Mn 2 (CO) 10 and UV light: a promising combination for regioselective alkene hydrosilylation at low temperature.

The low temperature regioselective hydrosilylation of various alkenes with (1,1,1,3,5,5,5-heptamethyltrisiloxane) MD H M is described using Mn 2 (CO) 10 under UV irradiation with Mn loadings as low as 1 mol%, in the absence of additives and with excellent selectivity and yields. The generation of a manganese radical allowed the anti-Markovnikov hydrosilylation products to be selectively obtained in yields up to 99%.