Reaction of vinyl chloride with cationic palladium acyl complexes

Article abstract of DOI:10.1021/om021028h

Vinyl chloride (VC) reacts with the cationic Pd complexes [L₂Pd(Me)(CO)][B(C₆F₅)₄] (3a-d; L₂ = Me₂bipy, ^tBu₂bipy, dppp, dmpe) and [L₂Pd{C(=O)Me}(CO)][B(C₆F₅)₄] (4a-d) by 2,1-insertion of L₂Pd{C(=O)Me}(VC)⁺ intermediates to yield the O-chelated products [L₂Pd{CHClCH₂C(=O)Me}][B(C₆F₅)₄ ] (5a-d). 5a-d were characterized by NMR spectroscopy, and the molecular structures of 5a and 5b·CH₂Cl₂ were determined by X-ray crystallography. The VC 2,1-insertion regiochemistry is favored in part because the alternative L₂Pd{CH₂CHClC(=O)Me}⁺ 1,2-insertion products would be destabilized by placement of the electron-withdrawing Cl and acyl substituents on the same carbon. In contrast to analogous nonhalogenated L₂Pd{CHRCHR′C(=O)Me}⁺ species, 5a,c do not further react with CO, due to the stability of the chelate ring and the low migratory aptitude of the -CHClCH₂C(=O)Me group.

Full text of DOI:10.1021/om021028h

1878
Organometallics 2003, 22, 1878-1887
Rea ction of Vin yl Ch lor id e w ith Ca tion ic P a lla d iu m Acyl
Com p lexes
Han Shen and Richard F. J ordan*
Department of Chemistry, The University of Chicago, 5735 South Ellis Avenue,
Chicago, Illinois 60637
Received December 20, 2002
Vinyl chloride (VC) reacts with the cationic Pd complexes [L2Pd(Me)(CO)][B(C6F5)4] (3a -
d ; L2 ) Me2bipy, tBu2bipy, dppp, dmpe) and [L2Pd{C(dO)Me}(CO)][B(C6F5)4] (4a -d ) by 2,1-
insertion of L2Pd{C(dO)Me}(VC)+ intermediates to yield the O-chelated products [L2Pd-
{CHClCH2C(dO)Me}][B(C6F5)4] (5a -d ). 5a -d were characterized by NMR spectroscopy,
and the molecular structures of 5a and 5b‚CH2Cl2 were determined by X-ray crystallography.
The VC 2,1-insertion regiochemistry is favored in part because the alternative L2Pd{CH2-
CHClC(dO)Me}+ 1,2-insertion products would be destabilized by placement of the electron-
withdrawing Cl and acyl substituents on the same carbon. In contrast to analogous
nonhalogenated L2Pd{CHRCHR′C(dO)Me}+ species, 5a ,c do not further react with CO, due
to the stability of the chelate ring and the low migratory aptitude of the -CHClCH2C(dO)-
Me group.
Sch em e 1
In tr od u ction
The alternating copolymerization of carbon monoxide
and olefins catalyzed by late-transition-metal catalysts
has been studied extensively.1 In these reactions, cat-
ionic L2PdR+ species which are stabilized by neutral
bidentate N-donor or P-donor ligands undergo alternat-
ing CO and olefin insertions to produce polyketones
(Scheme 1). X-ray crystallographic determinations and
NMR and IR studies have shown that the L2PdCH2-
CH2C(dO)R+ intermediates adopt O-chelated struc-
tures.1,2
To date, studies of olefin/CO copolymerization have
focused on nonfunctionalized olefins, including ethylene,
propylene, styrene,1 strained cyclic olefins such as
norbornene,3 and allene.4 Studies of the copolymeriza-
tion of CO with functionalized olefins may lead to
functionalized polyketones and may also provide useful
insights to the problem of designing catalysts for the
homo- or copolymerization of polar monomers by inser-
tion mechanisms.5 Copolymerizations of CO with re-
motely functionalized CH2dCH(CH2)nX monomers (X )
OAc, fluorophenyl, OH, CO2H, epoxide, phenol, etc.)
have been reported by several groups,6 and insertion
reactions of acrylates, vinyl acetate, and methyl vinyl
ketone with cationic Pd acyl species have also been
studied.2d,e,g,h,7,8 Here we describe studies of the reaction
of L2Pd{C(dO)Me}+ complexes with vinyl chloride (VC),
which are directed toward the long-term goal of prepar-
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10.1021/om021028h CCC: $25.00 © 2003 American Chemical Society
Publication on Web 03/20/2003

Reaction of Vinyl Chloride with Pd Acyl Complexes
Organometallics, Vol. 22, No. 9, 2003 1879
ing new materials by insertion polymerization or copo-
lymerization of CH2dCHX monomers using metal cata-
lysts. Free radical copolymerization of VC and CO yields
a random copolymer composed of VC and acrylyl chlo-
ride units (i.e., -CH2CH(COCl)- instead of -CH2-
CHClC(dO)-). The pendant acyl chloride groups are
formed by the rearrangement shown in eq 1.9
We showed previously that VC reacts with (C5R5)2-
ZrR+, (C5Me4SiMe2NtBu)TiR+, (Me2bipy)PdR+, (salicy-
laldiminato)Ni(Ph)(PPh3), and other early- and late-
metal alkyl species by net 1,2-insertion and â-Cl
elimination to produce M-Cl products and the corre-
sponding CH2dCHR olefin.10 Similarly, Wolczanski
reported that (tBu3SiO)3TaH2 reacts with VC by 1,2-
insertion/â-Cl elimination to afford (tBu3SiO)3TaHCl
and ethylene, and Caulton showed that Cp2ZrHCl reacts
with vinyl fluoride in an analogous manner. More
recently, Boone found that VC terminates {2,6-(o-tol-
NdCMe)2-pyridine}FeCl2/MAO-catalyzed ethylene po-
lymerization by 1,2 insertion/â-Cl elimination, and Sen
observed that vinyl bromide reacts with {ArNdC(Me)C-
(Me)dNAr}PdMe+ (Ar ) 2,6-iPr2-C6H3) by 1,2-insertion/
â-Br elimination.11 The fast â-Cl elimination of LnMCH2-
CHClR species precludes VC homopolymerization by
conventional olefin polymerization catalysts. We envi-
sioned that MCH2CHClC(dO)R+ intermediates formed
by 1,2-insertion of VC into a metal-acyl bond would be
stabilized against â-Cl elimination by O-chelation. In
fact, we have found that L2Pd{C(dO)Me}+ species react
with VC by 2,1-insertion.
F igu r e 1. (a) Observed and (b) calculated molecular ion
envelopes from ESI-MS spectra of the {(Me2bipy)PdMe}2-
(µ-Cl)+ cation of 2a .
diene) from (cod)Pd(Me)Cl with the L2 ligand (eq 2).12
Resu lts a n d Discu ssion
Gen er a tion of [{L2P d Me}2(µ-Cl)][B(C6F 5)4] (2a -
d ). Neutral L2Pd(Me)Cl complexes (1a -d ; L2 ) 4,4′-
Me2-2,2′-bipyridine (Me2bipy), 4,4′-tBu2-2,2′-bipyridine
(tBu2bipy), 1,3-bis(diphenylphosphino)propane (dppp),
1,2-bis(dimethylphosphino)ethane (dmpe)), which are
precursors to L2Pd{C(dO)Me}+ acyl cations, are pre-
pared in high yield by displacing cod (cod ) cycloocta-
The R2bipy ligands were chosen to enable comparison
of Pd-acyl reactivity with (R2bipy)Pd-Me+.10 The dppp
ligand was chosen because (dppp)PdII systems are
among the most active olefin/CO copolymerization cata-
lysts known.1,13 In contrast, (dmpe)Pd{C(dO)Me}+ spe-
cies exhibit relatively high barriers for olefin insertion
and therefore may allow observation of intermediates
in reactions with VC.14
The reaction of 1a -d with 0.5 equiv of [Li(Et2O)2.4]-
[B(C6F5)4] in CD2Cl2 (23 °C, 1 min) quantitatively yields
the dinuclear monocationic complexes [{L2PdMe}2(µ-Cl)]-
[B(C6F5)4] (2a -d ; Scheme 2). Complexes 2a -d form by
initial Cl- abstraction from 1a -d to yield L2PdMe+,
which is trapped by the remaining 0.5 equiv of 1a -d
by Cl bridging. The 1H NMR spectra of 2:1 and 1:1
mixtures of 1a -d and [Li(Et2O)2.4][B(C6F5)4] in CD2Cl2
are very similar and are consistent with Cs symmetry
at each Pd unit. The positive ion electrospray mass
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1880 Organometallics, Vol. 22, No. 9, 2003
Shen and J ordan
Sch em e 2
F igu r e 2. (a) Observed and (b) calculated molecular ion
envelopes from ESI-MS spectra of the {(dppp)PdMe}2(µ-
Cl)+ cation of 2c.
reactions of 2a -d with CO and VC are summarized in
Scheme 2. Exposure of 2a ,b/[Li(Et2O)2.4][B(C6F5)4] mix-
tures to low CO pressure (60 mm) at -78 °C for 5 min
yields the CO adducts [(R2bipy)Pd(Me)(CO)][B(C6F5)4]
(3a ,b). If higher CO pressure is used, the CO insertion
products 4a ,b start to form. Similarly, the reaction of
2c,d /[Li(Et2O)2.4][B(C6F5)4] mixtures with CO (1 atm)
at -78 °C yields CO adducts 3c,d . Complexes 3a -d are
also formed directly by the reaction of 1a -d and [Li-
(Et2O)2.4][B(C6F5)4] in the presence of CO at -78 °C. The
reaction of 2a -d /[Li(Et2O)2.4][B(C6F5)4] mixtures with
1 atm of CO at 23 °C rapidly yields the acyl cations [L2-
Pd{C(dO)Me}(CO)][B(C6F5)4] (4a -d ). 4a -c are stable
at 23 °C for hours, but 4d decomposes rapidly under
these conditions.
spectra (ESI-MS) of 2a -d exhibit parent ion peaks with
isotope distributions that match calculated patterns;
representative examples are shown in Figures 1 and 2.15
Analogous incomplete halide abstraction and dinuclear
cation formation were observed in the reaction of {ArNd
C(R)C(R)dNAr}Pd(Me)Cl (R ) Me, H; Ar ) 2,6-iPr2-
C6H3) with Na[B{3,5-(CF3)2-C6H3}4].16
Complexes 2a -c are stable in CD2Cl2 for several
hours at 23 °C, while 2d decomposes within 5 min under
these conditions and therefore was stored at -78 °C.
The Et2O released from [Li(Et2O)2.4][B(C6F5)4] does not
compete with 1a -d for the vacant site on the “L2PdMe+”
cation generated by Cl- abstraction from 1a -d .17
However, stronger Lewis bases displace 1a -d from 2a -
d , leading, in the presence of 0.5 equiv of [Li(Et2O)2.4]-
[B(C6F5)4], to clean formation of L2Pd(Me)(base)+ spe-
cies.18
The NMR spectra of the cations of 3c,d and 4c,d are
nearly identical to those of the corresponding B{3,5-
(CF3)2-C6H3}4- salts.14,19 For 3a ,b, the Pd-Me 1H NMR
resonances appear at δ 1.30 and 0.98, respectively, and
the Pd-CO 13C NMR resonances both appear at δ 176.0.
These data are very similar to those reported for (bipy)-
Pd(Me)(CO)+ (1H, δ 1.49; 13C, δ 176.0)7 and (phen)Pd-
(Me)(CO)+ (1H, δ 1.66; 13C, δ 176.3).7,20 Key NMR data
1
for 4a ,b include PdC(dO)Me H NMR resonances at δ
2.81 and 2.82, respectively, and PdC(dO)Me 13C NMR
resonances at δ 218.9 and 218.6. The Pd-CO 13C NMR
resonances for 4a ,b appear at δ 172.5. These data are
similar to results for (phen)Pd{C(dO)Me}(CO)+ (1H, δ
2.92; 13C, δ 216.5, 173.0).7,20
Gen er a tion of [L2P d (Me)(CO)][B(C6F 5)4] (3a -d )
a n d [L2P d {C(dO)Me}(CO)] [B(C6F 5)4] (4a -d ). The
(15) (a) Piquet, C.; Bernardinelli, G.; Hopfgarter, G. Chem. Rev.
1997, 97, 2005. (b) Colton, R.; Agostino, A. O.; Traeger, J . C. Mass
Spectrom. Rev. 1995, 14, 79. (c) Henderson, W.; Nicholson, B. K.;
McCaffrey, L. J . Polyhedron 1998, 17, 4291.
Rea ction of 3a -d a n d 4a -d w ith VC. NMR studies
show that 3a -d react with VC above -40 °C to yield
the O-chelated insertion products [L2Pd{CHClCH2C(d
O)Me}][B(C6F5)4] (5a -d ; Scheme 2). This reaction pro-
ceeds by VC-induced CO insertion to yield the interme-
(16) Tempel, D. J .; J ohnson, L. K.; Huff, R. L.; White, P. S.;
Brookhart, M. J . Am. Chem. Soc. 2000, 122, 6686.
(17) The 1H and 13C NMR spectra of in situ generated 2a -d at -70
°C contain only one set of Et2O signals which are slightly different
from those of free Et2O under the same conditions, probably due to
fast exchange of Li+-OEt2 and free Et2O.
(18) For discussions of methods of generating L2PdR+ species, see
ref 1d and: Ittel, S. D.; J ohnson, L. K.; Brookhart, M. Chem. Rev. 2000,
100, 1169.
(19) Shultz, C. S.; Ledford, J .; DeSimone, J . M.; Brookhart, M. J .
Am. Chem. Soc. 2000, 122, 6351.
(20) Rix, F. C.; Brookhart, M. J . Am. Chem. Soc. 1995, 117, 1137.

Reaction of Vinyl Chloride with Pd Acyl Complexes
Organometallics, Vol. 22, No. 9, 2003 1881
diate acyl VC complex L2Pd{C(dO)Me}(VC)+ (not
observed), which in turn undergoes VC 2,1-insertion.
Similarly, 4a -d react with VC above -40 °C to yield
5a -d . These reactions occur in the presence of LiCl and
free Et2O; therefore, 5a -d can be synthesized on a
preparative scale in a one-pot procedure by sequential
treatment of 1a -d with [Li(Et2O)2.4][B(C6F5)4], CO, and
VC. Complexes 5a -d are isolated as analytically pure
solids by filtration to remove LiCl and vacuum drying
to remove Et2O.
Sp ectr oscop ic Stu d ies of [L2P d {CHClCH2C(dO)-
Me}][B(C6F 5)4] (5a -d ). NMR studies establish that
5a -d adopt chelated structures with R-Cl substituents.
For 5a , the -CH2- 1H NMR resonances are easily
identified at δ 3.71 and 3.35 because they exhibit large
1H-1H geminal coupling constants (J ) 20 Hz) char-
acteristic of a CH2 unit in a five-membered ring.21 The
δ 3.71 resonance exhibits vicinal coupling with a reso-
nance at δ 4.34, which enables assignment of the latter
as the -CHCl- resonance. This assignment of the
-CHCl- resonance was confirmed by DEPT and HMQC
experiments. The NOESY spectrum of 5a (Figure 3a)
exhibits a cross-peak between the -CHCl- resonance
and a Me2bipy ortho-H resonance (δ 8.39), which
establishes that the -CHCl- unit is R to Pd. Similarly,
for 5b, the -CH2- (δ 3.71, 3.37) and -CHCl- (δ 4.35)
1H NMR resonances are identified by multiplicity
analysis and DEPT and HMQC experiments. The
NOESY spectrum of 5b (Figure 3b) exhibits a cross-peak
t
between the -CHCl- resonance and a Bu2bipy ortho-H
resonance (δ 8.46), which, following the same argument
for 5a , establishes that the -CHCl- unit is R to Pd.
1
The H NMR spectra of 5c and 5d are complicated
by 1H-31P coupling, and assignments of the -CHClCH2-
resonances were made with the aid of 13C NMR data.
For 5c, the -CHCl- 13C resonance, which is the only
aliphatic CH resonance in the spectrum, is identified
at δ 69.2 by a DEPT-135 experiment (Figure 4a,b). This
resonance appears as a doublet of doublets due to
coupling to 31P. The J PC values (113 and 8 Hz) are in
2
2
the range for J PC(trans) and J PC(cis) values for square-
planar (R3P)2Pd(R)(L)+ species and thus establish that
the -CHCl- unit is R to Pd. If the -CHCl- unit were
â to Pd, much smaller J PC values would be expected.22
1
The PdCHCl- resonance is correlated with a H NMR
resonance at δ 3.16 in the HMQC spectrum, which is
thus assigned to PdCHCl-. The 1H PdCHCl- resonance
exhibits a cross-peak with a PPh resonance in the
NOESY spectrum, which confirms the PdCHClCH2-
connectivity (Figure 5a). For 5d , the -CHCl- 13C
resonance is identified at δ 59.8 (J PC ) 120, 2 Hz) by
the DEPT-135 spectrum (Figure 4c,d). This resonance
F igu r e 3. Partial NOESY spectra of [L2Pd{CHClCH2C-
(dO)Me}][B(C6F5)4] complexes: (a) complex 5a ; (b) complex
5b. In each case the correlation between the -CHCl and
ortho R2bipy resonances establishes that the Cl is R to Pd.
The coordination of the acyl oxygen in 5a -d is
established by the presence of low-field carbonyl 13C
NMR resonances (δ 234-238), which are shifted down-
field from the free ketone region (δ 206-218),23 as
observed previously for analogous non-halogen-substi-
tuted Pd chelate complexes (δ 232-245).2,7,20,24
Rea ctivity of [L2P d {CHClCH2C(dO)Me}][B(C6-
F 5)4] (5a -d ). Complexes 5a -d are remarkably stable.
These compounds are stable in C6D5Cl solvent up to 85
1
is correlated with a H NMR resonance at δ 3.98 in the
HMQC spectrum, and the latter is correlated with PMe
resonances at δ 1.69 and 1.66 in the NOESY spectrum
(Figure 5b), which establishes that the -CHCl- unit
is R to Pd.
(21) For example, geminal J HH values are -21.5 Hz for 4-cyclopen-
tene-1,3-dione and -22.3 Hz for fluorene: Lambert, J . B.; Shurvell,
H. F.; Lightner, D. A.; Cooks, R. G. Organic Structural Spectroscopy;
Prentice-Hall: Englewood Cliffs, NJ , 1998; pp 70-74.
(23) Breitmaier, E.; Voelter, W. Carbon-13 NMR Spectroscopy:
High-Resolution Methods and Applications in Organic Chemistry and
Biochemistry, 3rd ed.; VCH: Weinheim, Germany, 1987.
(24) Markies, B. A.; Verkerk, K. A. N.; Rietveld, M. H. P.; Boersma,
J .; Kooijman, H.; Spek, A. L.; van Koten, G. J . Chem. Soc., Chem.
Commun. 1993, 1317.
(22) (a) Mann, B. E.; Taylor; B. F. 13C NMR Data for Organometallic
Compounds; Academic Press: New York, 1981; p 23. (b) For example,
2
for (dppp)Pd{CH2CH2C(dO)Me}+, J PC(trans) ) 89 Hz for CR (2J PC
-
(cis) not observed) and J PC(trans) ) 6 Hz for Câ (2J PC(cis) not
3
observed).14,19

1882 Organometallics, Vol. 22, No. 9, 2003
Shen and J ordan
F igu r e 4. Partial 13C NMR spectra of VC insertion
products: (a) DEPT-135 and (b) 13C{1H} spectra of [(dppp)-
Pd{CHClCH2C(dO)Me}][B(C6F5)4] (5c); (c) DEPT-135 and
(d) 13C NMR spectra of [(dmpe)Pd{CHClCH2C(dO)Me}]-
[B(C6F5)4] (5d ).
°C but decompose to unidentified products above this
temperature. Compounds 5a ,c do not react with CO,
VC, VC/CO mixtures, C2H4, or C2H4/CO mixtures up to
85 °C. Additionally, the thermal decomposition of 5a ,c
above 85 °C is unaffected by these substrates. The
reactions of 5a with VC/CO in the presence of AlCl3,
B(C6F5)3, or PPh3 were also investigated in an attempt
to open the O-chelate ring. However, no insertion of VC
or CO was observed and 5a decomposes to unidentified
products under these conditions.
Molecu la r Str u ctu r e a n d Rea ctivity of 5b. The
molecular structures of 5a and 5b‚CH2Cl2 were deter-
mined by X-ray diffraction. ORTEP views of the (tBu2-
bipy)Pd{CHClCH2C(dO)Me}+ cation of 5b are shown
in Figure 6, and selected metrical parameters are listed
in Table 1. The structure of 5a is very similar to that of
5b and is described in the Supporting Information. The
cation of 5b exhibits square-planar geometry with only
a slight deviation (0.0266 Å) of Pd from the plane
F igu r e 5. Partial NOESY spectra of [L2Pd{CHClCH2C-
(dO)Me}][B(C6F5)4] complexes: (a) complex 5c; (b) complex
5d . In each case the correlation between the -CHCl and
P-R resonances establishes that the Cl is R to Pd.
O-chelated complexes which insert CO (Figures 7-9).
This comparison indicates that the chelate ring of 5b is
unusually tight and suggests that the resistance of 5b
to insertion reactions may reflect a low tendency of this
species to form chelate-opened (tBu2bipy)Pd{CHClCH2C-
(dO)Me}(substrate)+ intermediates.25,26 It should be
t
defined by N(1), N(2), C(19), and O(1). The Bu2bipy
ligand is slightly twisted around the C(5)-C(6) bond
such that the dihedral angle N(1)-C(5)-C(6)-N(2) is
7.9° and C(5) and C(6) deviate from the Pd(1)-N(1)-
N(2) plane by -0.025 and 0.071 Å, respectively. The
â-keto-alkyl chelate ring adopts an envelope conforma-
tion with C(20) and C(21) deviating from the Pd(1)-
O(1)-C(19) plane by 0.642 and 0.321 Å, respectively.
The Pd-O (2.045 Å) and Pd-C (2.001 Å) bond
distances of 5b are at the short end of the ranges
observed for Pd-O distances (2.028-2.155 Å) and Pd-C
distances (2.001-2.068 Å) in analogous nonhalogenated
(25) The insertion of imines into LnPd{C(dO)R}+ species (M ) Pd,
Ni) produces O-chelated LnMCH2N(R′)C(dO)R+ species, which are
resistant to further CO or imine insertion. This lack of reactivity was
ascribed to strong O chelation, which inhibits coordination of sub-
strates. (a) Sen, A. Pure Appl. Chem. 2001, 73, 251. (b) Davis, J . L.;
Arndtsen, B. A. Organometallics 2000, 19, 4657. (c) Cavallo, L. J . Am.
Chem. Soc. 1999, 121, 4238. (d) Kacker, S.; Kim, J . S.; Sen, A. Angew.
Chem., Int. Ed. 1998, 37, 1251. (e) Dghaym, R. D.; Yaccato, K. J .;
Arndtsen, B. A. Organometallics 1998, 17, 4. (f) Davis, J . L.; Arndtsen,
B. A. Organometallics 2000, 19, 4657.

Reaction of Vinyl Chloride with Pd Acyl Complexes
Organometallics, Vol. 22, No. 9, 2003 1883
larly {H(hexyl)C(mim)2}Pd(CHCl2)(CO)+ (mim ) N-me-
thylimidazol-2-yl) does not insert CO but analogous
nonhalogenated {HRC(mim)}Pd(Me)(CO)+ species readily
react to form {HRC(mim)}Pd{C(dO)Me}(CO)+.29 There-
fore, we propose that both the tight chelation and low
migratory aptitude of the -CHClCH2C(dO)Me group
contribute to the low reactivity of 5a -d .
Regioch em istr y of Olefin In ser tion s of P d -Acyl
Com p lexes. Olefin insertions of L2Pd(R)(olefin)+ and
related group 10 metal alkyl species have been inves-
tigated by DFT methods by several groups, and several
factors that influence the regioselectivity of these reac-
tions have been identified.30 Olefin “distortion energies”,
i.e., the energy required to distort the coordinated olefin
from its structure in the olefin complex to that in the
insertion transition state, and steric interactions be-
tween the olefin substituents and the migrating R group
in the transition state both favor 2,1-insertion. On the
other hand, asymmetry in the Pd-olefin bonding in the
olefin complex (i.e., d(Pd-Csubstituted) > d(Pd-Cunsubsti
-
tuted)) and steric interactions between the coordinated
olefin and the ancillary ligand (L2) favor 1,2-insertion.
These same factors are also expected to be important
in olefin insertion of L2Pd{C(dO)R}(olefin)+ species.31
Previous studies show that propylene reacts with
(dppp)Pd{C(dO)R}+ by competitive 2,1- and 1,2-inser-
tions (relative frequency 1:3), which lead to regioirregu-
lar CO/propylene copolymer.1a However, when bulkier
ancillary ligands are used, 1,2-insertion predominates
and more highly regioregular CO/propylene copolymer
is formed; e.g., >99% selectivity for 1,2-insertion is
observed for L2 ) 1,3-bis(diisopropylphosphino)pro-
pane).32,33 Our results show that (dppp)Pd{C(dO)Me}-
(VC)+ and the sterically less crowded R2bipy and dmpe
analogues undergo exclusive VC 2,1-insertion, yielding
L2Pd{CHClCH2C(dO)Me)}+ products. VC is similar in
size to propylene.34 However, the presence of the
F igu r e 6. ORTEP views of the (tBu2bipy)Pd{CHClCH2C-
(dO)Me}+ cation of 5b. H atoms are omitted for clarity.
Ta ble 1. Selected Bon d Len gth s (Å) a n d An gles
(d eg) for 5b‚CH2Cl2
Pd(1)-N(1)
Pd(1)-O(1)
C(19)-C(20)
C(20)-C(21)
C(21)-O(1)
2.013(3)
2.045(3)
1.521(4)
1.472(4)
1.241(4)
Pd(1)-N(2)
Pd(1)-C(19)
C(19)-Cl(1)
C(21)-C(22)
2.076(3)
2.001(3)
1.819(3)
1.473(5)
N(1)-Pd(1)-N(2)
C(13)-Pd(1)-N(1)
N(1)-Pd(1)-O(1)
O(1)-Pd(1)-N(2)
O(1)-C(15)-C(14)
80.2(1) C(15)-O(1)-Pd(1)
99.4(1) C(13)-Pd(1)-O(1)
177.9(1) C(13)-Pd(1)-N(2)
97.8(1) O(1)-C(15)-C(16)
115.4(2)
82.6(1)
179.6(2)
120.6(3)
(27) (a) Axe, F. U.; Marynick, D. S. J . Am. Chem. Soc. 1988, 110,
3728. (b) Koga, N.; Morokuma, K. J . Am. Chem. Soc. 1986, 108, 6136.
(c) Garrou, P. E.; Heck, R. F. J . Am. Chem. Soc. 1976, 98, 4115. (d)
Blake, D. M.; Winkelman, A.; Chung, Y. L. Inorg. Chem. 1975, 14, 1326.
(e) Calderazzo, F.; Noack, K. Coord. Chem. Rev. 1966, 1, 118.
(28) Shen, H.; J ordan, R. F. Unpublished results.
118.1(3) C(16)-C(15)-C(14) 121.3(3)
C(15)-C(14)-C(13) 110.8(3) C(14)-C(13)-Cl(2)
C(14)-C(13)-Pd(1) 107.6(2) Cl(2)-C(13)-Pd(1)
109.4(3)
108.0(2)
(29) Shen, H.; Burns, C. T.; J ordan, R. F. Unpublished results.
(30) (a) Michalak, A.; Ziegler, T. J . Am. Chem. Soc. 2001, 123, 12266.
(b) Michalak, A.; Ziegler, T. Organometallics 1999, 18, 3998. (c)
Michalak, A.; Ziegler, T. Organometallics 2000, 19, 1850. (d) Deubel,
D. V.; Ziegler, T. Organometallics 2002, 21, 4432. (e) Deubel, D. V.;
Ziegler, T. Organometallics 2002, 21, 1603. (f) Philipp, D. M.; Muller,
R. P.; Goddard, W. A., III; Storer, J .; McAdon, M.; Mullins, M. J . Am.
Chem. Soc. 2002, 124, 10198. (g) von Schenck, H.; Stro¨mberg, S.;
Zetterberg, K.; Ludwig, M.; Åkermark, B.; Svensson, M. Organome-
tallics 2001, 20, 2813.
(31) See ref 25c and: (a) Margl, P.; Ziegler, T. J . Am. Chem. Soc.
1996, 118, 7337. (b) Margl, P.; Zielger, T. Organometallics 1996, 15,
5519.
(32) Batistini, A.; Consiglio. G.; Suter, U. W. Angew. Chem., Int.
Ed. Engl. 1992, 31, 303.
noted, however, that neither the short Pd-O nor the
short Pd-C bond alone can explain the low reactivity
of 5b. For example, (bipy)Pd{C7H10C(dO)Me}+ (entry
2, Figure 7) has a slightly shorter Pd-O bond than 5b
but readily inserts CO (1 atm) at -30 °C. Similarly,
{Ph2PNHC(O)Me}Pd{CH2CH2C(dO)Me}+ (entry 3)
and {o-(diphenylphosphino)-N-benzaldimine}Pd{CH2-
CH2C(dO)CH2CH2C(dO)Me}+ (entry 8) exhibit essen-
tially the same Pd-C bond distances as 5b, but both
are active ethylene/CO copolymerization catalysts. A
second factor that likely influences the reactivity of
5a -d is the R-Cl substituent, which is expected to
strengthen the Pd-C bond and reduce the nucleophilic
character and migratory aptitude of the Pd-CHClCH2C-
(dO)Me group. It is well established that electron-
withdrawing substituents inhibit CO insertion into
M-alkyl and M-aryl bonds.27 For example, 3c readily
inserts CO but (dppp)Pd(n-C3F7)(CO)+ does not.28 Simi-
(33) Similarly, sterically open L2Pd{C(dO)Me)+ (L2 ) phen, bipy,
bisoxazoline, etc.) species react with styrene by 2,1-insertion, whereas
the bulky acyl complex {(R,S)-BINAPHOS}Pd{C(dO)Me}+ ((R,S)-
BINAPHOS ) (R,S)-2-(diphenylphosphino)-1,1′-binaphthalen-2′-yl 1,1′-
binaphthalene-2,2′-diyl phosphite) undergoes exclusive styrene 1,2-
insertion in CO/styrene copolymerization: Nozaki, K.; Komaki, H.;
Kawashima, Y.; Hiyama, T.; Matsubara, T. J . Am. Chem. Soc. 2001,
123, 534 and references therein.
2
2
(34) The Csp -C distance (1.50 Å) is shorter than the Csp -Cl
distance (1.73 Å), but the van der Waals radius of CH3 (2.0 Å) is larger
than that of Cl (1.8 Å). (a) March, J . Advanced Organic Chemistry:
Reactions, Mechanisms, and Structure, 3rd ed.; Wiley: New York, 1985.
(b) Huheey, J . E.; Keiter, E. A.; Keiter, R. L. Inorganic Chemistry:
Principles of Structure and Reactivity, 4th ed.; HarperCollins: New
York, 1993. (c) Bondi, A. J . Phys. Chem. 1964, 68, 441.
(26) Pd(II)-catalyzed copolymerization of ethylene and acrylates is
inhibited by O chelation of the ester group of the acrylate: Mecking,
S.; J ohnson, L. K.; Wang, L.; Brookhart, M. J . Am. Chem. Soc. 1998,
120, 888.

1884 Organometallics, Vol. 22, No. 9, 2003
Shen and J ordan
F igu r e 7. Crystallographically characterized O-chelated L2PdCHRCHR′C(dO)R′′+ complexes which insert CO. Pd-O
and Pd-C distances are compared in Figures 8 and 9.
acetate, for which exclusive 2,1-insertion has been
observed.2d,e,g,h,7,8
Con clu sion s
Cationic L2Pd{C(dO)Me}+ acyl species (L ) R2bipy,
dppp, dmpe) undergo VC 2,1-insertion to yield the
O-chelated L2Pd{CHClCH2C(dO)Me}+ complexes 5a -
d . The 2,1-regiochemistry is favored in part because the
alternative 1,2-insertion products would be destabilized
by placement of the electron-withdrawing Cl and acyl
substituents on the same carbon. In contrast to analo-
gous nonhalogenated L2Pd{CH2CH2C(dO)R}+ species,
5a -d do not react with CO, due to the stability of the
chelate ring and the low migratory aptitude of the
-CHClCH2C(dO)Me group.
F igu r e 8. Pd-O bond distances of O-chelated L2PdCHR-
CHR′C(dO)R′′+ complexes. Entry assignments are given
in Figure 7: entry 9, 5a ; entry 10, 5b.
Exp er im en ta l Section
Gen er a l P r oced u r es. All manipulations were performed
using drybox or Schlenk techniques under a nitrogen atmo-
sphere or on a high-vacuum line, unless otherwise indicated.
Solvents were distilled from appropriate drying/deoxygenating
agents (Et2O, sodium benzophenone ketyl; CH2Cl2 and C6H5-
Cl, CaH2; CD2Cl2 and C6D5Cl, P4O10). Pentane and benzene
were purified by passage through columns of activated alumina
and BASF R3-11 oxygen removal catalyst. Nitrogen was
purified by passage through columns containing activated
molecular sieves and Q-5 oxygen scavenger. [Li(Et2O)n]-
[B(C6F5)4] was provided by Boulder Scientific, and both were
used as received. The Et2O content of the [Li(Et2O)n][B(C6F5)4]
salt was determined by 1H NMR with C6Me6 as internal
standard (n ) 2.4 or 2.8, depending on the batch from the
supplier). (cod)Pd(Me)Cl,12a tBu2bipy,35 (dppp)Pd(Me)Cl (1c),12b
and (dmpe)Pd(Me)Cl (1d )12c were prepared by literature
procedures. All other chemicals were purchased from Aldrich
and used without further purification. Elemental analyses
were performed by Midwest Microlab or Galbraith Laborato-
ries, Inc.
F igu r e 9. Pd-C bond distances of O-chelated L2PdCHR-
CHR′C(dO)R′′+ complexes. Entry assignments are given
in Figure 7: entry 9, 5a ; entry 10, 5b.
electron-withdrawing Cl substituent in VC provides an
additional electronic driving force for 2,1-insertion,
because the alternative 1,2-insertion product L2Pd{CH2-
CHClC(dO)R)}+ would be destabilized by placement of
the electron-withdrawing Cl and acyl substituents on
the same (â) carbon. Similar electronic effects may be
important in the reactions of L2Pd{C(dO)R}+ species
with methyl acrylate, methyl vinyl ketone, and vinyl
(35) Belser, P.; Zelewsky, A. Helv. Chim. Acta 1980, 63, 1675.

Reaction of Vinyl Chloride with Pd Acyl Complexes
Organometallics, Vol. 22, No. 9, 2003 1885
NMR spectra were recorded on Bruker DMX-500 or DRX-
400 spectrometers, in Teflon-valved tubes, at 23 °C unless
(s, 3H, PdMe).36 13C{1H} NMR (CD2Cl2, -70 °C): δ 156.0,
152.1, 151.9, 151.6, 147.8, 147.3, 127.4, 127.2, 123.5, 122.4,
21.4 (bipy-Me), 21.3 (bipy-Me), 3.1 (PdMe). Positive ion ESI-
MS: m/z 645.0, {(Me2bipy)PdMe}2(µ-Cl)+.
1
otherwise indicated. H and 13C chemical shifts are reported
vs SiMe4 and were determined by reference to residual 1H and
13C solvent signals. 11B chemical shifts are referenced to
external Et2O‚BF3. 19F chemical shifts are reported relative
to CFCl3. 31P chemical shifts are reported vs H3PO4 (85%).
Coupling constants are reported in Hz.
Gen er a tion of [{(tBu 2bip y)P d Me}2(µ-Cl)][B(C6F 5)4] (2b).
This compound was generated quantitatively from 1b (10 mg,
0.024 mmol) and [Li(Et2O)2.8][B(C6F5)4] (21 mg, 0.024 mmol)
using the procedure for 2a . 1H NMR (CD2Cl2, -70 °C): δ 8.78
(d, J ) 5, 1H), 8.35 (d, J ) 5, 1H), 8.08 (s, 1H), 8.05 (s, 1H),
7.54 (d, J ) 5, 1H), 7.50 (d, J ) 5, 1H), 1.36 (s, 9H, CMe3),
1.35 (s, 9H, CMe3), 0.92 (s, 3H, PdMe). 13C{1H} NMR (CD2Cl2,
-70 °C): δ 163.9, 163.6, 156.3, 152.3, 148.0, 147.4, 123.9,
123.8, 119.8, 118.7, 35.3 (CMe3), 35.2(CMe3), 29.6 (CMe3), 29.5
(CMe3), 3.1 (PdMe). Positive ion ESI-MS: m/z 813.2, {(tBu2-
bipy)PdMe}2(µ-Cl)+.
Gen er a t ion of [{(d p p p )P d Me}2(µ-Cl)][B(C6F 5)4] (2c).
This compound was generated quantitatively from 1c (10 mg,
0.018 mmol) and [Li(Et2O)2.4][B(C6F5)4] (15 mg, 0.018 mmol)
using the procedure for 2a . 1H NMR (CD2Cl2, -70 °C): δ 7.54-
7.21 (m, 20H, Ph), 2.48 (m, 2H, PCH2), 2.33 (m, 2H, PCH2),
1.67 (m, 2H, CH2), 0.47 (dd, J ) 7, 3, 3H, PdMe). 13C{1H} NMR
(CD2Cl2, -70 °C): δ 133.2 (d, J ) 11), 133.0 (d, J ) 11), 131.1
(s), 130.9 (d, J ) 36), 130.2 (s), 129.0 (d, J ) 55), 128.5 (d, J )
11), 128.2 (d, J ) 9), 28.3 (dd, J ) 32, 9, PCH2), 26.9 (d, J )
21, PCH2), 18.0 (s, CH2), 16.8 (d, J ) 94, PdMe). 31P{1H} NMR
(CD2Cl2, -70 °C): δ 28.8 (d, J ) 49), -4.1 (d, J ) 49). Positive
ion ESI-MS: m/z 1101.1, {(dppp)PdMe}2(µ-Cl)+.
The NMR spectra of cationic complexes contain signals for
the free B(C6F5)4 anion. 13C{1H} NMR (CD2Cl2): δ 148.5 (d,
-
J ) 242), 137.0 (d, J ) 247), 135.6 (d, J ) 244), 123.1 (br,
C
ipso). 19F NMR (CD2Cl2): δ -132.1 (br s, 8F, Fortho), -161.3 (t,
J ) 21, 4F, Fpara), -165.2 (t, J ) 17, 8F, Fmeta). 19F NMR (CD2-
Cl2, -70 °C): δ -132.5 (br s, 8F, Fortho), -161.7 (t, J ) 21, 4F,
F
para), -164.9 (t, J ) 17, 8F, Fmeta). 11B NMR (CD2Cl2): δ -16.1
(br s). 11B NMR (CD2Cl2, -70 °C): δ -15.8 (br s).
Unless otherwise noted, Et2O does not coordinate to the Pd
species described herein and exhibits NMR spectra charac-
1
teristic of free Et2O. H NMR (CD2Cl2): δ 3.43 (q, J ) 7, 4H),
1.15 (t, J ) 7, 6H). 13C{1H} NMR (CD2Cl2): δ 66.0 (s), 15.5 (s).
1H NMR (CD2Cl2, -70 °C): δ 3.35 (q, J ) 7, 4H), 1.09 (t, J )
7, 6H). 13C{1H} NMR (CD2Cl2, -70 °C): δ 65.7 (s), 15.2 (s).
Electrospray mass spectra were recorded on freshly pre-
pared samples (ca. 1 mg/mL in CH2Cl2) using an Agilent 1100
LC-MSD spectrometer incorporating a quadrupole mass filter
with a m/z range of 0-3000. A 5 µL sample was injected by
flow injection using an autosampler. Purified nitrogen was
used as both the nebulizing and drying gas. Typical instru-
mental parameters: drying gas temperature 350 °C, nebulizer
pressure 35 psi, drying gas flow 12.0 L/min, fragmentor voltage
70 V.
Gen er a t ion of [{(d m p e)P d Me}2(µ-Cl)][B(C6F 5)4] (2d ).
This compound was generated quantitatively from 1d (10 mg,
0.033 mmol) and [Li(Et2O)2.4][B(C6F5)4] (28 mg, 0.033 mmol)
using the procedure for 2a . 2d decomposes within 5 min at 23
°C, and the NMR tube was maintained at -78 °C until further
1
(Me2bip y)P d (Me)Cl (1a ). A Schlenk flask was charged
with (cod)Pd(Me)Cl (268 mg, 1.01 mmol) and Me2bipy (186 mg,
1.01 mmol), and CH2Cl2 (15 mL) was added by cannula. A
yellow precipitate formed rapidly. The reaction mixture was
stirred at 23 °C for 2 h, and the volatiles were removed under
vacuum. The solid was washed with ether (3 × 10 mL) to yield
(Me2bipy)Pd(Me)Cl as a pale yellow solid (307 mg, 89%). 1H
NMR (CD2Cl2): δ 8.91 (d, J ) 5, 1H), 8.44 (d, J ) 6, 1H), 7.91
(s, 1H), 7.85 (s, 1H), 7.35 (d, J ) 6, 1H), 7.32 (d, J ) 5, 1H),
2.51 (s, 3H, bipy-Me), 2.50 (s, 3H, bipy-Me), 0.83 (s, 3H,
PdMe). 13C{1H} NMR (CD2Cl2): δ 157.0, 153.1, 151.2, 151.0,
148.6, 148.4, 127.5, 127.3, 123.6, 122.3, 21.7 (bipy-Me), 21.6
(bipy-Me), -2.0 (PdMe). Anal. Calcd for C13H15ClN2Pd: C,
45.77; H, 4.43; N, 8.21. Found: C, 45.70; H, 4.63; N, 8.12.
reactions were carried out. H NMR (CD2Cl2, -70 °C): δ 1.92
(m, 2H, CH2), 1.62 (m, 2H, CH2), 1.51 (d, J ) 12, 6H, PMe),
1.40 (d, J ) 9, 6H, PMe), 0.29 (d, J ) 7, 3H, PdMe). 13C{1H}
NMR (CD2Cl2, -70 °C): δ 29.8 (dd, J ) 36, 23, CH2), 23.7 (dd,
J ) 28, 8, CH2), 12.8 (d, J ) 35, PMe), 11.5 (d, J ) 18, PMe),
5.9 (d, J ) 104, PdMe). 31P{1H} NMR (CD2Cl2, -70 °C): δ 42.4
(d, J ) 23), 25.8 (d, J ) 23). Positive ion ESI-MS: m/z 577.0,
{(dmpe)PdMe}2(µ-Cl)+.
Gen er a tion of [(Me2bip y)P d (Me)(CO)][B(C6F 5)4] (3a ).
A valved NMR tube containing a CD2Cl2 solution of 2a and 1
equiv of [Li(Et2O)2.4][B(C6F5)4], generated as described above,
was exposed to CO (60 mm Hg) for 5 min at -78 °C. The NMR
tube was vigorously shaken at -78 °C. A slurry of a fine white
solid in a pale yellow supernatant was obtained. The NMR
tube was maintained at -78 °C until further characterization
and reactions were carried out. The 1H NMR spectrum
established that 3a had formed quantitatively. 1H NMR (CD2-
Cl2, -70 °C): δ 8.41 (d, J ) 5, 1H), 8.37 (d, J ) 6, 1H), 8.23 (s,
1H), 8.22 (s, 1H), 7.52 (d, J ) 6, 1H), 7.46 (d, J ) 5, 1H), 2.55
(s, 3H, bipy-Me), 2.51 (s, 3H, bipy-Me), 1.30 (s, 3H, PdMe).
13C{1H} NMR (CD2Cl2, -70 °C): δ 176.0 (Pd-CO), 156.1,
155.2, 154.0, 152.1, 150.6, 146.0, 128.7, 127.8, 124.0, 123.5,
21.5 (two bipy Me), 4.5 (PdMe); the assignment of the Pd-CO
resonance was confirmed using 13CO.
(tBu 2bip y)P d (Me)Cl (1b). This compound was prepared
t
from Bu2bipy and (cod)Pd(Me)Cl using the procedure for 1a .
Yield: 1.41 g, 89%, pale yellow solid. 1H NMR (CD2Cl2): δ 9.00
(d, J ) 6, 1H), 8.54 (d, J ) 6, 1H), 8.04 (d, J ) 2, 1H), 7.99 (d,
J ) 2, 1H), 7.56 (dd, J ) 6, 2, 1H), 7.52 (dd, J ) 6, 2, 1H), 1.43
(s, 9H), 1.41 (s, 9H), 0.85 (s, 3H, PdMe). 13C{1H} NMR (CD2-
Cl2): δ 163.7, 163.6, 157.3, 153.4, 148.8, 148.6, 124.0, 123.9,
119.6, 118.3, 35.8 (CMe3), 35.7 (CMe3), 30.5 (CMe3), 30.4
(CMe3), -2.0. Anal. Calcd for C19H27ClN2Pd: C, 53.65; H, 6.40;
N, 6.59. Found: C, 53.56; H, 6.58; N, 6.20.
Gen er a tion of [(tBu 2bip y)P d (Me)(CO)][B(C6F 5)4] (3b).
This compound was quantitatively generated from 2b, [Li-
(Et2O)2.4][B(C6F5)4], and CO and handled using the procedures
Gen er a tion of [{(Me2bip y)P d Me}2(µ-Cl)][B(C6F 5)4] (2a ).
A valved NMR tube was charged with 1a (5 mg, 0.015 mmol)
and [Li(Et2O)2.4][B(C6F5)4] (13 mg, 0.015 mmol), and CD2Cl2
(0.5 mL) was added by vacuum transfer. The NMR tube was
briefly warmed to 23 °C and vigorously shaken. A slurry of a
white solid in a pale yellow supernatant formed within 1 min.
The unreacted [Li(Et2O)2.4][B(C6F5)4], free Et2O, and LiCl
coproducts were not removed. The 1H NMR spectrum estab-
lished that 2a had formed quantitatively. Although the product
is stable at 23 °C for several hours, the NMR tube was
maintained at -78 °C until further reactions were carried out.
1H NMR (CD2Cl2, -70 °C): δ 8.76 (d, J ) 5, 1H), 8.33 (d, J )
5, 1H), 7.94 (s, 1H), 7.91 (s, 1H), 7.39 (d, J ) 5, 2H), 7.36 (d,
J ) 5, 2H), 2.50 (s, 3H, bipy-Me), 2.49 (s, 3H, bipy-Me), 0.99
1
for 3a . H NMR (CD2Cl2, -70 °C): δ 8.82 (d, J ) 6, 1H), 8.39
(d, J ) 6, 1H), 8.06 (s, 1H), 8.03 (s, 1H), 7.56 (d, J ) 6, 1H),
7.52 (d, J ) 6, 1H), 1.37 (s, 9H), 1.36 (s, 9H), 0.98 (s, 3H, PdMe).
13C{1H} NMR (CD2Cl2, -70 °C): δ 176.0, 163.9, 163.3, 156.3,
152.3, 148.0, 147.5, 123.9, 123.8, 119.7, 118.6, 35.3 (CMe3), 35.2
(CMe3), 29.6 (CMe3), 29.5 (CMe3), 3.1 (PdMe).
(36) The 1H NMR spectrum of 2a generated from a 2/1 mixture of
1a and [Li(Et2O)2.8][B(C6F5)4] is nearly identical, except that the Me2-
bipy ortho-H resonances are shifted slightly downfield to δ 8.83 and
8.42. For 2b-d , the 1H NMR spectra are the same for samples
generated using 1/1 and 2/1 ratios of 1b-d to [Li(Et2O)2.8][B(C6F5)4].

1886 Organometallics, Vol. 22, No. 9, 2003
Shen and J ordan
Ta ble 2. Su m m a r y of Cr ysta llogr a p h ic Da ta for
Gen er a tion of [(d p p p )P d (Me)(CO)][B(C6F 5)4] (3c) a n d
[(d m p e)P d (Me)(CO)][B(C6F 5)4] (3d ). These species were
quantitatively generated from 2c or 2d , [Li(Et2O)2.4][B(C6F5)4],
and CO and handled using the procedures for 3a , except that
CO (1 atm) was applied for 5 min at -78 °C. 1H, 13C{1H}, and
31P{1H} NMR data agree with literature data.14,19
5b‚CH2Cl2
formula
C72H32BCl3F20N2OPd
fw
1244.60
cryst size (mm)
d(calcd), Mg/m3
cryst syst
space group
a, Å
0.24 × 0.16 × 0.12
1.746
monoclinic
P21/n
14.438(3)
Gen er a tion of [(Me2bip y)P d {C(dO)Me}(CO)][B(C6F 5)4]
(4a ). A valved NMR tube containing a CD2Cl2 solution of 2a
and 1 equiv of [Li(Et2O)2.4][B(C6F5)4] generated as described
above was exposed to CO (1 atm) for 5 min at -78 °C. The
NMR tube was briefly warmed to 23 °C and vigorously shaken.
A slurry of a fine white solid in a yellow supernatant was
obtained. The 1H NMR spectrum established that 4a had
b, Å
21.234(4)
c, Å
16.274(3)
â, deg
109.035(3)
4716(2)
V, Å3
Z
4
1
formed quantitatively. H NMR (CD2Cl2, -70 °C): δ 8.23 (d,
T (K)
100
diffractometer
radiation, λ (Å)
2θ range (deg)
data collected: h; k; l
Bruker SMART APEX
Mo KR, 0.710 73
1.90-25.03
J ) 5, 2H), 7.98 (m, 3H), 7.44 (m, 2H), 2.81 (s, 3H, C(dO)Me),
2.51 (s, 3H, bipy-Me), 2.50 (s, 3H, bipy-Me). 13C{1H} NMR
(CD2Cl2, -70 °C): δ 218.9 (C(O)Me), 172.5 (PdCO), 154.8,
154.0, 153.8, 151.3, 150.0, 149.4, 128.2 (2 C), 123.7, 123.4, 40.9
(C(O)Me), 21.3 (two bipy Me).
-17 to +17; -25 to +24;
-19 to +19
no. of rflns collected
no. of unique rflns
no. of obsd rflns
Rint
40 990
8336
I > 2σ(I), 6932
0.0469
0.684
1.0/0.658
Gen er a tion of [(tBu 2bip y)P d {C(dO)Me}(CO)][B(C6F 5)4]
(4b). This compound was quantitatively generated from 2b,
[Li(Et2O)2.4][B(C6F5)4], and CO and handled using the proce-
µ, mm-1
1
dure for 4a . H NMR (CD2Cl2, -70 °C): δ 8.26 (d, J ) 6, 1H),
max/min transmissn
structure soln
8.10 (s, 1H), 8.09 (s, 1H), 8.04 (d, J ) 6, 1H), 7.60 (m, 2H),
t
t
Patterson methodsa
full-matrix least squares on F2
8336/0/683
SADABS based onredundant
diffractions
1.070
R1 ) 0.0374, wR2 ) 0.1021
R1 ) 0.0448, wR2 ) 0.1053
2.615/-0.745
2.82 (s, 3H, C(O)Me), 1.35 (s, 9H, Bu), 1.33 (s, 9H, Bu). 13C-
{1H} NMR (CD2Cl2, -70 °C): δ 218.6 (C(O)Me), 172.5 (PdCO),
166.6, 165.9, 154.5, 151.7, 150.4, 149.8, 125.0, 124.9, 120.0,
119.8, 40.8 (C(dO)Me), 35.6 (CMe3), 35.5 (CMe3), 29.4 (CMe3),
29.3 (CMe3).
refinement method
no. of data/restraints/params
abs cor
GOF on F2
R indices (I > 2σ(I))b
R indices (all data)b
max diff peak/hole (e/Å3)
Gen er ation of [(dppp)P d{C(dO)Me}(CO)][B(C6F5)4] (4c)
a n d [(d m p e)P d {C(dO)Me}(CO)][B(C6F 5)4] (4d ). These spe-
cies were quantitatively generated from 2c or 2d , [Li(Et2O)2.4]-
[B(C6F5)4], and CO and handled using the procedure for 4a .
1H, 13C{1H}, and 31P{1H} NMR data agree with literature
data.14,19
a
SHELXTL-Version 5.1; Bruker Analytical X-ray Systems,
b
2
Madison, WI. R1 ) ∑||Fo| - |Fc||/∑|Fo| and wR2 ) [∑[w(Fo
-
Fc2)2]/∑[w(Fo2)2]]1/2, where w ) q/[σ2(Fo2) + (aP)2 + bP].
[(Me2b ip y)P d {CH ClCH 2C(dO)Me}][B(C6F 5)4] (5a ). A
Schlenk flask was charged with (Me2bipy)Pd(Me)Cl (500 mg,
1.47 mmol) and [Li(Et2O)2.8][B(C6F5)4] (1.31 g, 1.47 mmol), and
CH2Cl2 (40 mL) was added at -78 °C by vacuum transfer. The
pale yellow slurry was vigorously stirred for 10 min and then
exposed to CO (1 atm) at -78 °C for 30 min to yield a white
slurry in pale yellow solution. The mixture was frozen at -196
°C and evacuated, and VC (1.47 mmol) was added by vacuum
transfer from a calibrated gas bulb. The reaction mixture was
thawed, stirred, and warmed to 23 °C to yield a slurry of a
white solid in a yellow supernatant. The mixture was filtered,
and the filtrate was dried under vacuum to afford a yellow
for 5a . Yield: 1.01 g, 88%, pink solid. The color may be due to
a trace impurity; however, further purification by crystalliza-
1
tion was unsuccessful. IR (toluene): νCO 1641 cm-1. H NMR
(CD2Cl2): δ 7.7-7.3 (m, 20H, Ph), 3.53 (m, 2H, CHClCH2), 3.16
(m, 1H, CHCl), 2.67 (m, 2H, PCH2), 2.46 (m, 2H, PCH2), 2.41
(s, 3H, COMe), 2.05 (br m, 2H, PCH2CH2). 13C{1H} NMR (CD2-
Cl2): δ 234.7 (d, J ) 8, COMe), 133.7 (d, J ) 25), 133.5 (s),
132.7 (d, J ) 11), 132.6 (d, J ) 12), 132.2 (d, J ) 2), 131.6 (d,
J ) 2), 130.1 (s), 129.9 (d, J ) 18), 129.8 (d, J ) 2), 129.5 (s),
129.4 (d, J ) 4), 129.0 (s), 128.9 (s), 128.6(s), 127.1 (s), 126.9
(s), 69.2 (dd, J ) 113, 8, CHCl), 60.9 (d, J ) 5, CHClCH2),
29.2 (s, COMe), 27.4 (dd, J ) 34, 8, PCH2), 25.7 (dd, J ) 25, 2,
PCH2), 18.8 (s, PCH2CH2). 31P{1H} NMR (CD2Cl2): δ 21.7 (d,
J ) 60), -3.3 (d, J ) 60). Anal. Calcd for C55H32BClF20OP2Pd:
C, 50.68; H, 2.47. Found: C, 50.81; H, 2.78.
1
solid (1.43 g, 91%). IR (Nujol): νCO 1623 cm-1. H NMR (CD2-
Cl2): δ 8.49 (d, J ) 6, 1H), 8.39 (d, J ) 6, 1H), 7.94 (s, 1H),
7.93 (s, 1H), 7.48 (d, J ) 6, 2H), 7.45 (d, J ) 6, 2H), 4.34 (d, J
) 6, 1H, CHCl), 3.71 (dd, J ) 20, 6, 1H, CHH), 3.35 (d, J )
20, 1H, CHH), 2.59 (s, 3H), 2.58 (s, 3H), 2.57 (s, 3H). 13C{1H}
NMR (CD2Cl2): δ 237.7 (COMe), 156.4, 154.3, 154.1, 152.7,
151.1, 148.9, 128.8, 128.5, 124.3, 123.5, 61.7 (CH2), 56.0
(CHCl), 28.7 (COMe), 21.9 (bipy-Me), 21.8 (bipy-Me). Anal.
Calcd for C40H18BClF20N2OPd: C, 44.68; H, 1.69; N, 2.60.
Found: C, 44.72; H, 1.68; N, 2.71.
[(d m p e)P d {CH ClCH2C(dO)Me}][B(C6F 5)4] (5d ). This
compound was prepared from 1d using the procedure described
for 5a . Yield: 282 mg, 83%, yellow solid. IR (CH2Cl2) νCO 1642
1
cm-1. H NMR (CD2Cl2): δ 3.98 (m, 1H, CHCl), 3.69 (m, 1H,
CHClCHH), 3.50 (m, 1H, CHClCHH), 2.53 (s, 3H, C(O)Me),
2.08 (m, 2H, PCH2), 1.81 (m, 2H, PCH2CH2), 1.70 (d, J ) 12,
3H, PMe), 1.69 (d, J ) 12, 3H, PMe), 1.66 (d, J ) 10, 3H, PMe),
1.53 (d, J ) 10, 3H, PMe). 13C{1H} NMR (CD2Cl2): δ 234.9 (d,
J ) 10, (C(O)Me), 60.6 (d, J ) 4, CHClCH2), 59.8 (dd, J )
120, 2, CHCl), 30.4 (dd, J ) 38, 19, PCH2), 28.9 (s, C(O)Me),
24.6 (dd, J ) 31, 7, PCH2CH2), 13.9 (d, J ) 35, PMe), 12.6 (d,
J ) 34, PMe), 12.5 (d, J ) 21, PMe), 12.0 (d, J ) 22, PMe).
31P{1H} NMR (CD2Cl2): δ 34.6 (d, J ) 30), 22.3 (d, J ) 30).
Anal. Calcd for C34H22BClF20OP2Pd: C, 39.22; H, 2.13.
Found: C, 38.92; H, 2.19.
[(tBu 2bip y)P d {CHClCH2C(dO)Me}][B(C6F 5)4] (5b). This
compound was prepared from 1b using the procedure for 5a .
1
Yield: 1.31 g, 96%, yellow solid. H NMR (CD2Cl2): δ 8.55 (d,
J ) 6, 1H), 8.46 (d, J ) 6, 1H), 8.08 (m, 2H), 7.66 (dd, J ) 6,
2, 1H), 7.64 (dd, J ) 6, 2, 1H), 4.35 (d, J ) 6, 1H, CHCl), 3.71
(dd, J ) 20, 6, 1H, CHH), 3.37 (d, J ) 20, 1H, CHH), 2.59 (s,
3H), 1.44 (s, 18H). 13C{1H} NMR (CD2Cl2): δ 237.8 (COMe),
166.7, 166.6, 156.9, 153.1, 151.4, 149.1, 125.3, 125.0, 120.5,
119.7, 61.6 (CH2), 56.2 (CHCl), 36.2 (two CMe3), 30.2 (CMe3),
30.1 (CMe3), 28.5 (COMe). Anal. Calcd for C46H30BClF20N2-
OPd: C, 47.65; H, 2.61; N, 2.42. Found: C, 47.76; H, 2.86; N,
2.31.
X-r a y Cr ysta llogr a p h ic An a lysis of 5b‚CH2Cl2. Single
crystals of 5b‚CH2Cl2 were grown from CH2Cl2 at -80 °C.
Crystal, data collection and refinement parameters are col-
lected in Table 2. Integration of intensities and refinement of
[(dppp)P d{CHClCH2C(dO)Me}][B(C6F5)4] (5c). This com-
pound was prepared from 1c using the procedure described

Reaction of Vinyl Chloride with Pd Acyl Complexes
Organometallics, Vol. 22, No. 9, 2003 1887
cell parameters were done using SAINT.37 The space group
was determined on the basis of systematic absences and
intensity statistics. Patterson methods were used to locate all
Pd atoms as well as most Cl atoms. Repeated difference
Fourier maps allowed recognition of all C, O, N, F, and B
atoms. Final refinement was anisotropic for non-hydrogen
atoms and isotropic for H atoms. The CH2Cl2 solvent molecule
is slightly disordered; the anisotropic displacement parameters
for one Cl atom (Cl(3)) and the C atom (C(47)) are slightly
larger than normal (see Supporting Information). No treat-
ment was applied.
Ack n ow led gm en t. We thank Dr. Ian Steele for
assistance with X-ray diffraction analyses and Dr.
Chang-J in Qin for assistance with ESI-MS experiments.
This work was supported by the Edison Polymer In-
novation Corp. and the Department of Energy (Grant
No. DE-FG02-00ER15036).
Su p p or tin g In for m a tion Ava ila ble: Text, figures, and
tables which give ESI-MS spectroscopic data for 2b,d and
crystallographic data for 5a and 5b‚CH2Cl2. This material is
available free of charge via the Internet at http://pubs.acs.org.
(37) All software and sources of scattering factors are contained in
the SHELXTL (5.1) program library (G. Sheldrick, Bruker Analytical
X-ray Systems, Madison, WI).
OM021028H