A Single Terminal [NiII−OH] Catalyst for Direct Julia‐Type Olefination and α‐Alkylation Involving Sulfones and Alcohols

Abstract

AbstractA terminal [NiII−OH] complex 1, supported by triflamide‐functionalized NHC ligands, showed divergent reactivity for the reaction of sulfone with alcohol, contingent on base concentration, temperature, and time. Julia‐type olefination of alcohols with sulfones was achieved using one equiv. of base, whereas lowering base loading to 0.5 equiv. afforded α‐alkylated sulfones. Besides excellent substrate scope and selectivity, biologically active stilbene derivatives DMU‐212, pinosylvin, resveratrol, and piceatannol were synthesized in high yield under Julia‐type olefination conditions. An extensive array of controlled experiments and DFT calculations provide valuable insight on the reaction pathway.