Rhodium-catalysed cyclic carbonylation of 2-alkynylphenols: synthesis of benzofuranones and coumarins
Abstract
Rhodium-catalysed carbonylation of 2-alkynylphenols 1 under water-gas shift reaction conditions gives benzofuranone derivatives 2 and coumarin derivatives 3 in high yield (up to 96%, 2∶3 = 65∶35), in which the hydroxy group adjacent to the carbon–carbon triple bond participitates in the cyclic carbonylation.