Unexpected catalytic activity of simple triethylborohydrides in the hydrosilylation of alkenesElectronic supplementary information (ESI) available: Experimental procedures and analytical data of isolated compounds. See DOI: 10.1039/c7cc01531c

The first example of sodium triethylborohydride-catalysed hydrosilylation of alkenes is reported. The hydrosilylation of certain alkenes, in particular styrenes, vinylsilanes and allyl glycidyl ether, with aromatic hydrosilanes proceeded in a highly regioselective manner to give Markovnikov products. It is significant that several protocols use NaHBEt 3 as a reducing agent generating active catalysts in situ of other hydrosilylation reactions. An anionic mechanism of hydrosilylation is proposed. Highly regioselective hydrosilylation of olefins with aryl- and alkoxysilanes has been developed using a simple sodium triethylborohydride.