Cp2ZrCl2-Catalyzed cycloalumination of acetylenic alcohols and propargylamines by Et3Al

The Cp2ZrCl2-catalyzed cycloalumination of acetylenic alcohols and propargylamines by Et3Al was studied. The process affords 2,3-disubstituted alumacyclopent-2-enes, which were identified by the analysis of the products of their deuterolysis and hydrolysis. The cycloalumination of alkyl- and phenyl-substituted propargylamines proceeds with high regio- and stereoselectivity to give the corresponding allylamine derivatives in high yield. Unlike the phenyl derivatives, the cycloalumination of alkyl-substituted acetylenic alcohols (propargyl, homopropargyl, and bishomopropargyl alcohols) is not regioselective.