lexes
Allan J . Canty,*,† J im Patel,† Thomas Rodemann,† J ohn H. Ryan,†
Brian W. Skelton,‡ and Allan H. White‡
School of Chemistry, University of Tasmania, Hobart, Tasmania 7001, Australia, and
School of Biomedical & Chemical Sciences, University of Western Australia,
Crawley, Western Australia 6009, Australia
Received February 27, 2004
Diphenyliodine(III) triflate is able to transfer Ph+ to Pd(II) and Pt(II) with cleavage of a
phenyl-iodine bond and formation of metal(IV) species, leading to the first identified transfer
of Ph+ to Pd(II) from an aryl-halogen bond, and, for platinum, a methodology providing a
facile route to dimethyl(aryl)platinum(IV) and 1,4-arenediyl-bridged Pt(IV) species and the
first archetypal triarylplatinum(IV) complex. Thus, [IPh2][OTf] reacts with PtMe2(bpy) (bpy
) 2,2′-bipyridine) at -50 °C to form iodobenzene and the Pt(IV) complex trans-PtIV(OTf)Me2-
Ph(N∼N) (1b) (Ph trans to OTf), and on addition of NaI, the species PtIMe2Ph(bpy) (2a (Ph
cis to I) and 2b (Ph trans to I) in 2:1 ratio) may be isolated at -20 °C. Similarly, metalla-
(II)cyclopentane complexes M(C4H8)(bpy) react with [IPh2][OTf] to form trans-Pt(OTf)(C4H8)-
Ph(bpy) (3b) and a 1:1 ratio of cis- (4a ) and trans-Pd(OTf)(C4H8)Ph(bpy) (4b); addition of
halide ion gives trans-PtI(C4H8)Ph(bpy) (5b) and a 1:3 ratio of cis and trans isomers for
PdI(C4H8)Ph(bpy) (6a , 6b) and PdCl(C4H8)Ph(bpy) (7a , 7b). Complex 5b isomerizes to form
a 2:1 mixture of cis-PtI(C4H8)Ph(bpy) (5a ) and 5b at ambient temperature in acetone.
Dimethyl(2,2′-bipyridine)palladium(II) reacts with [IPh2][OTf] to form Pd(OTf)Me2Ph(bpy),
followed by transfer of a methyl group from Pd(IV) to Pd(II), to form trimethylpalladium-
(IV) species. Dimethyl(2,2′-bipyridine)platinum(II) reacts with [IPh(C6H4-4-I)][OTf], followed
by addition of sodium iodide, to form a 1:1 mixture of trans-PtIMe2Ph(bpy) (2b) and trans-
PtIMe2(C6H4-4-I)(bpy) (8b), and with [IPh(C6H4-4-IPh)][OTf]2 to form the 1,4-arenediyl
complex trans-1,4-{PtIMe2(bpy)}2C6H4 (9b). Diphenyl{di(tert-butyl)-2,2′-bipyridine}platinum-
(II) reacts with [IPh2][OTf] at 25 °C over 2 days to form the triphenylplatinum(IV) complex
Pt(OTf)Ph3(But bpy) (10), and addition of iodide ion results in isolation of PtIPh3(But bpy)
2
2
(11). Structural studies of trans-PtIMe2Ph(bpy) (2b) and trans-Pt(C4H8)Ph(bpy) (5b) reveal
distorted octahedral geometry and the fac-PtC3 configuration expected for all of the metal-
(IV) complexes. The compound [IPh(C6H4-4-I)][OTf] has two sets of cation-anion pairs with
a complex array of weak interactions, and the cations have C-I-C angles close to 90°.
In tr od u ction
“model” oxidative addition reactions involving detected
Pd(IV) species to add substance to these suggestions.
There are also a range of other possible processes that
could be invoked to explain the apparent involvement
of Pd(IV) in catalysis, in particular facile exchange of
aryl groups between Pd(II) centers or reduction of
precatalysts to Pd(0) species that can then act as either
heterogeneous or homogeneous catalysts.3 Reduction to
Pd(0) may occur in several ways, e.g., by reaction with
the solvent or other reagents, or one-electron oxidation
A key process in reactions catalyzed by palladium
complexes is the oxidative addition of C(sp2)-X bonds
to Pd(0) substrates, in particular aryl and alkenyl
halides R-X where the organic group is formally
transferred as R+ to give PdIIR.1 Related reactions of
Pd(II) substrates with C(sp2)-X bonds to form Pd(IV)
intermediates in catalysis have often been suggested,2
although there appears to be an absence of reports of
* To whom correspondence should be addressed. E-mail: Allan.
Canty@utas.edu.au. Fax: (61-3) 6226-2858.
† University of Tasmania.
(2) (a) de Meijere, A.; Meyer, F. E. Angew. Chem., Int. Ed. Engl.
1994, 33, 2379. (b) Shaw, B. L.; Perera, S. D. Chem. Commun. 1998,
1863. (c) Luo, F.-T.; J eevanandam, A.; Basu, M. K. Tetrahedron Lett.
1998, 39, 7939. (d) Catellani, M. Pure Appl. Chem. 2002, 74, 63. (e)
Chinnasamy, R.; Kubota, Y.; Miwa, M.; Sugi, Y. Synthesis 2002, 2171.
(e) Catellani, M. In Transition Metal Catalysed Reactions; Murahashi,
S.-I., Davies, S.-G., Eds.; IUPAC, 2003; p 169.
‡ University of Western Australia.
(1) (a) Stille, J . K.; Lau, K. S. Y. Acc. Chem. Res. 1977, 10, 434. (b)
Alcazar-Roman, L. M.; Hartwig, J . F. Organometallics 2002, 21, 491,
and references therein.
10.1021/om040023c CCC: $27.50 © 2004 American Chemical Society
Publication on Web 06/04/2004

Reactivity of Diaryliodine(III) Triflates
Organometallics, Vol. 23, No. 14, 2004 3467
by the aryl halide reagent leading to decomposition to
Pd(0).3 Alternatively, it is feasible that oxidative addi-
tion reactions of aryl halides to Pd(II) substrates do
provide Pd(IV) intermediates that are insufficiently
stable to allow their observation.
centers to form M(IV) complexes (M ) Pd, Pt) does occur
and that this methodology provides a new and facile
route to dialkyl(aryl)platinum(IV) complexes, including
a 1,4-benzenediyl-bridged complex and the first route
to an archetypal triarylplatinum(IV) complex. Prelimi-
nary communications of part of this work have ap-
peared.10
As part of a search for reactions that could model the
addition of C(sp2)-X bonds to Pd(II) to form Pd(IV)
species, we have been attracted by the developing
importance of catalytic reactions involving hypervalent
iodine(III) reagents [IAr(R)][X] [X usually triflate (OTf)
or BF4] in Pd(0)/Pd(II) cycles.4,5 These reagents transfer
aryl and related groups (R) such as alkenyl and alkynyl
to Pd(0) to form PdIIR intermediates, involving cleavage
of the R-I bond and elimination of ArI. It has been
reported that alkynyl and vinyl groups can be trans-
ferred from iodine(III) reagents to Rh(I) and Ir(I)
complexes to form M(III) complexes,4,6 alkynyl groups
to Pt(0) to form Pt(II) complexes,4,7 and possibly phenyl
groups to Y(0).8 Encouraged by these reports we have
explored the reactivity of [IPh2][OTf] toward Pd(II)
reagents, and toward Pt(II) in view of the higher
reactivity of Pt(II) toward aryl halides demonstrated for
some systems to give Pt(IV) species.9 Although this
chemistry does not formally model aryl halide oxidative
addition, we report here that transfer of Ar+ to M(II)
Exp er im en ta l Section
The reagents MMe2(bpy) (M ) Pd,11 Pt12) (bpy ) 2,2′-
bipyridine), M(C4H8)(bpy) (M ) Pd,13 Pt14), PtPh2(But bpy)
2
(But bpy ) 4,4′-bis(tert-butyl)-2,2′-bipyridine),15 [IPh2][OTf],16
2
17
and [IPh(C6H4-4-IPh)][OTf]2 were prepared as described. A
preparation of [IPh(C6H4-4-I)][OTf] similar to that reported for
a successful synthesis16a,18 was developed, using a longer
reaction time and a 0.5:1 mole ratio of trifluoromethanesulfonic
anhydride to iodosylbenzene, rather than 1:1 as reported.
Solvents were dried and distilled and stored under nitrogen,
1
and all procedures were carried out under nitrogen. H NMR
spectra were recorded on a Varian Unity Innova 400 MHz wide
bore instrument at 399.7 MHz or on a Varian Mercury Plus
300 MHz spectrometer at 299.9 MHz, at room temperature
unless indicated otherwise. 13C NMR spectra at 75.4 MHz and
COSY, HMQC, and HMBC spectra were recorded on a Varian
Mercury Plus 300 MHz spectrometer. Chemical shifts are
given in ppm relative to SiMe4. Microanalyses and LSMIS were
performed by the Central Science Laboratory, University of
Tasmania. GC/MS analyses were performed using an HP 5890
gas chromatograph equipped with an HP5790 MSD and a 25
m × 0.32 mm HP1 column (0.52 µm film thickness, He at 10
psi).
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added dropwise to a stirred suspension of iodosylbenzene (0.66
g, 3.0 mmol) in dichloromethane (5 mL) at room temperature.
Stirring was continued for 48 h, cyclohexene (0.3 mL, 3.0
mmol) was added, and the resulting mixture was stirred for 4
h. The solvent was removed under vacuum, and the residue
was treated with diethyl ether (5 mL) to give the product as a
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3468 Organometallics, Vol. 23, No. 14, 2004
Canty et al.
Syn th esis of P t(IV) a n d P d (IV) Com p lexes. The com-
plexes 2a , 5b, 9b, and 11 and mixtures of 2a and 2b and of
2b and 8b were isolated as solids; other species were detected
residue at - 50 °C. The mixture was stirred for 5 min at -50
°C and filtered. The filtrate was concentrated to half its
volume, and small amounts of pentane were added. The
solution was kept for several days at -20 °C. The precipitate
that formed was collected by filtration, washed with diethyl
ether (2 × 5 mL), and dried in a vacuum (63 mg, 86%). 1H
NMR: (CD2Cl2, -50 °C): δ 9.06 (m, 2H, H6), 7.94 (m, 4H,
1
by H NMR spectroscopy.
tr a n s-P t(OTf)Me2P h (bp y) (1b). Diphenyliodonium triflate
(3.9 mg, 0.013 mmol) was added to a stirred solution of PtMe2-
(bpy) (5.0 mg, 0.013 mmol) in (CD3)2CO (1 mL) at -50 °C. The
3
1
H3,4), 7.65 (m, 2H, H5), 6.96 (m, J HPt ) 54.0 Hz, 2H, H2,6-
mixture was stirred for a further 5 min at -50 °C. H NMR
(Ph)), 6.78 (m, 3H, H3-5(Ph)), 3.63 (m, J HPt ) 106.3 Hz, 2H,
CH2), 2.35 (m, J HPt ) 54.9 Hz, 2H, CH2), 1.44 (m, J HPt ) 63.6
Hz, 2H, CH2), 1.10-0.90 (m(b), 2H, CH2). Anal. Calcd for
(-60 °C): δ 9.39 (m, 2H, H6), 8.72 (m, 2H, H3), 8,43 (m, 2H,
2
H4), 8.08 (m, 2H, H5), 6.80 (m, 5H, Ph), 1.50 (s, J HPt ) 67.6
Hz, 6H, PtCH3).
C
20H21N2IPt: C, 39.29; H, 3.46; N, 4.58. Found: C, 39.37; H,
cis-P tIMe2P h (bp y) (2a ) a n d tr a n s-P tIMe2P h (bp y) (2b).
Diphenyliodonium triflate (39 mg, 0.13 mmol) was added to a
stirred solution of PtMe2(bpy) (50 mg, 0.13 mmol) in acetone
(10 mL) at -50 °C. The mixture was stirred for a further 5
min at -50 °C and allowed to warm to room temperature, and
sodium iodide (25 mg, 0.17 mmol) was added. The solvent was
removed in a vacuum, and dichloromethane (10 mL) was added
to the residue. The resulting mixture was stirred for 5 min
and filtered. The filtrate was concentrated to half its volume,
and small amounts of pentane were added. The solution was
kept for several days at -20 °C. The precipitate that formed
was collected by filtration, washed with diethyl ether (2 × 5
mL), and dried in a vacuum (69 mg, 91%). 1H NMR spectra
indicated a cis:trans isomer ratio of 2:1. The mixture of the
two isomers was partially separated by crystal habit to give
samples of the cis (2a , white powder) and trans isomers (2b,
yellow crystals). 1H NMR of 2a ((CD3)2CO): δ 9.11 (m, 1H,
H6), 8.84 (m, 1H, H6′), 8.76 (m, 1H, H3), 8.74 (m, 1H, H3′),
8.37 (m, 1H, H4), 8.32 (m, 1H, H4′), 7.93 (m, 1H, H5), 7.76
(m, 1H, H5′), 7.68 (br m, 2H, H2,6(Ph)), 7.02 (m, 3H, H3-
3.26; N, 4.39.
cis-P d I(C4H8)P h (bp y) (6a ) a n d tr a n s-P d I(C4H8)P h (bp y)
(6b). Diphenyliodonium triflate (4.7 mg, 0.016 mmol) was
added to a stirred solution of Pd(C4H8)(bpy) (5.0 mg, 0.016
mmol) in (CD3)2CO (1 mL) at -50 °C. The mixture was stirred
for a further 40 min at -50 °C, and sodium iodide (3.0 mg,
0.020 mmol) was added to give a 1:3 mixture of 6a and 6b. 1H
3
NMR (-50 °C) of 6a : δ 9.22 (d, J ) 4.4 Hz, 1H, H6), 8.79 (d,
3J ) 8.0 Hz, 1H, H3), 8.75 (d, J ) 8.0 Hz, 1H, H3′), 8.62 (d,
3
3J ) 4.4 Hz, 1H, H6′), 8.34 (‘t’, 1H, H4), 8.26 (‘t’, 1H, H4′),
7.92 (‘dd’, 1H, H5), 7.70 (‘dd’, 1H, H5′), 7.07 (t, 3J ) 7.0 Hz,
1H, H4(Ph)), 3.98 (‘q’, 1H, CH2), 3.01 (‘q’, 1H, CH2), 1.67 (m(b),
1H, CH2), 1.40 (m(b), 2H, CH2), 1.22 (m(b), 1H, CH2), 1.05
3
(m(b), 2H, CH2); 6b: δ 9.15 (d, J ) 4.4 Hz, 2H, H6), 8.42 (d,
3J ) 8.0 Hz, 2H, H3), 8.16 (‘t’, 2H, H4), 7.82 (‘dd’, 2H, H5), 7.2
[m, 2H, H2,6(Ph)], 6.88 (‘t’, 2H, H3,5(Ph)), 6.79 (t, 3J ) 7.2
Hz, 1H, H4(Ph)), 4.85 (m, 2H, CH2), 3.28 (m, 2H, CH2), 1.99
(m, 2H, CH2), 1.51 (m, 2H, CH2).
cis-P d Cl(C4H8)P h (bp y) (7a ) a n d tr a n s-P d Cl(C4H8)P h -
(bp y) (7b). Diphenyliodonium triflate (4.7 mg, 0.016 mmol)
was added to a stirred solution of Pd(C4H8)(bpy) (5.0 mg, 0.016
mmol) in (CD3)2CO (1 mL) at -50 °C. The mixture was stirred
for a further 40 min at -50 °C, and lithium chloride (1.0 mg,
0.024 mmol) was added to give a 1:3 mixture of 7a and 7b. 1H
2
2
5(Ph)), 1.71 (s, J HPt ) 71.1 Hz, 3H, PtCH3), 0.99 (s, J HPt
)
70.7 Hz, 3H, PtCH3). Anal. for 2a , Calcd for C18H19N2PtI: C,
1
36.93; H, 3.27; N, 4.79. Found: C, 36.74; H, 3.24; N, 4.88. H
NMR of 2b ((CD3)2CO): δ 9.27 (m, 2H, H6), 8.59 (m, 2H, H3),
8.27 (m, 2H, H4), 7.91 (m, 2H, H5), 7.04 (m, 2H, H2,6(Ph)),
2
3
6.73 (m, 3H, H3-5(Ph)), 1.77 (s, J HPt ) 71.1 Hz, 6H, PtCH3).
NMR (-50 °C) of 7a : δ 9.15 (d, J ) 4.4 Hz, 1H, H6), 8.71 (d,
3
tr a n s-P t(OTf)(C4H8)P h (bp y) (3b). Diphenyliodonium tri-
flate (3.6 mg, 0.012 mmol) was added to a stirred solution of
Pt(C4H8)(bpy) (5.0 mg, 0.012 mmol) in (CD3)2CO (1 mL) at -50
°C. The mixture was stirred for a further 5 min at -50 °C. 1H
3J ) 8.4 Hz, 1H, H3), 8.67 (d, J ) 8.2 Hz, 1H, H3′), 8.31 (‘t’,
1H, H4), 8.21 (‘t’, 1H, H4′), 7.92 (‘dd’, 1H, H5), 7.09 (d, 3J )
3
7.2 Hz, 2H, H2,6(Ph)), 6.98 (t, J ) 7.0 Hz, 1H, H4(Ph)), 3.74
(m(b), 1H, CH2), 2.86 (m(b), 1H, CH2), 1.21 (m(b), 2H, CH2);
3
3
3
NMR (-50 °C): δ 9.37 (m, 2H, H6), 8.72 (d, J ) 8.1 Hz, 2H,
7b: δ 9.08 (d, J ) 4.4 Hz, 2H, H6), 8.42 (d, J ) 8.0 Hz, 2H,
H3), 8.15 (‘t’, 2H, H4), 7.81 (‘dd’, 2H, H5), 7.33 (d, 3J ) 8.5 Hz,
2H, H2,6(Ph)), 6.86 (‘t’, 2H, H3,5(Ph)), 6.77 (t, 3J ) 6.8 Hz,
1H, H4(Ph)), 4.38 (m, 2H, CH2), 3.30 (m, 2H, CH2), 1.79 (m,
2H, CH2), 1.32 (m, 2H, CH2).
H3), 8.44 (‘t’, 2H, H4), 8.06 (m, 2H, H5), 7.15 [m, 2H, H2,6-
(Ph)], 6.80 (m, 3H, H3-5(Ph)).
cis-P d (OTf)(C4H 8)P h (b p y) (4a ) a n d tr a n s-P d (OTf)-
(C4H8)P h (bp y) (4b). Diphenyliodonium triflate (4.7 mg, 0.016
mmol) was added to a stirred solution of Pd(C4H8)(bpy) (5.0
mg, 0.016 mmol) in (CD3)2CO (1 mL) at -70 °C. The mixture
was stirred for a further 40 min at -70 °C to give a 1:1 mixture
tr a n s-P tIMe2(C6H4-4-I)(bp y) (8b) a n d tr a n s-P tIMe2P h -
(bp y) (2b). (4-Iodophenyl)(phenyl)iodonium triflate (109.2 mg,
0.20 mmol) was added to a stirred solution of PtMe2(bpy) (75.0
mg, 0.20 mmol) in acetone (10 mL) at -50 °C. The mixture
was stirred for 30 min at -50 °C, and sodium iodide (30 mg,
0.20 mmol) was added. The solvent was removed in a vacuum
at -50 °C, and dichloromethane (5 mL) at -50 °C was added
to the residue. The resulting mixture was stirred for 5 min at
-50 °C and filtered, and the solvent removed from the filtrate
at -50 °C. The residue was washed with diethyl ether (3 × 5
mL), and the solid dissolved in acetone (10 mL) at -50 °C and
kept at -80 °C for 1 week. The solvent was removed at -50
°C under a vacuum to give a yellow solid (118.2 mg, 92%) as
1
3
of 4a and 4b. H NMR (-50 °C) of 4a : δ 9.28 (d, J ) 5.1 Hz,
3
3
1H, H6), 8.86 (d, J ) 7.9 Hz, 1H, H3), 8.82 (d, J ) 7.8 Hz,
1H, H3′), 3.76 [m(b), 1H, CH2]. 1H NMR (-50 °C) of 4b: δ
3
3
9.23 (d, J ) 5.2 Hz, 2H, H6), 8.57 (d, J ) 8.0 Hz, 2H, H3),
8.30 (‘t’, 2H, H4), 7.95 (‘dd’, 2H, H5), 7.27 (d, J ) 7.6 Hz, 2H,
3
H2,6(Ph)), 6.91-6.83 (m, 3H, H3-5(Ph)), 4.15 (m, 2H, CH2),
3.50 (m, 2H, 2H, CH2), 1.73 (m, 2H, CH2), 1.43 (m, 2H, CH2).
cis-P tI(C4H8)P h (bp y) (5a ). A solution of trans-PtI(C4H8)-
Ph(bpy) (5b) (5.0 mg, 0.0082 mmol) in (CD3)2CO (1 mL) was
left standing at room temperature for 16 h to give a 2:1 mixture
of 5a and 5b. 1H NMR (CD2Cl2) of 5a : δ 9.11 (m, 2H, H6),
8.30 (m, 2H, H3), 8.13 (‘t’, 1H, H4), 8.01 (‘t’, 1H, H4′), 7.79 (br
m, 2H, H2,6(Ph)), 7.21 (m, 2H, H5), 7.08 (m(b), 3H, H3-H5-
(Ph)), 2.91 (m(b), 2H, CH2), 2.29 (m, 1H, CH2), 1.72 (m, 1H,
CH2), 1.28 (br, m, 1H, CH2), 0.98 (br, m, 1H, CH2), 0.64 (br,
m, 1H, CH2), 0.56 (br, m, 1H, CH2).
tr a n s-P tI(C4H8)P h (bp y) (5b). Diphenyliodonium triflate
(36 mg, 0.12 mmol) was added to a stirred solution of Pt(C4H8)-
(bpy) (50 mg, 0.12 mmol) in acetone (10 mL) at -50 °C. The
mixture was stirred for a further 5 min at -50 °C, and sodium
iodide (25 mg, 0.17 mmol) was added. The solvent was removed
in a vacuum, and dichloromethane (10 mL) was added to the
1
a 1:1 mixture of 8b and 2b. H NMR (-50 °C) of 8b: δ 9.39
(m, 2H, H6), 8.86 (m, 2H, H3), 8.41 (m, 2H, H4), 7.98 (m, 2H,
3
3
H5), 7.09 (d, J ) 8.4 Hz, 2H, C6H4), 6.64 (d, J ) 8.4 Hz, 2H,
2
C6H4), 1.68 (s, J HPt ) 69.8 Hz, 6H, Me). HRMS (LSI): calcd
for C18H18N2194PtI ((M - I)+) 583.01428, found 583.01395.
tr a n s-1,4-{P tIMe2(bp y)}2C6H4 (9b). 1,4-Bis(phenyliodo-
nium)benzene (121 mg, 0.32 mmol) was added to a stirred
solution of PtMe2(bpy) (124 mg, 0.16 mmol) in acetone (15 mL)
at -50 °C. The mixture was stirred for 30 min at -50 °C, and
sodium iodide (48 mg, 0.32 mmol) was added. The solvent was
removed in a vacuum at -50 °C, and dichloromethane (10 mL)
at -50 °C was added to the residue. The resulting mixture

Reactivity of Diaryliodine(III) Triflates
Organometallics, Vol. 23, No. 14, 2004 3469
Ta ble 1. Selected Bon d Dista n ces (Å) a n d An gles
(d eg) for tr a n s-P tIMe2P h (bp y) (2b) a n d
tr a n s-P tI(C4H8)P h (bp y) (5b)
2b
5b
Bond Distances
2.034(4)
Pt-C(1)
2.04(1)
Pt-C(10a, 10b)
Pt-N(11a, 11b)
Pt-I
2.060(5), 2.058(5) 2.07(1), 2.05(1)
2.151(3), 2.151(3) 2.175(8), 2.158(9)
2.7631(4)
2.759(1)
Bond Angles
89.0(2), 88.9(2)
90.8(1), 90.5(2)
178.2(1)
C(1)-Pt-C(10a, 10b)
C(1)-Pt-N(11a, 11b)
C(1)-Pt-I
90.8(5), 89.3(5)
88.5(4), 90.5(4)
179.6(3)
C(10a)-Pt-C(10b)
84.7(2)
83.0(5)
C(10a)-Pt-N(11a, 11b) 175.8(2), 99.4(2)
C(10b)-Pt-N(11a, 11b) 99.5(1), 175.9(2)
177.2(4), 101.4(4)
99.7(4), 175.6(4)
89.5(5), 91.0(5)
I-Pt-C(10a, 10b)
I-Pt-N(11a, 11b)
N(11a)-Pt-N(11b)
Pt-C(1)-C(2, 6)
90.8(1), 92.8(1)
89.18(9), 87.72(9) 91.2(3), 89.2(3)
76.4(1) 75.9(3)
121.9(3), 120.4(3) 120.9(8), 121.7(9)
Pt-N(11a)-C(12a, 16a) 115.8(2), 125.4(3) 124.9(7), 116.4(7)
Pt-N(11b)-C(12b, 16b) 115.9(3), 124.9(3) 125.0(8), 115.5(6)
was stirred for 5 min at -50 °C and filtered, and the solvent
removed from the filtrate at -50 °C. Column chromatography
(silica, ethyl acetate) of the residue at ambient temperature
gave the product (9b) (Rf ) 0.65) as a yellow solid (43 mg, 35%).
Other isomers together with 9b occur in the next fraction as
1
3
a broad band. H NMR of 9b: δ 9.05 (m, 2H, H6), 8.77 (d, J
) 8.3 Hz, 4H, H3), 8.33 (‘td’, 4H, H4), 7.91 (‘ddd’, 4H, H5),
7.55 (s, 4H, C6H4), 2.38 (s, J HPt ) 73.0 Hz, 12H, Me). 13C
2
NMR: δ 155.9 (C2), 148.9 (C6), 141.1 (C4), 140.4 (CH(C6H4)),
128.2 (C5), 125.4 (C3), 93.9 (C(C6H4)), -15.1 (Me). The complex
would not ionize satisfactorily to give HRMS (LSI) or ESMS.
P tIP h 3(Bu t2bp y) (11). Diphenyliodonium triflate (13.9 mg,
0.032 mmol) was added to a stirred solution of PtPh2(But bpy)
2
(20.0 mg, 0.032 mmol) in acetone (5 mL) at ambient temper-
ature. The mixture was stirred for 2 days, and sodium iodide
(5 mg, 0.033 mmol) was added. The solvent was removed in a
vacuum, and dichloromethane (5 mL) was added to the
residue. The resulting mixture was stirred for 5 min and
filtered, and the solvent removed from the filtrate to give a
yellow solid (22.3 mg, 85%). A small amount was recrystallized
from diethyl ether/pentane for microanalysis. 1H NMR ((CD3)2-
CO): δ 8.90 (m, 2H, H6), 8.61 (d, 3J ) 1.9 Hz, 2H, H), 7.86 (d,
3J HPt ) 46.8 Hz, 3J ) 7.3 Hz, 4H, H2,6(Ph)), 7.83 (‘dd’, 2H,
H5), 6.94 (m, 2H, H4(Ph)), 6.86 (m, 4H, H3,5(Ph)), 6.72 (m,
2H, H2,6(Ph)), 6.62 (m, 3H, H3-5(Ph)), 1.41 (s, 18H, Me).
Anal. Calcd for C36H39N2IPt: C, 52.62; H, 4.78; N, 3.41.
Found: C, 52.32; H, 4.86; N, 3.23.
F igu r e 1. Projections of molecules of (a) trans-PtIMe2Ph-
(bpy) (2b) and (b) trans-PtI(C4H8)Ph(bpy) (5b) showing
disorder for the platinacyclopentane ring.
Decom position of P allada(IV)cyclopen tan e Com plexes
4, 6, a n d 7. An acetone solution containing the isomeric
mixture of complexes generated in solution at -50 °C, and thus
containing excess halide for 6 and 7, was allowed to warm to
ambient temperature and left standing in a sealed flask for
24 h. The organic components were analyzed by GC/MS.
Str u ctu r e Deter m in a tion s. Crystals of 2b and 5b were
obtained at -20 °C from solutions of complexes in dichlo-
romethane/diethyl ether and dichloromethane/pentane, re-
spectively. Full spheres of CCD area-detector diffractometer
data were measured (Bruker AXS instrument, 2θmax ) 58°,
ω-scans, monochromatic Mo KR radiation, λ ) 0.71073 Å; T
ca. 153 K) yielding Nt total reflections, merging to N unique
(Rint cited) after ‘empirical’/multiscan absorption correction
(proprietary software), No with F > 4σ(F) considered ‘observed’
and used in the full-matrix least squares refinements, refining
anisotropic thermal parameter forms for the non-hydrogen
scattering factors were employed within the Xtal 3.7 program
system.19 Table 1 shows selected structural parameters, and
Figure 1 depicts non-hydrogen atoms with 50% probability
amplitude displacement envelopes, hydrogen atoms having
arbitrary radii of 0.1 Å.
Resu lts
Reactions were studied initially at low temperature
by 1H NMR using (CD3)2CO as a solvent. Although
reactivity of Pd(II) species with [IPh2][OTf] was de-
tected, Pd(IV) species could not be isolated owing to very
low stability, so that their characterization relied on
comparison of spectra with reported palladium com-
plexes prepared by other methods (PdMePh(bpy),20
PdIMe3(bpy),21 PdIMe2Ph(bpy),22 PdI(C4H8)Me(bpy)23)
and more robust Pt(IV) analogues. The isomer designa-
atoms, (x, y, z Uiso
) being constrained at estimated values.
H
As modeled, the central atoms of the (CH2)2 group of 5b
exhibited disorder over two sets of sites with populations of
0.5. Conventional residuals R, Rw on |F| are cited at conver-
gence (weights: (σ2(F) + 0.0004F2)-1). Neutral atom complex
(19) Hall, S. R., Du Boulay, D. J ., Olthof-Hazekamp, R., Eds. The
XTAL 3.7 System; University of Western Australia, 2001.

3470 Organometallics, Vol. 23, No. 14, 2004
Canty et al.
Sch em e 1
Sch em e 2
tions cis and trans refer to the disposition of aryl with
respect to halogeno or triflate groups (Schemes 1 and
2). Aryl iodide byproducts of aryl group transfer from
iodine(III) reagents were detected for all reactions, viz.,
PhI from [IPh2][OTf] and [IPh(C6H4-4-IPh)][OTf]2, and
both PhI and 1,4-C6H4I2 from [IPh(C6H4-4-I)][OTf]2.

Reactivity of Diaryliodine(III) Triflates
Organometallics, Vol. 23, No. 14, 2004 3471
Dim eth yl(p h en yl)m eta l(IV) Sp ecies. The reaction
of PdMe2(bpy) with [IPh2][OTf] in 1:1 mole ratio at -50
°C gave complex spectra that were difficult to interpret,
and only about half of the iodonium reagent was
consumed. On addition of sodium iodide to this solution,
the species PdIMe3(bpy), PdMePh(bpy), and a small
amount of PdIMe2Ph(bpy) were detected, where PdIMe2-
Ph(bpy) is present as cis and trans isomers in the same
ratio (1:1) as reported for its synthesis via the oxidative
addition of iodomethane to PdMePh(bpy).22 Formation
of the trimethylpalladium(IV) complex is indicative of
transfer of a methyl group between palladium centers,
a reaction that is often observed in organopalladium-
(IV) chemistry; for example, PdIMe2Ph(bpy) reacts with
PdMe2(bpy) to form PdMePh(bpy) and PdIMe3(bpy),
respectively.22 Since all of the PdMe2(bpy) reagent, but
not [IPh2][OTf], is consumed prior to addition of sodium
iodide, the NMR observations are consistent with fast
methyl group transfer from Pd(OTf)Me2Ph(bpy) to
PdMe2(bpy). Exchange reactions involving Pd(OTf)Me2-
Ph(bpy) are expected to be more facile than those
involving PdIMe2Ph(bpy), as the exchange reaction is
favored by weak donor ligands at Pd(IV) and ligand
disssociation.
Meta lla (IV)cyclop en ta n e Sp ecies. The alkyl group
exchange reactions exhibited by PdIMe2Ph(bpy)22 and
Pd(OTf)Me2Ph(bpy) (see above) are not expected to occur
when the methyl groups are replaced by a palladacycle;
for example, PdI(C4H8)Me(bpy) does not react with Pd-
(C4H8)(bpy).23 Thus, the reaction of the pallada(II)-
cyclopentane complex Pd(C4H8)(bpy) with [IPh2][OTf]
1
was studied at -50 °C, resulting in H NMR detection
of Pd(OTf)(C4H8)Ph(bpy) with a cis (4a ):trans (4b)
isomer ratio of 1:1 (Scheme 1). In contrast to the reaction
of PdMe2(bpy) with [IPh2][OTf] and consistent with the
absence of exchange reactions, all of the iodine(III)
reagent was consumed in the reaction. Addition of
lithium chloride or sodium iodide resulted in formation
of PdX(C4H8)Ph(bpy) (X ) Cl, I), occurring with a cis:
trans ratio of 1:3. The Pd(IV) species are unstable. The
Pt(IV) complex Pt(OTf)(C4H8)(bpy) (3) forms as a trans
isomer at -50 °C, and addition of sodium iodide and
workup at -20 °C allowed the isolation of trans-PtI-
(C4H8)(bpy) (5b) (Scheme 1), which in solution at
ambient temperature isomerizes to form a 2:1 mixture
of cis and trans isomers. The trans complex (5b) was
characterized by X-ray crystallography (see below).
1H NMR spectra for the metallacyclopentane com-
plexes show broad and/or complex multiplets for meth-
ylene protons and in the case of 3b are too broad to allow
confident assignment and are thus not intructive for
assignment to isomers. The presence of isomeric mix-
tures has precluded complete assignment for some of
the cis complexes. However, most resonances for the bpy
ligand are well resolved and assist with structural
assignment; for example, the trans complexes exhibit a
single H(6) resonance integrating for two protons (3b,
4b, 5b, 6b, 7b), and the cis complexes exhibit two
resonances (6a ), or one resonance integrating as one
proton in those cases where the other resonance is
obscured (4a and 7a , which exhibit two H(3) reso-
nances).
In contrast, PtMe2(bpy) reacts with [IPh2][OTf] at -50
°C to give a spectrum consistent with the presence of
trans-Pt(OTf)Me2Ph(bpy) (1b) (Scheme 1), exhibiting
one pyridyl group environment, and for which the
triflate group is assumed to be coordinated as reported
for the closely related Pt(OTf)Me3{(2,6-Pri C6H3NCH)2-
2
N,N′}24 in the solid state and Pt(OTf)Me3(tmeda) (tmeda
) N,N,N′,N′-tetramethylethylenediamine) in solution.25
Complex 1b reacts with sodium iodide at ambient
temperature to give a mixture of cis (2a ) and trans (2b)
isomers of PtIMe2Ph(bpy) in 2:1 ratio (Scheme 1),
resulting in isolation of the isomers as a solid mixture
in 91% yield from PtMe2(bpy). The isomers exhibit
different crystal habits, allowing separation of a pure
sample of the trans isomer (2b) suitable for X-ray
crystallography and an impure sample of the cis isomer.
Solutions of 2a or 2b in acetone show isomerization back
to the 2:1 ratio of isomers over a period of a few hours
at ambient temperature.
The decomposition of a range of isolated pure com-
plexes PdX(C4H8)R(bpy) (X ) halogen, R ) alkyl) has
been reported, indicating that reductive elimination via
R-C4H8 coupling occurs followed by decomposition of
undetected PdIIC4H8R species to give substituted butenes
and butanes.23 The less stable complexes PdX(C4H8)-
Ph(bpy) [X ) OTf (4a , 4b), I (6a , 6b), Cl (7a , 7b)] were
generated in solution, and their decomposition was
examined at ambient temperature and thus in the
presence of iodobenzene (quantitatively from [IPh2]-
[OTf]) and, for 6 and 7, triflate and excess sodium iodide
or lithium chloride. Black suspensions were obtained,
1H NMR spectra revealed traces of butenes and cyclobu-
tane, and some PdCl2(bpy) could be isolated from the
decomposition of 7. Using iodobenzene as a reference
product, GC/MS revealed Ph-C4 species accounting for
99% of the Pd(IV) complex for X ) OTf, 65-80% for X
) I, and 49% for X ) Cl. The dominant products were
phenylbutenes (70% for X ) OTf, 50-65% for X ) I,
18% for X ) Cl), together with butylbenzene (22% for
OTf, 15% for I, 4% for Cl) and phenyl(propyl)methanone
(7% for OTf, 30% for Cl), where the ketone is assumed
to arise from oxidation of alkenes in the presence of
palladium species.
The structural analysis of 2b and partial separation
1
of the cis isomer (2a ) allow confirmation of H NMR
assignments for the isomers; for example, the cis isomer
exhibits two pyridyl and methyl group environments
and the trans isomer exhibits one environment. Com-
1
parison of H NMR spectra for isomers of MIMe2Ph-
(bpy) (M ) Pd, Pt) confirms the earlier assignments of
spectra and isomer ratio for the unstable Pd(IV) com-
plexes for which structural determinations were not
feasible.22
(20) Markies, B. A.; Canty, A. J .; de Graaf, W.; Boersma, J .; J anssen,
M. D.; Hogerheide, M. P.; Smeets, W. J . J .; Spek, A. L.; van Koten, G.
J . Organomet. Chem. 1994, 482, 191.
(21) Byers, P. K.; Canty, A. J .; Skelton, B. W.; White, A. H.
Organometallics 1990, 9, 826.
(22) Markies, B. A,; Canty, A. J .; Boersma, J .; van Koten, G.
Organometallics 1994, 13, 2053.
(23) Canty, A. J .; Hoare, J . L.; Davies, N. W.; Traill, P. R. Organo-
metallics 1998, 17, 2046.
(24) Hill, G. S.; Yap, G. P. A.; Puddephatt, R. J . Organometallics
1999, 18, 1408.
(25) Gschwind, R. M.; Schlecht, S. J . Chem. Soc., Dalton Trans.
1999, 1891.
p a r a -Iod op h en ylp la t in u m (IV) a n d 1,4-Ar en e-
d iylp la tin u m (IV) Sp ecies. In view of the facile reac-

3472 Organometallics, Vol. 23, No. 14, 2004
Canty et al.
tivity of PtMe2(bpy) with [IPh2][OTf] at low tempera-
tures we have explored its reactivity toward an iodonium
reagent containing different aryl groups bonded to
iodine(III), [IPh(C6H4-4-I)][OTf], and toward a reagent
containing two iodine(III) centers in a search for new
routes to bridging 1,4-arenediyl(IV) species (Scheme 2).
The reagent [IPh(C6H4-4-I)][OTf], structurally charac-
terized,26 gave a 1:1 mixture of trans isomers resulting
from transfer of phenyl (2b) and 4-iodophenyl (8b)
groups at -50 °C, and on warming to ambient temper-
ature, isomerization occurred to give a 1:1 ratio of cis
and trans isomers (2a , 2b) (as expected from Scheme
1) and a 1:1 ratio of cis and trans isomers for PtIMe2-
(C6H4-4-I)(bpy). The reagent [IPh(C6H4-4-IPh)][OTf]2,
containing two iodine(III) centers, gave a 35% yield of
a 1,4-benzenediyl-bridged complex (9b) in which both
Pt(IV) centers have the trans configuration at -50 °C,
together with other species that could not be separated
by column chromatography. Complex 9b is stable as the
trans isomer at ambient temperature for at least 1 week.
Str u ctu r a l Stu d ies of 2b a n d 5b. The complexes
exhibit distorted octahedral geometry for platinum(IV)
based on the presence of bidentate 2,2′-bipyridine and
a fac-PtC3 configuration and for which the platinacy-
clopentane ring exhibits disorder corresponding to the
presence of two conformers in 1:1 ratio (Figure 1). With
the C(10a)-Pt-C(10b) angle little changed on incorpo-
ration into the metallacycle ring, the platinum environ-
ments in the complexes are very similar, with only
minor deviation from overall m symmetry (the disor-
dered atoms of 5b excepted).
Discu ssion
The reactivity of the hypervalent iodine(III) reagent
[IPh2][OTf] toward Pd(II), in which a phenyl group is
transferred with cleavage of a C(sp2)-I bond and
formation of Pd(IV) products, provides a new pathway
to arylpalladium(IV) chemistry. The reactions mirror,
for Pd(II)/Pd(IV), the role of iodine(III) reagents in
catalysis reactions involving Pd(0)/Pd(II) cycles.
Synthetic routes to dialkyl(aryl)platinum(IV) species
reported to date are limited, since aryl-halogen bond
oxidative addition to dialkylplatinum(II) substrates
appears to require the presence of intramolecular
coordination,9 exemplified by the reaction of 2-(NMe2-
CH2CH2NCH)C6H4X (X ) Cl, Br, I) with [PtMe2(SMe2)]2
to form PtXMe2{2-(NMe2CH2CH2NCHC6H4-C,N,N′}.9a
Convenient syntheses of complexes 2, 5, and 9b provide
confidence that diaryliodine(III) reagents should provide
a general route to other dialkyl(aryl)platinum(IV) com-
plexes. Diaryl(alkyl)platinum(IV) species are readily
accessed via oxidative addition of alkyl halides to
diarylplatinum(II) substrates, e.g., initial trans oxida-
tive addition of iodomethane to PtPh2(bpy) followed by
isomerization to form a 2:1 mixture of cis- and trans-
PtIPh2Me(bpy),27 exhibiting isomerization behavior simi-
lar to that reported here for PtIMe2Ph(bpy) (2a , 2b). In
reactions of unsymmetrical species [IArR]+ with organic
nucleophiles, the more electron-withdrawing group is
eliminated,28 but in the reaction of PtMe2(bpy) with
[IPh(C6H4-4-I)][OTf] this effect is not sufficiently pro-
nounced to give a product distribution different from
the statistical 1:1 ratio observed for 2b and 8b (Scheme
1).
Complex 8b exhibits the characteristic AB pattern for
the p-iodo-substituted ring in 1H NMR spectra. A
complete 1H and 13C assignment for the 1,4-benzenediyl-
bridged complex (9b) was ascertained using COSY,
HMQC, and HMBC spectra; for example, in the HMBC
spectrum two cross-peaks for the 1,4-diylbenzene 1H
singlet (δ 7.55) were observed, corresponding to coupling
with the C(C6H4) and CH(C6H4) resonances at δ 93.9
and 141.1, respectively.
Syn th esis of a Tr ip h en ylp la tin u m (IV) Com p lex.
In view of the low solubility of PtPh2(bpy), the more
soluble species PtPh2(But bpy) was used as a reagent,
2
and reaction with [IPh2][OTf], followed by NaI, occurred
at ambient temperature to give an isolated yield of 85%
for PtIPh3(But bpy) (11). Complex 11 is stable at ambi-
2
ent temperature. The 1H NMR spectrum shows one
pyridyl and two phenyl environments, demonstrating
the fac-PtR3 environment expected for Pt(IV) and shown
crystallographically for 2b and 5b.
(26) [IPh(C6H4-4I)][OTf], C13H9F3I2O3S, M ) 556.1, monoclinic, space
5
group P21/n (C2h
,
No. 14; variant), a ) 9.8845(8) Å, b ) 14.898(1) Å,
c ) 22.312(2) Å, â ) 95.671(2)°, V ) 3269 Å3, Dc (Z ) 8) ) 2.259
cm-3, µMo ) 4.0 mm-1; specimen 0.35 × 0.25 × 0.17 mm; ‘T’min/max
g
)
0.56. The solid state array is composed of two sets of cation-anion
pairs, [IPh(C6H4-4-I)]+ with [O3SCF3]-, with a complex array of weak
interactions. The two sets of ion pairs are disposed similarly with the
substituted aromatic rings lying approximately parallel to each other
and to the ab face of the cell, inversion related to generate sheets to
either side, while the unsubstituted phenyl rings, approximately
parallel to each other, and to the ac faces of the cell, lie approximately
normal to the ab and bc faces. Interplanar dihedral angles within the
asymmetric unit are as follows: 1/1′,2,2′ 77.9(2)°, 7.4(1)°, 85.8(2)°; 1′/
2,2′ 84.9(2)°, 24.5(2)°; 2/2′ 80.0(2)°. The central C-S bonds of the anions
lie quasi-parallel to c. The unsubstituted phenyl rings and anions,
project outward from the ab plane, interdigitated with those from the
next array disposed to either side of z )1/2. The central, more positively
charged, iodine atoms interact with nearby oxygen atoms from their
companion anions (I(11)‚‚‚O(11), I(21)‚‚‚O(21) 3.028(4), 2.871(3) Å)
forming putative ion pairs. However, the pendant/substituent iodine
atoms also interact. Thus (I(14)‚‚‚O(12) (x, y-1, z) 3.088(3), I(24)‚‚‚
O(22) (x, y-1, z) 3.335(3) Å) linking the pairs into strings; interestingly,
despite the seeming noncrystallographic symmetry/equivalence of the
two sets of ‘ion pairs’, the latter interaction for the second pair is less
clear-cut, albeit still resulting in string formation, the iodine interacting
as well with associated fluorines (I(24)‚‚‚F(21,23), O(22) (x, y-1, z)
3.556(4), 3.746(3), Å). As might be expected, there are also numerous
other ‘contacts’ from diverse atoms to the iodines at longer distances.
The substituted phenyl rings are similarly inclined to the ac face,
contacting peripherally at typical interplanar spacings. Insofar as
intraspecies geometries are concerned, the C-I distances are remark-
ably similar (av. 2.100(9) Å), the two C-I-C angles both very close to
90°.
Construction of simple 1,4-arenediyl bridges between
Pt(II) centers that are not stabilized by intramolecular
coordination has been achieved via the transmetalation
reaction of 1,4-bis(trimethylstannyl)benzene with dichlo-
ro(1,4-cyclooctadiene)platinum(II)29 and the oxidative
addition of 1,4-diiodobenzene to tetrakis(triethylphos-
phine)platinum(0).30 The synthesis of the diplatinum-
(IV) complex 9b using iodine(III) reagents opens a
pathway to Pt(IV) complexes containing the archetypal
1,4-benzenediyl bridge.
Triarylplatinum(IV) chemistry involving hydrocarbyl
groups appears to be limited to the isolation of cis-PtBr-
{2-(PhCH2NdCH2)C6H4-C,N}Ph2(SMe2), formed on the
oxidative addition of 2-(benzylimino)bromobenzene to
(27) Rashidi, M.; Fakhroeian, Z.; Puddephatt, R. J . J . Organomet.
Chem. 1990, 406, 261.
(28) Grushin, V. V. Acc. Chem. Res. 1992, 25, 529.
(29) Mueller, W. D.; Brune, H. A. Chem. Ber. 1986, 119, 759.
(30) (a) Manna, J .; Kuehl, C. J .; Whiteford, J . A.; Stang, P. J .
Organometallics 1997, 16, 1897. (b) Gardinier, J . R.; Cle´rac, R.; Gabba¨ı,
J . Chem. Soc., Dalton Trans. 2001, 3453.

Reactivity of Diaryliodine(III) Triflates
Organometallics, Vol. 23, No. 14, 2004 3473
cis-PtPh2(SMe2)2.9h The facile synthesis and stability at
(bpy) and M(C4H8)(bpy) (M ) Pd, Pt), indicating an
absence of reactivity, thus consistent with the key role
of the electrophilic iodine(III) center in the transfer of
Ar+ to these d8 metal complexes.
ambient temperature of PtIPh3(But bpy) (11) indicate
2
that it should be possible to develop an extensive
chemistry of triarylplatinum(IV) species in the absence
of intramolecular coordination by the aryl groups.
Transfer of aryl cations from [Ar2I]+ to organic and
organometallic reagents containing a nucleophilic center
most likely occurs via nucleophilic attack at the iodine-
(III) center followed by Nu-Ar bond formation and
release of ArI.4 In the present case, the nucleophilic
metal centers are Pd(II) and Pt(II). Transfer of Ar+ to
metal(II) centers reported here has led us to examina-
tion of the reactivity of phenyl triflate toward PtMe2-
Su p p or tin g In for m a tion Ava ila ble: Atomic parameters,
bond distances and angles, and crystallographic details for 2b,
5b, and [IPh(C6H4-4-I)][OTf], CIF files for the three structure
determinations, projections of the structure of [IPh(C6H4-4-I)]-
[OTf], and a HMBC NMR spectrum for 9b. This material is
available free of charge via the Internet at http://pubs.acs.org.
OM040023C