Regiodivergent hydrosilylation in the nickel(0)-catalyzed cyclization of 1,6-enynes

Abstract

The divergent nickel(0)-catalyzed hydrosilylation/cyclization of 1,6-enynes has been developed, providing an efficient synthetic route for vinyl silanes or alkyl silanes from the same starting materials.

Recent Advances in Cyclization Reactions of 1,6‐Enynes

“…In 2022, the Bai and Chang group presented a nickel‐catalyzed cyclization protocol for the assembly of valuable alkyl silanes or vinyl silanes (Scheme 53). [44] This regiodivergent hydrosilylation reaction, which employed carbon‐, oxygen‐ or nitrogen‐tethered 1,6‐enynes as the substrates and silanes as coupling partners, provided the functionalized organosilanes in moderate to good yields with excellent diastereoselectivity.…”

Silanes as a versatile hydride source for Ni–H catalysis: a promising tool for π-hydro functionalization

“…Two different methods were developed for this reaction from the same starting materials, where a simple nickel catalyst delivered the vinyl silanes and the combination of ligand L59 with the nickel catalyst afforded alkyl silanes with excellent regio-and diastereoselectivities (Scheme 61). 96 Most recently, Fu's group developed a NiH-catalyzed reaction of racemic alkyl halides with prochiral 1,3-enynes to afford enantioenriched allenes. The chiral PyrOx ligand (L60) could catalyse the coupling of an alkyl electrophile to generate a C-C bond with the control of both central and axial chirality.…”

“…Two different methods were developed for this reaction from the same starting materials, where a simple nickel catalyst delivered the vinyl silanes and the combination of ligand L59 with the nickel catalyst afforded alkyl silanes with excellent regio- and diastereo-selectivities (Scheme 61). 96…”

Cobalt-Catalyzed Cyclization/Hydrosilylation Reaction of 1,6-Diynes Enabled by an Oxidative Cyclization–Hydrosilylation Mechanism

“…Intrigued by the economical and environmentally benign feature of late 3d metals, there has been great interest in late 3d metal-catalyzed cyclization/hydrosilylation reactions in recent years. The efforts have led to the development of late 3d metal-catalyzed cyclization/hydrosilylation reactions of enynes. − In contrast, progress in the cyclization and hydrosilylation of diynes is virtually unknown. To our knowledge, Tamao’s Ni-catalyzed reaction of 1,7-diynes with hydrosilanes, which furnishes six-membered ring-fused silyl dienes, is the sole example of the type (Scheme b). , The Ni-based catalytic system shows broad scope on hydrosilanes but is inapplicable to the cyclization/hydrosilylation of 1,6-diynes (Scheme b).…”