415
General procedure for the hydrogenation experiments
The phosphaalkene complex (2 retool) was added to a solution of 0.2 mmol of the
rhodium complex Rh(COD)2PF6 (or 0.1 mmol of [RhC1 (COD)]2) and 0.2 mmol of
diphos in CH2C12 or acetone (10 ml). The mixture was introduced into the
hydrogenation flask under inert atmosphere. The flask was evacuated and then
filled with hydrogen up to a total pressure of 8 bars. The mixture was stirred at
room temperature and the extent of hydrogenation was determined by 31p NMR
spectroscopy. The final product was purified by column chromatography with
hexane as eluent.
Hydrogenation of complex 1: reactions 2 and 3
A mixture of 2 and 3 was obtained. The ratio 2 : 3 was established by 31p NMR
spectroscopy. Complex 2 was described previously [5b]. Complex 3 was obtained in
71% yield after 25 h of reaction in acetone with Rh(diphos)C1 as catalyst: colorless
oil; 31p NMR (CDC13): /~ -0.95 (1j(31p-183W) -- 225 Hz). 1H NMR (CDCI3): 8
1.07 (dd, ~/(H-H)= 6.8, ~r(H-p)= 17.3 Hz, 3H, CH3); 1.13 (dd, ~r(n-H) --- 6.9,
3j(H-P) = 18.0 Hz, 3H, CH3); 2.2 (m, 1H, CHMe2); 5.53 (dd, 3j(H-H) = 4.7 Hz,
~J(H-P) 332.4 Hz, PH). ~3C NMR (CDC13): 8 19.84 (s, CH3); 20.54 (s, c n 3 ) ;
29.40 (d, 1j(C-P)= 25.7 Hz, PCH); 196.52 (d, 2J(C-P)= 6.7 Hz, cis-CO); 199.25
(d, 2j(C-P) = 21.4 Hz, trans-CO) ppm. IR (decalin): ~,(CO) 2070m, 1940vs cm -1.
Mass spectrum (184W) m/z 476 (M, 42%), 392 ( M - 3CO, 100%).
Hydrogenation of complex 6 (Z + E): entry 4, Table 1
Complex 7 was obtained in 77% yield after 1 h of reaction in CH2C12 with
Rla(diphos)+PF6-- as catalyst: colorless oil; 31p NMR (hexane):
8
-31. 9
(1j(31p-183W)--229 Hz). 1H NMR (CDC13): 8 0.89 (d, ~/(H-H)= 7.0 Hz, 3H,
CH3); 0.92 (d, 3j(H-H) = 7.8 Hz, 3H, CH3); 1.6 (m, 1H, CHMe2); 1.8-2.2 (m, 2H,
PCH2); 5.74 (ddd, ~J(H-P) = 336.2 Hz, 3j(H-H) = 8.9 Hz, 3j(H-H) = 5.1 Hz, PH).
13C NMR (CDC13): /i 22.58 (d, ~/(C-P)= 6.8 Hz, CH3); 23.71 (d, 3j(C-P)= 7.9
Hz, CH3); 26.67 ~d, 2j(C-P)= 4.2 Hz, CHMe2); 39.27 (d, 1j(C-P)--24.0 Hz,
PCH2); 196.30 (d, ~J(C-P) = 7.0 Hz, cis-CO); 199.22 (d, 2j(C-P) = 21.0 Hz, trans-
CO) ppm. Mass spectrum (184W) m/z 490 (M, 28%), 406 ( M - 3CO, 79%), 348
(100%). Anal. Found; C, 36.98; H, 3.35. C15H15OsPW calcd.: C, 36.76; H, 3.08%.
Deuteration of complex 6 (Z + E): reaction 4
The same procedure was used as for hydrogenation but with D2 ill place of H2.
After 6 h at room temperature in the presence of 10% Rh(diphos)+PF6- as catalyst,
complex 10 was obtained in 82% yield. Starting from a mixture of the (Z) and (E)
isomers of complex 6 with a Z/E ratio of about 70/30, two isomers of 10 were
obtained in a similar ratio. The superposition of the 1H NMR signals prevented the
accurate measurement of the isomer ratio. Complex 10: colorless oil; 31p NMR
(C6D6): 8 - 37.53 (t, 1J~P-D) = 51.3 Hz). 1H NMR (C6D6): 8 0.59 (d, 3J(H-H) -- 6.7
Hz, 3H, CH3); 0.62 (d, J ( H - H ) -- 6.7 Hz, 3H, CH3); 1.5 (m, 1H, CHMe2); 1.60 (d)
and 1.75 (t) (1H, PCHD-two isomers). 13C NMR (C6D6): 8 22.46 (d, 3 j ( C - P ) =
7.0 Hz, CH3); 23.40 (d, ~/(C-P)= 7.8 nz, CH3); 26.60 (d, 2j(C-P)= 3.5 Hz,
CHMe2); 38.39 (m, 1j(C-D)-~J(C-P)= 23 Hz); 196.73 (d, 2j(C-P) 6.5 Hz,
cis-CO); 199.53 (d, 2j(C-P) = 20.1 Hz, trans-CO) ppm. Mass spectrum (la4W) m/z
492 (M, 42%), 408 ( M - 3CO, 98%), 348 (100%).
Vaumas, Rene de
