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
Reactions of Enamines with Selectfluor: A Straightforward Route to Difluorinated Carbonyl Compounds
作者:Weimin Peng、Jean'ne M. Shreeve
DOI:10.1021/jo0506837
日期:2005.7.1
Reactions of enamines, preformed from β-dicarbonyl and monocarbonyl compounds, with Selectfluor (1-chloromethyl-4-fluoro-1,4-diazoniabicyclo[2.2.2]octane bis(tetrafluoroborate) under mild conditions (triethylamine (TEA) or molecular sieves) easily led to the corresponding difluorinated carbonylcompounds in high yields.
A systematic study was performed on the preparation of unknown 2-C-(β-D-glucopyranosyl)pyrimidines. Pinner type cyclisation of O-perbenzylated C-(β-D-glucopyranosyl)formamidine with β-ketoesters, dimethyl malonate, and β-diketone derived α,β-unsaturated β-chloroketones followed by catalytic hydrogenation resulted in various substituted 2-C-(β-D-glucopyranosyl)-pyrimidin-4(3H)-ones, and 2-C-(β-D-glucopyranosyl)-4