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
The reaction of enamines with isoxazol-5-ones unsubstituted at the 4-position takes place in a manner similar to that with oxazol5-ones to give, in this case, the 4-alkenylisoxazol-5-olate salts of the appropriate amine. These salts are readily converted into the 4-alkylideneisoxazolones with hydrogen chloride. By using a mixture of ketone and base rather than the enamine, the same salts are obtained
Kineticvs. thermodynamiccontrol and steric hindrance are factors that determine the regioselectivity of the Pd(O)-catalyzed allylation of ambident heterocycles of the 3-hydroxyisoxazole, 5-isoxazolone and 5-pyrazolone series.
Synthesis of (?-substituted ?-aminophosphinic and ?-aminophosphonic acids
作者:T. I. Osipova、A. V. Belyankin、A. R. Khomutov、Yu. N. Zhukov、E. N. Khurs、R. M. Khomutov
DOI:10.1007/bf01431122
日期:1996.11
The reaction of ketoximes with hypophosphorous acid resulted in previously unknown α-substituted-α-aminophosphinic acids, which were oxidized into the corresponding α-substituted-α-aminophosphonic acids.