Department of Chemistry, Rice University, 6500 Main Street, Houston, TX, 77030, USA.
Life and Health Sciences Department, The University of North Texas at Dallas, 7400 University Hills Boulevard, Dallas, TX, 75241, USA.
Angew Chem Int Ed Engl. 2019 Oct 1;58(40):14219-14223. doi: 10.1002/anie.201909151. Epub 2019 Aug 29.
The Ti -mediated synthesis of spirocyclic NH-azetidines from oxime ethers using either an alkyl Grignard reagent or terminal olefin ligand exchange coupling partner is described. Through a proposed Kulinkovich-type mechanism, a titanacyclopropane intermediate forms and serves as a 1,2-aliphatic dianion equivalent, inserting into the 1,2-dielectrophilc oxime ether to ultimately give rise to the desired N-heterocyclic four-membered ring. This transformation proceeds in moderate yield to furnish previously unreported and structurally diverse NH-azetidines in a single step.
本文描述了利用钛介导，通过肟醚与烷基格氏试剂或末端烯烃配体交换偶联试剂，合成螺环 NH-氮杂环丁烷的方法。通过一个提出的 Kulinkovich 型机理，形成钛杂环丙烷中间体，作为 1,2-脂肪族二负离子等价物，插入 1,2-二电性肟醚中，最终得到所需的 N-杂环四元环。该转化以中等收率进行，可在一步中得到以前未报道的结构多样的 NH-氮杂环丁烷。
