The gold(I) complex (MeAuPPh3) was found to be a highly effective catalyst for the hydrative cyclization of 1,6-diynes to form the corresponding 3-methyl hex-2-enone derivatives with good to excellent yield. The proposed mechanism is described.
Gold-catalyzed hydrative cyclization of terminal 1,6-diynes proceeds in ionic liquid with methanol as co-solvent. The solvent-catalyst could be recycled, after separation of the product by extraction with ether.