Reactivity of 2-halo-2H-azirines. Part 3: Dehalogenation of 2-halo-2H-azirine-2-carboxylates
摘要:
The dehalogenation of 2-halo-3-phenyl-2H-azirine-2-carboxylates is described. Using sodium borohydride and tributyltin hydride 3-phenyl-2H-azirine-2-carboxylates were obtained in moderate yields. The synthesis of a new 2-bromo-2H-azirines with a chiral auxiliary, 10-phenylsulfonylisobornyl 2-bromo-3-phenyl-2H-azirine-2-carboxylate, is reported. Its dehalogenation led to 10-phenylsulfonylisobomyl 2H-azirine-2-carboxylate as single stereoisomer together with the formation of 10-phenylsulfonylisobomyl acetate. (C) 2003 Elsevier Science Ltd. All rights reserved.
Synthesis of Pyridines by Carbenoid-Mediated Ring Opening of 2<i>H</i>-Azirines
作者:Nicole S. Y. Loy、Alok Singh、Xianxiu Xu、Cheol-Min Park
DOI:10.1002/anie.201209301
日期:2013.2.18
a wide range of substituents on the resulting pyridinering using mild reaction conditions (see scheme; esp=α,α,α′,α′‐tetramethyl‐1,3‐benzenedipropionic acid). The formation of the key intermediate is catalyst‐controlled, and subsequent cyclization and oxidation affords pyridines in excellent yields. The method has been used for the efficient synthesis of polyarylpyridines.
Rh(<scp>ii</scp>)-catalyzed cycloadditions of 1-tosyl 1,2,3-triazoles with 2H-azirines: switchable reactivity of Rh-azavinylcarbene as [2C]- or aza-[3C]-synthon
作者:Yuanhao Wang、Xiaoqiang Lei、Yefeng Tang
DOI:10.1039/c5cc00268k
日期:——
The Rh(II)-catalyzed formal [3+2] and [3+3] cycloadditions of 1-tosyl 1,2,3-triazoles with 2H-azirines have been developed, which enable the efficient synthesis of polysubstituted 3-aminopyrroles and 1,2-dihydropyrazines, respectively. The reported [3+2] cycloaddition represents the first application of 1-sulfonyl 1,2,3-triazole as a [2C]-component in relevant cycloaddition reactions.
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
Domino transformation of isoxazoles to 2,4-dicarbonylpyrroles under Fe/Ni relay catalysis
作者:Ekaterina E. Galenko、Alexey V. Galenko、Alexander F. Khlebnikov、Mikhail S. Novikov
DOI:10.1039/c5ra01889g
日期:——
The domino reaction of 5-alkoxy- or 5-aminoisoxazoles, under metal relay catalysis, with symmetric 1,3-diketones gives 4-acylpyrrole-2-carboxylic acid derivatives in high yield.
It has been revealed that 1-azirines having an ester function at C can be synthesized by the thermally induced skeletal rearrangement of 5-alkoxyisoxazoles and 5-alkylmercaptoisoxazles. Characterization of the azirines obtained was made by chemical reactions as well as by spectrometry. A further thermal transformation of azirine esters into oxazole derivatives could not be found. Mass spectra of representative