[摘要]：Low-valent indium(I)-mediated nickel-catalyzed propargylation of aldehydes is described. The nickel/indium(I)-mediated reaction of propargylic carbonates possessing different substitution patterns afforded syn-homopropargylic alcohols in high yields upon coupling with a variety of carbonyl compounds. Both the nickel catalyst and the phosphane ligands were found to play a crucial role in this transformation. The diastereoselectivity is strongly dependent on the ligand employed. A mechanism involving umpolung of the propargylnickel intermediates under the influence of low-valent indium is proposed to account for the dependence of the stereochemical characteristics of the phosphane ligands. |
