Phosphonium salts and phosphoranes. Part 5. Thermal and electron-impact induced fragmentation of heteroaroylmethylenetriphenylphosphoranes.
作者:Judith M. Brittain、R.Alan Jones、Sayed Ali Naghi Taheri
DOI:10.1016/s0040-4020(01)90373-4
日期:1992.9
synthesis of five-membered heteroarylethynes. The electron-impact induced fragmentation of the phosphoranes also produced ions corresponding in mass to the ethynes, but metastable ion data indicate that the extrusion of the ethyne follows the initial loss of H· from the molecularion.
The present invention relates to a Sonogashira-Carbonylation reaction using two types of gas, as well as novel crystals which can control a heat of the said reaction and the process of producing the same. In addition, the present invention relates to a ligand (additive) to prevent the deactivation of a palladium catalyst.
Synthesis of Unsymmetrically Substituted 1,3-Butadiynes and 1,3,5-Hexatriynes via Alkylidene Carbenoid Rearrangements
作者:Annabelle L. K. Shi Shun、Erin T. Chernick、Sara Eisler、Rik R. Tykwinski
DOI:10.1021/jo026481h
日期:2003.2.1
Unsymmetrically substituted 1,3-butadiynes and 1,3,5-hexatriynes are synthesized in four steps from commercially available aldehydes or carboxylic acids. The key step in this process involves a Fritsch-Buttenberg-Wiechell rearrangement, in which an alkylidene carbenoid intermediate subsequently rearranges to the desired polyyne. This rearrangement proceeds under mild conditions, and it is tolerant