Copper(I)-catalyzed stereoselective hydrogenation of 1,3-diynes and enynes

Abstract A stereoselective hydrogenation of 1,3-diynes with an air-stable copper(I)/N-heterocyclic carbene complex, [IPrCuOH], has been developed. The corresponding products, 1,3-dienes, are obtained in a stereoselective manner depending on their substitution pattern: Diaryl-diynes yield E,E -1,3-dienes, whereas dialkyl-diynes are converted to the corresponding Z,Z -1,3-dienes. Hydrogenation and deuteration experiments with enynes indicate that these are competent reaction intermediates in the hydrogenation of diynes.