Reactions of the Stable (Phosphanyl)(silyl)carbenes
J. Am. Chem. Soc., Vol. 122, No. 18, 2000 4469
4′a: A pentane solution (3 mL) of the diazo compound 5a11a (0.1 g,
0.37 mmol) and nonafluoro-1-hexen (193 µL, 1.11 mmol) was heated
at 40 °C. The reaction was monitored by 31P NMR spectroscopy, and
the cyclopropane 4′a was obtained after 2 h in near-quantitative yield
(according to the NMR spectroscopy). 31P{1H} NMR (CDCl3) δ 50.6;
19F{1H} NMR (CDCl3) δ -50.1 and -46.2 (m, CF3-CF2-CF2-),
95%). Mp 163-164 °C; 31P{1H} NMR (CDCl3) δ 85.9 and 93.1 (2
1
rotamers 60/40); H NMR (CDCl3) major rotamer δ 0.25 (s, 9 H,
3
3
SiCH3), 1.07-1.54 (m, 24 H, CHCH3), 1.71 (dd, JHH ) 7.3 Hz, JPH
) 19.4 Hz, 1 H, CHD), 2.50 (dd, 3JHH ) 7.3 Hz, 3JPH ) 18.6 Hz, 1 H,
CH), 3.85 (m, 4 H, CHCH3), 7.19-7.80 (m, 5 H, Harom), minor rotamer
2.42 (dd, 3JHH ) 8.0 Hz, 3JPH ) 22.4 Hz, 1 H, CHD), 2.68 (dd, 3JHH
7.9 Hz, JPH ) 16.8 Hz, 1 H, CH).
)
3
3
-35.4 (m, CF2-CH), -5.0 (t, JFF ) 8.7 Hz, CF3).
6a: 31P{1H} NMR (C6D6) δ 76.6 and +61.0 ppm (2 rotamers, 90/
10 ratio).
Reaction of the Diazo 13a in the Presence of (Z)-2-Deuteriosty-
rene. A pentane solution (3 mL) of phosphanyl(silyl) diazomethane
(13a, 0.10 g, 0.30 mmol) and 3 equiv of (Z)-2-deuteriostyrene (0.09 g,
0.90 mmol) was irradiated at 300 nm for 18 h. According to 31P NMR
spectroscopy the reaction was quantitative (δ 73.5). Treatment of the
solution mixture with an excess of elemental sulfur gave the thioxo-
phosphoranyl derivatives 10a and 12a in a 90/10 ratio (according to
1H NMR spectroscopy).
7a: (pentane/ether, 98/2, RF ) 0.6). (0.12 g; 90%). Mp 163-164
°C; 31P{1H} NMR (C6D6) δ 85.9 and 93.2 (2 rotamers, 60/40); 1H NMR
3
(C6D6) major rotamer δ 0.33 (s, 9 H, SiCH3), 0.50 (d, 6 H, JHH
)
3
7.0 Hz, CHCH3), 1.13 (d, 6 H, JHH ) 6.8 Hz, CHCH3), 1.29-1.50
2
3
3
(m, 12 H, CHCH3), 1.73 (ddd, JHH ) 4.2 Hz, JHH ) 7.3 Hz, JPH
)
3
3
19.6 Hz, 1 H, CH2), 2.53 (td, JHH ) 7.8 Hz, JPH ) 17.6 Hz, 1 H,
CH), 3.54-4.11 (m, 4 H, CHCH3), 7.17-7.61 (m, 5 H, Harom), one of
the CH2 protons was not observed, minor rotamer δ 0.30 (s, 9 H,
SiCH3), 1.27-1.51 (m, 24 H, CHCH3), 2.43 (ddd, 2JHH ) 3.9 Hz, 3JHH
1
14a: Yellow oil. 31P{1H} NMR (C7D8) δ 94.0; H NMR (C7D8) δ
4
3
0.65 (d, JPH ) 1.0 Hz, 9 H, SiCH3), 1.45 (d, 6 H, JHH ) 6.8 Hz,
3
3
CHCH3), 1.49 (d, 6 H, JHH ) 6.8 Hz, CHCH3), 1.55 (d, 6 H, JHH
)
) 8.6 Hz, 3JPH ) 20.6 Hz, 1 H, CH2), 2.69 (td, 3JHH ) 8.0 Hz, 3JPH
)
3
6.8 Hz, CHCH3), 1.71 (d, 6 H, JHH ) 6.8 Hz, CHCH3), 2.81 (s, 3 H,
CH3N), 2.84 (s, 3 H, CH3N), 3.00 (dd, 3JHH ) 6.4 Hz, 3JPH ) 4.8 Hz,
17.2 Hz, 1 H, CH), 3.54-4.11 (m, 4 H, CHCH3), 7.17-7.61 (m, 5 H,
arom), one of the CH2 protons was not observed; 13C{1H} NMR (C6D6)-
3
3
H
1 H, CHring), 3.50 (dd, JHH ) 6.4 Hz, JPH ) 11.4 Hz, 1 H, CHring),
3.59 (s, 3 H, CH3O), 3.80 (sept d, 3JHH ) 6.8 Hz, 3JPH ) 9.0 Hz, 4 H,
CHCH3); 13C{1H} NMR (C7D8) δ 1.9 (d, 3JPC ) 8.8 Hz, SiCH3), 24.8
(d, 3JPC ) 4.9 Hz, CHCH3), 24.9 (d, 3JPC ) 3.5 Hz, CHCH3), 34.6 (d,
2JPC ) 3.4 Hz, CHring), 35.8 (s, CH3N), 35.9 (d, 2JPC ) 7.2 Hz, CHring),
36.7 (d, 1JPC ) 100.0 Hz, PCSi), 37.5 (s, CH3N), 51.6 (s, CH3O), 52.4
(d, 2JPC ) 15.9 Hz, CHN), 170.8 (d, 3JPC ) 6.5 Hz, CO), 174.1 (d, 3JPC
) 5.2 Hz, CO).
2
major rotamer δ 0.6 (s, SiCH3), 15.1 (d, JPC ) 5.1 Hz, CH2), 21.0
1
3
(d, JPC ) 91.6 Hz, PC), 23.7 (d, JPC ) 6.9 Hz, CHCH3), 24.0 (s,
3
CHCH3), 25.5 (s, CHCH3), 26.6 (d, JPC ) 1.2 Hz, CHCH3), 29.6 (d,
2
4
2JPC ) 5.9 Hz, CH), 48.2 (d, JPC ) 6.0 Hz, CHN), 126.9 (d, JPC
)
17.4 Hz, Co), 128.2 (s, Cp), 130.8 (d, 4JPC ) 8.5 Hz, Cm), 137.5 (s, Ci).
Anal. Calcd for C24H45N2SiPS: C, 63.67; H, 10.02; N, 6.19. Found:
C, 64.01; H, 10.15; N, 5.98.
6b: Yellow crystals from a pentane solution at -20 °C (0.16 g,
95%). Mp 210-211 °C; 31P{1H} NMR (CDCl3) δ 76.4 and +67.4 ppm
(2 rotamers, 95/5 ratio). Anal. Calcd for C36H61N2SiP: C, 70.43; H,
10.58; N, 4.82. Found: C, 70.23; H, 10.45, N, 4.65.
7b (hexane/ether, 95/5, RF ) 0.8): Pale yellow crystals were obtained
by slow evaporation of a pentane solution (0.16 g; 90%). Mp 196-
197 °C; 31P{1H} NMR (CDCl3) δ 84.4. Anal. Calcd for C36H61N2-
SiPS: C, 70.54; H, 10.03; N, 4.57. Found: C, 70.14; H, 9.83, N, 4.71.
15a: White crystals obtained by slow evaporation of a ether solution
(0.06 g; 45%). Mp 191-192 °C dec; 31P{1H} NMR (C7D8) δ 90.8; 1H
NMR (C7D8) δ 0.76 (s, 9 H, SiCH3), 1.20-2.17 (m, 24 H, CHCH3),
3
3
2.90 (dd, JHH ) 5.4 Hz, JPH ) 18.8 Hz, 1 H, CHring), 2.89 (s, 3 H,
3
CH3N), 3.07 (s, 3 H, CH3N), 3.34 (s, 3 H, CH3O), 3.35 (dd, JHH
)
5.4 Hz, 3JPH ) 16.4 Hz, 1 H, CHring), 4.23, 4.44, 4.50, and 4.63 (m, 4
H, CHCH3); 13C{1H} NMR (C7D8) δ 4.3 (s, SiCH3), 23.0 (s, CHCH3),
3
23.8 (s, CHCH3), 25.6 (s, CHCH3), 25.8 (s, CHCH3), 25.9 (d, JPC
)
8a and 8′a: 31P{1H} NMR (CD2Cl2, 293 K) δ 89.7 very large. By
cooling the sample, two rotamers were observed for each compound,
31P{1H} NMR (CD2Cl2, 223 K) δ 96.5 and 88.0 (major isomer 8a),
87.8 and 87.0 (minor isomer 8′a). At 193 K, only one rotamer was
detected for each isomer,31P{1H} NMR (CD2Cl2, 193 K) δ 88.0 (8a),-
and 87.8 (8′a) (90/10 ratio). The major isomer 8a precipitated from a
pentane solution at -50 °C as colorless crystals (0.04 g; 40%). Mp
2
2
4.2 Hz, CHCH3), 29.2 (d, JPC ) 3.1 Hz, CHring), 33.6 (d, JPC ) 2.7
1
Hz, CHring), 34.9 (d, JPC ) 79.7 Hz, PCSi), 35.6 (s, CH3N), 39.3 (s,
CH3N), 53.1 (s, CH3O), 47.3 (s, CHN), 47.8 (d, 2JPC ) 7.4 Hz, CHN),
50.1 (s, CHN), 51.7 (d, 2JPC ) 8.2 Hz, CHN), 166.2 (d, 3JPC ) 6.6 Hz,
CO), 171.9 (d, 3JPC ) 4.4 Hz, CO). Anal. Calcd for C23H48N3O3SiPS:
C, 54.62; H, 9.57; N, 8.31. Found: C, 54.83; H, 9.70; N, 8.41.
Competition Experiments (p-X-C6H4-CHdCH2 vs C6H4-CHd
CH2) Using Carbene 1b. In a typical experiment, 1 equiv of styrene
and 1 equvi of para-substituted-styrene (X ) CH3O, F, CF3) was added
at room temperature to a pentane solution (3 mL) of phosphanyl(silyl)-
carbene 1b. When the reaction had reached completion (1-3 h), volatile
components were removed in vacuo, and the ratios of the resulting
cyclopropanes were determined by 1H NMR spectroscopy without any
further purification. The phosphanylcyclopropanes resulting from the
reaction of 1b with the different para-substituted-styrenes were
independently prepared. X ) CH3O: 31P{1H} NMR (CDCl3) δ 76.7
and +68.5 (2 rotamers, 90/10 ratio); 1H NMR (CDCl3) δ 0.11 (s, 9 H,
SiCH3), 0.53-1.64 (m, 41 H, CH2 and CHring), 2.51-2.89 (m, 6 H,
CHN and CHring), 3.64 (s, 3 H, CH3O), 6.54-7.17 (m, 5 H, CHarom). X
) F: 31P{1H} NMR (CDCl3) δ 76.2 and +67.7 (2 rotamers, 90/10
ratio); 1H NMR (CDCl3) δ 0.12 (s, 9 H, SiCH3), 0.81-1.63 (m, 41 H,
CH2 and CHring), 2.52-3.04 (m, 6 H, CHN and CHring), 6.73-7.15
(m, 5 H, CHarom). X ) CF3: 31P{1H} NMR (CDCl3) δ 76.3 and +67.9
1
147-148 °C; H NMR (CD2Cl2, 193 K) δ 0.23 (s, 9 H, SiCH3), 1.22
(d, 12 H, 3JHH ) 6.7 Hz, CHCH3), 1.23 (d, 6 H, 3JHH ) 6.7 Hz, CHCH3),
3
1.29 (d, 3 H, JHH ) 7.2 Hz, OCH2CH3), 1.43 (s, 9H, tBu), 2.56 (tlike
,
3JHH ) 3JPH ) 6.1 Hz, 1 H, CHring), 2.73 (dd, 1 H, 3JHH ) 6.0 Hz, 3JPH
) 12.2 Hz, CHring), 3.50 (m, 4 H, CHCH3), 4.00 (dq, 1 H, 3JHH ) 7.2
Hz, 2JHH ) 10.8 Hz, OCH2CH3), 4.22 (dq, 1 H, 3JHH ) 7.2 Hz, 2JHH
10.8 Hz, OCH2CH3); 13C{1H} NMR (CD2Cl2, 193 K) δ 0.9 (d, 3JPC
)
)
9.6 Hz, SiCH3), 14.5 (s, OCH2CH3), 24.5 (d, 3JPC ) 17.5 Hz, CHCH3),
26.9 (d, 3JPC ) 15.3 Hz, CHCH3), 28.1 (s, OC(CH3)3), 34.8 (d, 2JPC
)
2
1
2.3 Hz, CHring), 35.7 (d, JPC ) 9.0 Hz, CHring), 38.1 (d, JPC ) 91.8
2
2
Hz, PCSi), 45.1 (d, JPC ) 37.9 Hz, CHN), 51.1 (d, JPC ) 10.0 Hz,
3
CHN), 61.4 (s, OCH2CH3), 81.0 (s, OC(CH3)3), 172.8 (d, JPC ) 5.4
3
Hz, CO), 174.8 (d, JPC ) 8.0 Hz, CO). Anal. Calcd for C26H53N2O4-
PSi: C, 60.43; H, 10.34; N, 5.42; Found: C, 60.22; H, 10.28; N, 5.36.
9a: 31P{1H} NMR (C6D6) δ 73.5.
10a (pentane/ether, 98/2, RF ) 0.6): Colorless crystals of 10a were
obtained by slow evaporation of a dichloromethane solution (0.13 g;
95%). Mp 161-162 °C; 31P{1H} NMR (C7D8) δ 85.9 and 93.0 (2
rotamers, 60/40); 1H NMR (C7D8) major rotamer δ 0.51 (s, 9 H,
1
(2 rotamers, 90/10ratio); H NMR (CDCl3) δ 0.14 (s, 9 H, SiCH3),
0.43-1.99 (m, 41 H, CH2 and CHring), 2.56-2.96 (m, 6 H, CHN and
CHring), 7.24-7.39 (m, 5 H, CHarom).
SiCH3), 1.11 (d, 12 H, 3JHH ) 7.0 Hz, CHCH3), 1.13 (d, 12 H, 3JHH
)
X-ray Crystallographic Studies of Compounds 2a, 6b, 7a, 7b,
8a, and 15a. Crystal data for all structures are presented in Table 1.
Data for 6b, 7a, 7b, and 15a were collected at low temperatures on a
Stoe-IPDS diffractometer and data for 2a and 8a were collected at room
temperature on a Bruker-CCD with Mo KR (λ ) 0.71073 Å). The
structures were solved by direct methods by means of SHELXS-9723
7.0 Hz, CHCH3), 2.52 (dd, 3JHH ) 7.8 Hz, 3JPH ) 17.6 Hz, 1 H, CH),
the proton of CDH was not observed, 4.32 (m, 4 H, CHCH3), 7.22-
3
3
7.71 (m, 5 H, Harom), minor rotamer δ 2.69 (dd, JHH ) 8.5 Hz, JPH
) 16.8 Hz, 1 H, CH), the proton of CDH was not observed.
11a: 31P{1H} NMR (C6D6) δ 73.5.
12a (pentane/ether, 98/2, RF ) 0.5): Colorless crystals of 12a were
obtained by slow evaporation of a dichloromethane solution (0.13 g;
(23) Sheldrick, G. M. Acta Crystallogr. Sect. A 1990, 46, 467.