Highly Regioselective Sequential 1,1-Dihydrosilylation of Terminal Aliphatic Alkynes with Primary Silanes: Highly Regioselective Sequential 1,1-Dihydrosilylation of Terminal Aliphatic Alkynes with Primary Silanes†

main observation and conclusion A regioselective double 1,1-hydrosilylation of terminal aliphatic alkynes with primary silanes catalyzed by one cobalt catalyst has been developed. gem-Bis(dihydrosilyl)alkanes containing four silicon-hydrogen bonds are efficiently constructed in an atom-economical manner. Tolerated substrates include simplest alkyne-ethyne, a complicated drug derivative and various functionalized terminal aliphatic alkynes. Asymmetric approach using two catalysts is achieved with excellent enantioselectivities to access corresponding chiral products. The transformations of Si-H bonds into Si-C, Si-O, and Si-F bonds and the synthesis of enantioriched alpha-hydroxysilane show synthetic utility.