4676 J. Am. Chem. Soc., Vol. 119, No. 20, 1997
Kuniyasu et al.
5 (120 mg, 0.2 mmol), 2 (109 mg, 0.93 mmol), and benzene (1.0 mL)
under an argon atmosphere. After the solution was refluxed with
stirring for 36 h, the reaction mixture was separated by PTLC and then
Confirmation of 12. To retard the dimerization of 12 to 13, the
reaction of 1 with Pd(PPh3)4 was carried out in the presence of an excess
amount of PPh3. After 1 (2.5 mg, 0.01 mmol), Pd(PPh3)4 (11.6 mg,
0.01 mmol), PPh3 (26.2 mg, 0.1 mmol), and benzene-d6 (0.6 mL) were
added into a dry NMR tube, 1H and 31P NMR spectra were taken. The
peaks of 12 close to the corresponding platinum complex 18 were
confirmed in 18% yield (one isomer; stereochemistry undetermined).
12: 1H NMR (400 MHz, C6D6) δ 2.08 (s, 6 Η), 6.58 (d, J ) 8.1 Hz,
4 H), 6.88 (d, J ) 8.1 Hz, 4 H), 7.80-7.84 (m, 12 H) (the other peaks
1
HPLC. From 1:1 to 1:9 adducts were isolated and assigned by H
NMR and mass spectra; however, the products which have larger mass
number were not able to be assigned. The products and their yields
(based on 5 and 2) were as follows: 1:1 adduct 3, 1.2 mg (1.6%); 1:2
adduct 4, 5 mg, (5%); 1:3 adduct 5 recovered, 25 mg (21%); 1:4 adduct
6, 25 mg (18% (4%)); 1:5 adduct 7, 8 mg (8% (4%)); 1:6 adduct 8, 9
mg (5% (3%)); 1:7 adduct 9, 12 mg (6% (5%)); 1:8 adduct 10, 11 mg
(5% (5%)); 1:9 adduct 11, 22 mg (8% (11%)), and undetermined
compounds, 61 mg combined. The mass spectra of these undetermined
products showed 1404, 1527, and 1644 as fragments which correspond
to (CdNAr)12, (ArS)(CdNAr)12, and (ArS)(CdNAr)13 fragments,
indicating more than 10 isocyanides were incorporated into the
molecules.
were not assigned because of overlapping with the peaks of PPh3); 31
P
NMR (149 MHz, C6D6) δ -118.05.
Preparation of Authentic 13. In a two-necked dry 50 mL flask
equipped with stirring bar were added Pd(PPh3)4 (1.3 g, 1.1 mmol), 1
(740 mg, 3.0 mmol), and benzene (25 mL). After the mixture was
stirred at room temperature for 21 h, the red solid was emptied by
filtration. Then the solid was recrystallized from CH2Cl2 and hexane
to give a dark red needle-shaped crystal.
1
7: mp 73-74 °C (an yellow solid); H NMR (270 MHz, C6D6 at
1
13: mp 166-167 °C (a dark red solid); H NMR (270 MHz, CD2-
rt) of a major isomer δ 1.78 (s, 6 H), 1.99 (s, 3 H), 2.05-2.13 (9 H),
2.18 (s, 3 H), 6.56 (d, J ) 7.8 Hz, 4 H), 6.67 (d, J ) 8.3 Hz, 2 H),
6.81-7.28 (m, 16 H), 7.37-7.41 (6 H); IR (KBr) 3023, 2921, 1630,
1611, 1501, 1212, 1198, 1018, 880, 862, 806 cm-1; mass spectrum
(EI) m/e 831 (M+, 5).
8: mp 222-223 °C (an yellow solid); 1H NMR (270 MHz, C6D6 at
rt) of a major isomer δ 1.71 (s, 3 H), 1.94 (s, 3 H), 2.05 (s, 3 H), 2.09
(s, 3 H), 2.14 (s, 3 H), 2.14 (s, 3 H), 2.15 (s, 3 H), 2.18 (s, 3 H), 6.52
(d, J ) 8.3 Hz, 4 H), 6.65 (d, J ) 8.3 Hz, 2 H), 6.95-7.18 (m, 20 H),
7.29 (d, J ) 8.3 Hz, 2 H), 7.46 (d, J ) 8.3 Hz, 4 H); mass spectrum
(EI) m/e 948 (M+, 3).
9: mp 215-216 °C (an yellow solid); 1H NMR (270 MHz, C6D6 at
rt) of a major isomer δ 1.70 (s, 3 H), 1.85 (s, 3 H), 1.86 (s, 3 H), 2.03
(s, 3 H), 2.10 (s, 3 H), 2.15 (s, 3 H), 2.19 (s, 3 H), 2.02 (s, 3 H), 2.23
(s, 3 H), 6.26 (d, J ) 8.3 Hz, 2 H), 6.48-6.55 (m, 4 H), 6.65-6.75
(m, 6 H), 6.82-7.38 (m, 18 H), 7.43-7.54 (m, 6 H); IR (KBr) 3024,
2920, 1634, 1593, 1558, 1500, 1446, 1212, 1198, 1018, 878, 807, 706,
518 cm-1; mass spectrum (EI) m/e 1065 (M+, 4). Anal. Calcd for
C70H63N7S2: C, 78.84 H, 5.95; N, 9.19; S, 6.01. Found: C, 78.09; H,
6.09; N, 8.85; S, 5.81.
10: mp 232-233 °C (an yellow needle); 1H NMR (270 MHz, C6D6
at 60 °C) of a mixture of isomers δ 1.60, 1.79, 1.86, 1.89, 1.94, 2.02,
2.04, 2.08, 2.14, 2.19, 2.23, 2.25, 6.21 (d, J ) 8.1 Hz), 6.28 (d, J )
8.1 Hz), 6.50-7.50 (m); 13C NMR (68 MHz, CDCl3 at 45 °C) δ 20.67-
21.11 (m), 118.11-121.16; 127.22-129.45 (m); IR (KBr) 3023, 2920,
1631, 1620, 1609, 1597, 1501, 1199, 1037, 1018, 889, 802 cm-1; mass
spectrum (EI) m/e 1182 (M+, 4). Anal. Calcd for C78H70N8S2: C,
79.15; H, 5.96; N, 9.47. Found: C, 78.96; H, 5.94; N, 9.34.
Cl2) of a major isomer δ 2.11 (s, 6 H), 2.20 (s, 6 H), 6.52 (d, J ) 7.8
Hz, 4 H), 6.61 (d, J ) 7.8 Hz, 4 H), 7.07 (d, J ) 7.8 Hz, 4 H), 7.09
(d, J ) 7.8 Hz, 4 H), 7.24-7.29 (m, 12 H), 7.36-7.43 (m, 18 H); 31
P
NMR (160 MHz, CD2Cl2) of major-isomer δ -113.66 and minor-
isomer δ -114.82; IR (KBr) 3056, 3006, 1482, 1433, 1096, 801, 748,
692, 526 cm-1. Anal. Calcd for C64H58P2Pd2S4: C, 62.49; H, 4.75.
Found: C, 61.95; H, 5.08.
Preparation of Authentic 14. Into a Pyrex NMR tube were added
13 (11.5 mg, 0.0093 mmol), 1 (2.2 mg, 0.019 mmol) and benzene-d6
(0.7 mL). After the formation of 14 was confirmed at room temperature
for 1 h, the reaction mixture was concentrated in Vacuo and 0.1 mL of
CH2Cl2 was added. When 0.5 mL of hexane was added into the reaction
mixture, a brown solid precipitated. The solution was removed by
syringe, and the solid was washed by 0.5 mL × 2 of hexane to give
8.0 mg of 14 (58%).
14: mp 115-117 °C (a brown solid);1H NMR (270 MHz, C6D6) of
trans-isomer δ 1.69 (s, 3 H), 1.99 (s, 6 H), 6.07 (d, J ) 7.8 Hz, 2 H),
6.35 (d, J ) 7.8 Hz, 2 H), 6.72 (d, J ) 7.8 Hz, 4 H). 7.00-7.10 (m,
9 H), 7.87 (d, J ) 7.8 Hz, 4 H), 7.90-8.05 (m, 6 H) and cis-isomer δ
1.72 (s, 3 H), 1.95 (s, 3 H), 2.07 (s, 3 H), 5.91 (d, J ) 7.8 Hz, 2 H),
6.48 (d, J ) 7.8 Hz, 2 H) (the other peaks overlapped with the peaks
of trans-isomer); 31P NMR (160 MHz, C6D6) of trans-isomer δ -112.09
and cis-isomer δ -113.51; IR (KBr) (a mixture of stereoisomers) 3056,
2915, 2196, 1504, 1484, 1434, 1096, 1086, 809, 743, 705, 692, 528,
504 cm-1. Anal. Calcd for C40H36NPPdS2: C, 65.60; H, 4.95; N, 1.91;
S, 8.76. Found: C, 65.82; H, 5.27; N, 1.79; S, 8.91.
The Reaction of 3 with Pd(PPh3)4 (Eq 5). Into a dry Pyrex NMR
tube were added 3 (6.8 mg, 0.019 mmol), Pd(PPh3)4 (21.6 mg, 0.019
mmol), and benzene-d6 (0.7 mL). Then the tube was purged with Ar
and sealed under reduced pressure. By leaving the sample at room
temperature, 14 was formed in 70% yield (cis/trans ) 10/90) after 5
h and in 87% yield (3, trace) after 20 h.
1
11: mp 105-106 °C (an orange solid); H NMR (270 MHz, C6D6
at rt) of a major isomer δ 1.73 (s, 3 H), 1.83 (s, 6 H), 1.95 (s, 6 H),
2.01 (s, 3 H), 2.18 (br, 15 H), 6.60-7.44 (br, 44 H); IR (KBr) 3023,
2921, 1636, 1606, 1449, 1211, 1197, 862, 807 cm-1; mass spectrum
(EI) m/e 1299 (M+, 2).
The Reaction of 4 or 5 with Pd(PPh3)4 (Eq 6). In a dry Pyrex
NMR tube were added 4 (24.4 mg, 0.05 mmol), Pd(PPh3)4 (58 mg,
0.05 mmol), and benzene-d6 (0.7 mL). Then the tube was purged with
Ar, sealed under reduced pressure, and heated at 50 °C. However,
most of the starting 4 remained unreacted, although partial decomposi-
tion of 4 was observed after 12 h. The reaction of 5 with Pd(PPh3)4
also gave only a small amount of undetermined complex products.
The Reaction of 3 with Pd2(dba)3/dppe (Ref 17). Into a dry Pyrex
NMR tube were added 3 (7.3 mg, 0.02 mmol), Pd2(dba)3‚CHCl3 (10.4
mg, 0.01 mmol), dppe (8.0 mg, 0.02 mmol), and benzene-d6 (0.7 mL).
Then the tube was purged with Ar and sealed under reduced pressure.
By leaving the sample at room temperature for 5 h, the formation of
Pd(SAr)2(dppe) was confirmed in 45% yield.
Stoichiometric Reactions of Pd(PPh3)4 with 1 and Then 2 in NMR
Tubes (Scheme 2). In two dry Pyrex NMR tubes were added Pd-
(PPh3)4 (21.9 mg, 0.019 mmol), 1 (4.7 mg, 0.019 mmol), and benzene-
d6 (0.7 mL), respectively. The samples were degassed under reduced
pressure and purged with Ar several times. After 1,4-dioxane (2.9 mg,
1
0.033 mmol) was added as an internal standard, the H NMR and 31P
NMR spectra were taken (<5 min). The formation of Pd(SAr)2(PPh3)2
(12) (stereochemisty unassigned) and [Pd(SAr)2(PPh3)]2 (13) (stere-
ochemisty unassigned) was confirmed in 34% and 44% yields,
respectively. After 1.5 h the peaks of 12 disappeared and a red solid
started to precipitate. After 12 h, the signal of 1 disappeared and only
the signals of free PPh3 and 13 were confirmed by the measurement of
1H NMR. Then, 2 (2.2 mg, 0.019 mmol) was added into the NMR
tubes. After 3 h at room temperature, the red solid 13 disappeared
and the formation of Pd(SAr)2(CNAr)(PPh3) 14 was confirmed in 85%
yield (cis/trans ) 10/90). Then a sample was heated at 80 °C and
monitored by 1H NMR. Gradual decomposition into complex products
was confirmed, but 3 was not detected at all. On the other hand, when
another 1 equiv of 1 (4.7 mg, 0.019 mmol) was added into the other
sample and the mixture was heated at 80 °C, a gradual formation of 3
was confirmed in 61% and 73% yields (based on 2) accompanied with
a formation of red precipitate 13 after 4 and 15 h, respectively.
Pd(SAr)2(dppe): 1H NMR (270 MHz, C6D6) δ 1.83 (d, JP-H
)
20.5 Hz, 4 H), 2.01 (s, 6 H), 6.63 (d, J ) 8.4 Hz, 4 H), 7.04-7.09 (m,
4 H), 7.25-7.31 (m, 8 H), 7.63 (d, J ) 8.4 Hz, 4 H), 7.68-7.76 (m,
8 H).
Oxidative Addition of 1 to Pd(PPh3)4 in the Presence of 2 (Ref
18). In a dry Pyrex NMR tube were added Pd(PPh3)4 (23.1 mg, 0.020
mmol), 2 (7.6 mg, 0.065 mmol), and benzene-d6 (0.7 mL). After the
sample was left at room temperature for 10 min, 1 (4.9 mg, 0.020 mmol)
was added. The 1H NMR spectrum after 2 h at room temperature
showed the formation of 14 in 73% yield. The signals of 14 and 2