The reduction of organic halides with tributyltin hydride in the presence of a catalytic amount of triethylborane has been studied. (1) Alkyliodides and alkyl bromides reacted easily with tin hydride at −78°C to give the corresponding hydrocarbons, while alkyl chlorides were sluggish to react and recovered unchanged. (2) The reduction of alkenyl halides such as 1-deuterio-1-iodo-1-dodecene and 1-
Triethylborane Induced Stereoselective Radical Addition of R<sub>3</sub>SiH to Acetylenes and Stereoselective Reduction of Alkenyl Iodides with Tris(trimethylsilyl)silane
Triethylborane induced radical addition of various organosilanes (R3SiH) to acetylenes has been studied. Among them, tris(trimethylsilyl)silane (TTMSS) proved to be the best reagent for the hydrosilylation of acetylenic compounds in terms of yield and stereoselectivity. For instance, reaction of 1-dodecyne with TTMSS at room temperature for 3 h under Et3B catalyst provided (Z)-1-tris(trimethylsilyl)silyl-1-dodecene
The reduction of alkenyl halides with tributyltinhydride in the presence of a catalytic amount of tetrakis(triphenylphosphine)palladium has been studied. Alkenyl iodides reacted easily with tributyltinhydride at 25°C to give the corresponding hydrocarbons stereoselectively. However, the reaction of alkenyl bromides were sluggish at 25°C and needed heating at 75°C to complete.
Dimethylphenylsilyl group is removed from a vinyl carbon with tetrabutylammonium fluoride. The presence of phenyl group on silicon atom plays a critical role. The cleavage of allyldimethylsilyl- and alkoxydimethylsilyl groups also proceeds very easily.