ChemInform Abstract: Iridium Catalyzed Carbocyclizations: Efficient (5 + 2) Cycloadditions of Vinylcyclopropanes and Alkynes.

Abstract

Iridium Catalyzed Carbocyclizations: Efficient (5 + 2) Cycloadditions of Vinylcyclopropanes and Alkynes. -The first examples of iridium-catalyzed inter-and intramolecular vinylcyclopropane-alkyne (5+2) cycloadditions are reported. DFT modeling suggests that catalysis by iridium(I) proceeds through a mechanism similar to that previously reported for rhodium(I)-catalyzed vinylcyclopropane-alkyne cycloadditions, but a smaller free energy span for iridium enables substantially faster catalysis under favorable conditions. The system is characterized by up to quantitative yields and is amenable to an array of disubstituted alkynes and vinylcyclopropanes. -(MELCHER, M.-C.; VON WACHENFELDT, H.; SUNDIN, A.; STRAND*, D.; Chem. -Eur. J. 21 (2015) 2, 531-535, http://dx.