to remove LiCl. The ether was next removed under vacuum or
the phosphinite was used for further syntheses in ether solution.
MS: 340 (M+), 201 (OPPh2), 183 (PPh2), 155 (menthyl). 31P NMR
(CDCl3): 107.3 ppm.
as an external standard and at 500 MHz methylenediphosphonic
acid was used as an external standard.
FTIR spectra were measured on Nicolet Impact 400 spectrom-
eter.
GC-MS an GC analyses were made on a Hewlett Packard
8452A instrument.
PdCl2[PPh2(O-menthyl)]2, 4. To 0.11 g of PdCl2(cod) in 2 cm3
of CH2Cl2 0.5 cm3 of diethyl ether containing 1 mmol of PPh2(O-
menthyl) was added. The yellow solution was stirred for 15 min
and evaporated to dryness. The residue was washed with hexane
giving a pale yellow precipitate. Yield: 76% Anal. Calc. for
Catalytic reactions
The Heck reactions were carried out in a Schlenk tube with
magnetic stirring. The catalyst (1.41 × 10−5 mol) was weighed
in a small Teflon vessel, [nBu4N]Br (2.3 × 10−3 mol) and NaHCO3
(4.4 × 10−3 mol) were introduced to the Schlenk tube which was
next evacuated and filled with N2. Reagents: 1.89 × 10−3 mol
of butyl acrylate, 4.36 × 10−3 mol of bromobenzene and 7.15 ×
10−4 mol of mesitylene (internal standard) were introduced under
an N2 atmosphere. Next the Schlenk tube was sealed with a
1
PdC44H58O2P2Cl2: C, 61.6; H, 3.38. Found: C, 61.1; H, 3.5%. H
NMR (CDCl3): 0.4 d (J(H–H) 7 Hz), 0.81 d (J(H–H) 7 Hz), 0.87
d (J(H–H) 7 Hz), 1.5 m, 2.53 m, 3.27 m, 5.26 m, 7.06 m, 7.92
m; 31P NMR (CDCl3): 100.2 ppm; UV-Vis (CHCl3): 264, 340 nm;
IR/KBr (cm−1): 2900vs, 1420s, 1100s, 1000vs, 680s, 530s, 500s;
IR/Nujol (cm−1): 316.
[l-ClPd(PPh2OH)(PPh2O)]2, 5. To 0.066 g PdCl2(cod) 0.2 cm3
of PPh2Cl in 2 cm3 of benzene was added and the resultant mixture
was stirred for 2 h. Next H2O (0.05 cm3) was added and after 5 min
2 cm3 of EtOH. Stirring was continued for 1 h and the resultant
whiteprecipitate was filtered off, washed with ethylether anddried.
Yield: 0.17 g. Anal. Calc. For Pd2Cl2C48H42O4P4: C, 52.89; H,
3.70 Found: C, 52.64; H, 3.50%. IR/KBr (cm−1): 1480vs, 1100vs,
1015m, 730m, 710m, 680vs, 500m; IR/Nujol (cm−1): 333.3, 275.0
◦
rubber tap and introduced into an oil bath pre-heated to 140 C
for the reaction time 4 h. After that time the Schlenk tube was
cooled and any organic products were separated by extraction
with diethyl ether (3 times with 10 cm3) and GC-FID analyzed
(Hewlett Packard 8452A). The products were identified by GC-
1
MS (Hewlett Packard 8452A). H NMR spectroscopy was used
as a complementary method of product identification as well
as determination of the reaction yield. Samples for 1H NMR
measurements were prepared in CDCl3 after vacuum removal of
diethyl ether from the extract.
For recycling experiments the solid residue obtained after the
extraction of the liquid products was dried in vacuum, next the
liquid reagents and NaHCO3 in the amounts given above were
added under a N2 atmosphere.
The methoxycarbonylation reactions were carried out in a
130 cm3 thermostated steel autoclave with magnetic stirring.
Reagents: PhI (9.4 × 10−3 mol), NEt3 (2.15 × 10−2 mol), methanol
(2.5 × 10−2 mol), mesitylene-internal standard (4.6 × 10−3 mol),
and palladium catalyst (1.41 × 10−5 mol), were introduced into
the autoclave under an N2 atmosphere. Next, the N2 atmosphere
was replaced by CO (5 atm). The reaction was carried out at 90 ◦C
for 3 h. Afterwards, the autoclave was cooled and any organic
products were separated by extraction with diethyl ether (3 times
with 3 cm3) and GC-FID analyzed (Hewlett Packard 8452A) or
condensed under vacuum to remove diethyl ether and analyzed
using 1H NMR spectroscopy (Bruker 500 MHz) after CDCl3
addition.
1
(m(Pd–Cl)); UV-Vis (CHCl3): 350 nm; H NMR(CDCl3): 7.15m
(Ph), 10.0 br (OH) ppm. 31P NMR(CDCl3): 76.6 ppm (at 500 MHz
with methylenediphosphonic acid as external standard), 78.0 ppm
(at 300 MHz with 85% H3PO4 as external standard).
[l-ClPd(P(OPh)2OH)(P(OPh)2O)]2, 6. To 0.07
g
of
PdCl2(cod) in 1 cm3 of benzene 0.12 cm3 of P(OH)(OPh)2
was added and a white precipitate formed immediately. The
mixture was stirred for 1 h and after that time the product was
filtered off, washed with diethyl ether and dried in vacuo. Yield:
0.09 g. Anal. Calc. For Pd2Cl2C48H42O12P4: C, 47.4; H, 3.3 Found:
C, 47.1; H, 3.19%. IR/KBr (cm−1): 1600s, 1480vs, 1200vs, 900vs,
750m, 700m, 500m; IR/Nujol (cm−1): 381.7, 338.0 (m(Pd–Cl)); 1H
NMR(CDCl3): 7.15m (Ph), 10.0 br (OH) ppm; 31P NMR(CDCl3:
65.5 ppm.
[Pd[P(O)(OPh)2]2]n, 7. To 0.22 g of Pd(OAc)2 in 2 cm3 of
benzene 0.4 cm3 of P(OH)(OPh)2 was added and the resultant
mixture was stirred at ambient temperature. After a few minutes
the solution became homogeneous and colourless, then a white
precipitate started to form. Stirring was continued for 2 h and
next diethyl ether was added to complete precipitation of product
which was filtered off and dried in vacuo. Yield: 0.38 g. IR/KBr
(cm−1): 1600s, 1490vs, 1200vs, 1100vs, 920vs, 760m, 700m, 500m;
IR/Nujol(cm−1): 3400 (m(OH)); 31P NMR (CDCl3, measured in
situ): 86.8 ppm.
X-Ray crystallography
A suitable crystal was glued on top of a glass fiber and transferred
into the cold nitrogen stream on a Kuma KM4CCD j-axis
diffractometer (graphite-monochromated Mo-Ka radiation, k =
[Pd[P(O)Ph2)]2]n, 8. To a solution of complex 5 (0.05 g) in 1 cm3
of CHCl3 triethylamine (0.05 cm3) was added dropwise. After a few
minutes a pale yellow precipitate was formed, which was filtered
off, washed with CHCl3 and dried under vacuum. Yield; 0.038 g.
IR/KBr (cm−1): 1437s, 1108s, 1022vs, 742m, 713m, 690s, 535s.
˚
0.71073 A). The crystal was positioned at 65 mm from the CCD
camera. 612 frames were measured at 0.75◦ intervals with a
counting time of 20 s. Accurate cell parameters were determined
and refined by least-squares fit of 4800 of the strongest reflections.
Data were corrected for Lorentz and polarization effects. Analyt-
ical absorption correction was also applied. Data reduction and
analysis were carried out with the Oxford Diffraction (Poland)
programs. The structure was solved by the heavy method (program
SHELXS9731) and refined by the full-matrix least-squares method
Measurements
1H, and 31P NMR spectra were recorded on Bruker 300 and Bruker
500 spectrometers. For 31P NMR at 300 MHz 85% H3PO4 was used
This journal is
The Royal Society of Chemistry 2006
Dalton Trans., 2006, 213–220 | 2 1 9
©