Group 14 Elements Hetero-Difunctionalizations via Nickel-Catalyzed Electroreductive Cross-Coupling

Abstract

The difunctionalization of unsaturated bonds plays a vital role in the enrichment of molecular complexity. While various catalytic methods for alkene and alkyne difunctionalization have been developed in recent years, hetero-functionalization the introduction of two different atoms has been less explored. This is mainly due to the challenges associated with achieving high chemo-, regio-, and stereoselectivity, especially when adding two similar atoms from the same group across unsaturated bonds. In this study, we describe a nickel-catalyzed, three-component reductive protocol for group 14 element hetero-difunctionalization of 1,3-enynes using electrochemistry. This new method is mild, selective, and general, allowing for the silyl-, germanyl-, and stannyl-alkylation of enynes. Various chlorosilanes as well as chlorogermans, and chlorostannanes can be successfully used in combination with aryl/alkyl-substituted 1,3-enynes and primary, secondary, and tertiary alkyl bromides in the electroreductive coupling.