Nickel-Catalyzed Stereospecific Alkylation of Vinylsiloxanes Using Pyridinium salts

A methodology for radical cross-coupling with vinylsiloxanes and pyridinium salts under nickel catalysis is described. Easily implemented from inexpensive and abundant primary amines and terminal alkynes, this modern Hiyama coupling provides efficient access to (E), (Z), and 1,1’-alkenes with configuration retention. Operating under mild conditions, this robust strategy applies to a broad range of functional groups with diverse double bond stereochemistries. This versatile reaction is scalable and straightforward, accommodating both secondary and primary alkyl groups. A radical mechanism involving hypervalent silicon intermediates is proposed.