Efficient Assembly of Allenes, 1,3‐Dienes, and 4<i>H</i>‐Pyrans by Catalytic Regioselective Nucleophilic Addition to Electron‐Deficient 1,3‐Conjugated Enynes

Abstract

Organic building blocks: From a starting material of electron-deficient 1,3-conjugate enynes 1 (see scheme; EWG=electron-withdrawing group), it is possible to make three types of useful organic building blocks (1,2-allenes, 1,3-dienes, and 4H-pyrans) regioselectively, by a simple choice of different nucleophiles.