Regioselective Nucleophilic Addition of Organometallic Reagents to 3-Geminal Bis(silyl) N-Acyl Pyridinium

Abstract

A regioselective nucleophilic addition to 3-geminal bis(silyl) N-acyl pyridinium has been described. Geminal bis(silane) shows contrasting roles that lead to different regioselectivities for the addition of different nucleophiles: its steric effect dominates to favor 1,6-addition of alkyl, vinyl, and aryl organometallic reagents; its directing effect dominates to favor 1,2-addition of less sterically demanding alkynyl Grignard reagents.

Markovnikov-selective double hydrosilylation of challenging terminal aryl alkynes under cobalt and iron catalysis

“…5 Gem -bis(silanes) are gaining particularly increasing attention due to their unique reactivity 6 and structural properties. 7 However, access to these compounds and further development of their chemistry was hampered for a long time due to the scarcity of synthetic methods for placing two silyl groups on one carbon atom. 8 Gem -bis(silanes) that could be obtained with these protocols 8 had no Si–H bonds within the bis(silyl) moiety and the lack thereof could have been holding back further developments.…”