Indium(III) Catalyzed Direct sp3-sp C-C Bond Formation from Alcohols and Terminal Alkynes

A simple and efficient indium(III)-catalyzed sp(3)-sp C-C bond formation reaction via direct coupling of alcohols with terminal alkynes has been developed under mild conditions without any ligand, base or additive, in which both of aromatic and aliphatic alkynes and various alcohols such as benzylic, allylic and propargylic alcohols can be tolerated. This simple reaction system provides an attractive approach to a large number of internal alkynes in moderate to good yields, and only generates H2O as the side product.