Cu(I)-catalyzed synthesis of spiro[isoquinoline-4,2'-[1,3]oxazin]-3-ones via ring expansion reactions of isoxazoles with 4-diazoisoquinolin-3-ones

Abstract

Herein, we report a copper(I)-catalyzed ring expansion reaction of isoxazoles with 4-diazoisoquinolin-3-ones, furnishing a series of densely substituted novel spiro[isoquinoline-4,2'- [1,3]oxazin]-3-ones in good to excellent yields. Broad substrate scope, readily available starting materials, cheap catalyst, mild reaction conditions and scalability are the prominent features of this methodology.