Herein we report the enantioselective N-heterocyclic carbene catalyzed (4+2) annulation of the dienyl acyl azolium with enolates. The reaction exploits readily accessible acyl fluorides and TMS enol ethers to give a range of highly enantio- and diastereo-enriched cyclohexenes (most > 97:3 er and > 20:1 dr). The reaction was found to require high nucleophilicity NHC catalysts with mechanistic studies supporting a stepwise 1,6-addition/beta-lactonization.
机构:
Univ Jaume 1, Inst Adv Mat, Ave Vicente Sos Baynat S-N, E-12071 Castellon de La Plana, SpainUniv Jaume 1, Inst Adv Mat, Ave Vicente Sos Baynat S-N, E-12071 Castellon de La Plana, Spain
机构:
Indian Inst Chem Technol, Div Organ Chem 2, Hyderabad 500607, Andhra Pradesh, IndiaIndian Inst Chem Technol, Div Organ Chem 2, Hyderabad 500607, Andhra Pradesh, India