Ph3PCN2: A stable reagent for carbon-atom transfer

• 成果类型: Article
• 署名作者: Koike, Taichi; Yu, Jhen-Kuei; Hansmann, Max M.
• 署名单位: Dortmund University of Technology
• 刊物名称: SCIENCE
• ISSN/ISSBN: 0036-10579
• DOI: 10.1126/science.ado4564
• 发表日期: 2024-07-19
• 页码: 305-311
• 关键词: terminal alkynes; n-isocyanoiminotriphenylphosphorane; phosphacumulene ylides; functional isocyanides; coordination chemistry; metal-complexes; carbodicarbenes; reactivity; hexaphenylcarbodiphosphorane; activation

摘要

Precise modification of a chemical site in a molecule at the single-atom level is one of the most elegant yet difficult transformations in chemistry. A reagent specifically designed for chemoselective introduction of monoatomic carbon is a particularly formidable challenge. Here, we report a straightforward, azide-free synthesis of a crystalline and isolable diazophosphorus ylide, Ph3PCN2, a stable compound with a carbon atom bonded to two chemically labile groups, triphenylphosphine (PPh3) and dinitrogen (N-2). Without any additives, the diazophosphorus ylide serves as a highly selective transfer reagent for fragments, including Ph3PC, to deliver phosphorus ylide-terminated heterocumulenes and CN2 to produce multisubstituted pyrazoles. Ultimately, even exclusive carbon-atom transfer is possible. In reactions with aldehydes and acyclic and cyclic ketones (R2C=O), the carbon-atom substitution forms a vinylidene (R2C=C:) en route to alkynes or butatrienes.