Catalytic Asymmetric [4+1] Cyclization of <i>ortho</i>‐Quinone Methides with 3‐Chlorooxindoles

Abstract

Abstract In this work, we established catalytic asymmetric [4+1] cyclization of ortho ‐quinone methides ( o ‐QMs) with 3‐chlorooxindoles and a catalytic asymmetric domino oxidation/[4+1] cyclization reaction of 2‐alkylphenols with 3‐chlorooxindoles, which constructed a spirooxindole‐based 2,3‐dihydrobenzofuran scaffold in good yield (up to 97%), with excellent diastereoselectivity (up to &gt;95:5 dr ) and high enantioselectivity (up to 99% ee ). This work is not only the first highly enantioselective [4+1] cyclization of o ‐QMs but has also realized the first catalytic asymmetric domino [4+1] cyclization of o ‐QMs. In addition, both of the reactions provide efficient stereoselective methods for constructing spirooxindole‐based 2,3‐dihydrobenzofuran scaffolds with optical purity. magnified image