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.
A new transition-metal-free reductive deoxygenative olefination of phosphorus ylides with CO2, an abundant and sustainable C1 chemical feedstock, is described. This catalytic CO2 fixation afforded β-unsubstituted acrylates and vinyl ketones in good yields with broad scope and good functional group tolerance under mild reaction conditions. Cost-effective and easily handled polymethylhydrosiloxane was
Palladium‐Catalyzed Cyclizative Borylation of Allenyl Ketones through Carbene Boryl Migratory Insertion: Access to Densely Substituted Furyl Boronates
作者:Kang Wang、Yan Xu、Jianbo Wang
DOI:10.1002/chem.202203697
日期:2023.3
A highly efficient Pd-catalyzed cyclizative borylation reaction of allenyl ketones has been developed. The transformation is based on carbene boryl migratoryinsertion using starting materials that are modularly assembled from raw building blocks. This borylation reaction is a reliable method to synthesize various borylated furans, from which previously hard-to-obtain tetra-substituted furans can be