Rh<sup>II</sup>-Catalyzed [3+2] Cycloaddition of 2 <i>H</i>-Azirines with<i>N</i>-Sulfonyl-1,2,3-Triazoles
作者:Yun-Zhou Zhao、Hai-Bin Yang、Xiang-Ying Tang、Min Shi
DOI:10.1002/chem.201406460
日期:2015.2.23
RhII‐catalyzed intermolecular [3+2] cycloaddition of 2 H‐azirines with N‐sulfonyl‐1,2,3‐triazoles is disclosed, in which a series of fully functionalized pyrroles is produced via rhodium azavinyl carbene intermediates. A distinct feature of this reaction is that the azavinyl carbene serves as a [2C] equivalent, instead of as [1 C] or aza‐[3C] synthons, which have been reported previously in cyclopropanations
Base-Induced Transformation of 2-Acyl-3-alkyl-2<i>H</i>-azirines to Oxazoles: Involvement of Deprotonation-Initiated Pathways
作者:Yingtang Ning、Yuko Otani、Tomohiko Ohwada
DOI:10.1021/acs.joc.7b00904
日期:2017.6.16
intermediate possessing methyl substituents at C(3) appears to be more stable than the tautomeric nitrile ylide which was proposed to be involved in photoinduced and pyrolysis reactions of 2-acyl-3-alkyl-2H-azirines to afford oxazoles. Thus, intermediacy of ketenimine is consistent with both experimental and computational results, at least under strongly basic reaction conditions.
Copper(I)-catalyzed N–O bondformation reactions through vinyl nitrene-mediated pathway were described. The reactions of N-alkoxylbenzamides and 2H-azirines afforded α-amino oxime ethers in good to excellent yields at room temperature, which involved the cleavage of C–N and N–O bonds and the construction of new N–O and C–N bonds. It offers an efficient, regio- and stereoselective synthetic route for