Hydrogermylation initiated by trialkylborohydrides: a living anionic mechanism

Sodium trialkylborohydrides were found to be selective catalysts for the hydrogermylation of aromatic alkenes. Addition of phenylgermane and diphenylgermane in the presence of 10 mol% of NaHB(sec-Bu)3 proceeded in a highly selective manner to give - in contrast to the analogous hydrosilylation process - beta-germylated products. The nature of this process was explained with the aid of DFT calculations and it was proposed that the mechanism proceeds via a trisubstituted germanide anion whose attack on the terminal vinyl carbon is the source of selectivity.

Automated summary

Sodium trialkylborohydrides were confirmed as selective catalysts for hydrogermylation of aromatic alkenes. Addition of phenylgermane and diphenylgermane in the presence of 10 mol% NaHB(sec-Bu)3 showed high selectivity, producing beta-germylated products, in contrast to the hydrosilylation process. DFT calculations supported the mechanism proceeding through a trisubstituted germanide anion attacking the terminal vinyl carbon.