Ni-catalyzed regioselective C-C bond formation of 1,1-disubstituted allenes with aldehydes

Abstract

Allenes, despite their structural resemblance to alkenes and alkynes, exhibit unique reactivity due to the orthogonal arrangement of their cumulative π-bonds, making precise allene selectivity an emerging area of interest. Previous studies on Ni-catalyzed coupling reactions between allenes and aldehydes yielded diverse regioselectivities, with nucleophilic and reductive conditions producing different outcomes. In this work, we developed a regioselective method for generating linear products through coupling at the terminal carbon of 1,1-disubstituted allenes using photoredox/Ni-dual catalysis. We achieved the regioselectivity by strategically modifying substrate patterns and the catalytic system employing an unconventional P^N ligand. This work represents a notable advancement in selective catalysis, offering valuable insights into the control of allene reactivity. © 2024 The Royal Society of Chemistry.