ChemInform Abstract: Iridium‐Catalyzed Asymmetric Allylic Etherification and Ring‐Closing Metathesis Reaction for Enantioselective Synthesis of Chromene and 2,5‐Dihydrobenzo[b]oxepine Derivatives.

Abstract

Iridium-catalyzed asymmetric etherifications of allylic carbonates with 2-vinylphenols and 2-allylphenols were realized. With a catalyst generated from 2 mol% of [Ir(cod)Cl]2 (cod=cycloocta-1,5-diene) and 4 mol% of the phosphoramidite ligand L2, the etherification products were obtained in excellent ees and then subjected to the ring-closing metathesis reaction providing an efficient synthesis of enantioenriched 2H-chromene and 2,5-dihydrobenzo[b]oxepine derivatives.