Stereoselective synthesis of vinylsilanes from alkynylsilanes via hydromagnesiation. Application to a synthesis of 7(E)-dodecenyl acetate and dihydrojasmone

A facile stereoselective synthesis of (E)-α-silylvinylstannanes via hydromagnesiation of alkynylsilanes

“…The hydromagnesiation of alkynylsilanes 1 at 25°C in ether is almost 100% regio-and stereoselective as previously described [15]. We observed that the Mg/Sn metathesis reaction on intermediates 2 occurs with total retention of the configuration.…”

“…Mitchell et al [14] described that the alkynes underwent the regio-and stereospecific addition with (trimethylsilyl)trialkylstannanes in the presence of Pd(PPh 3 ) 4 catalyst to give (Z)-b-silylvinylstannanes. Hydromagnesiation has emerged as a unique hydrometallation with some attractive features such as the high regioselectivity and stereoselectivity observed with alkynylsilanes [15]. We now wish to report that (E)-asilylvinylstannanes could be synthesized by hydromagnesiation of alkynylsilanes, followed by treatment with trialkylstannyl chlorides (Scheme 1).…”

A facile stereoselective synthesis of (E)‐1,2‐disubstituted vinylic selenides via hydromagnesiation of alkylarylacetylenes

“…Hydromagnesiation has emerged as a unique hydrometallation with some attractive features such as the high regioselectivity and stereoselectivity observed with alkylarylacetylenes [8] and alkynylsilanes [9]. Very recently, we have reported the stereoselective syntheses of (E)-allylic alcohols [10], (E)-␣-selenenylvinylsilanes [11], 1,3-dienylsilanes [12], and (E)-␣-aryltellurenylvinylsilanes [13].…”

Stereoselective Synthesis of (E)-α-Selenenylvinylsilanes via the Hydromagnesiation Reaction of Alkynylsilanes

“…Hydromagnesiation has emerged as a unique hydrometalation with some attractive features, such as the high regioselectivity and stereoselectivity observed with alkynylsilanes. 3,4 We now wish to report that (E)-aselenenylvinylsilanes could be synthesized by hydromagnesiation of alkynylsilanes, followed by treatment with selenenyl bromides.Alkynylsilanes 1 were prepared according to the literature procedure. 5 Hydromagnesiation of alkynylsilanes at 25 °C in diethyl ether for 6 hours gave (Z)-a-silylvinyl Grignard reagents 2, which reacted with selenenyl bromides 3 in THF to afford (E)-a-selenenylvinylsilanes 4.…”

“…Hydromagnesiation has emerged as a unique hydrometalation with some attractive features, such as the high regioselectivity and stereoselectivity observed with alkynylsilanes. 3,4 We now wish to report that (E)-aselenenylvinylsilanes could be synthesized by hydromagnesiation of alkynylsilanes, followed by treatment with selenenyl bromides.…”