Silver‐Mediated Cascade Synthesis of Functionalized 1,4‐Dihydro‐2<i>H</i>‐benzo‐1,3‐oxazin‐2‐ones from Carbon Dioxide

Abstract

Abstract A conceptually novel catalytic domino approach is presented for the synthesis of highly functional 1,4‐dihydro‐2 H ‐1,3‐benzoxazine‐2‐one derivatives. Key to the chemoselectivity is a proper design of the precursor to override thermodynamically favored parasitic cyclization processes and empower the formation of the desired product through Thorpe–Ingold effects. The synthetic diversity of these CO 2 ‐based heterocycles is further demonstrated, and the isolation of a reaction intermediate supports an unusual ring‐expansion sequence from an α‐alkylidene, five‐membered cyclic carbonate to a six‐membered cyclic carbamate by N‐induced isomerization.

Topics & Concepts