Unexpected C–C bond cleavage of epoxide motif: Rhodium(<scp>i</scp>)-catalyzed tandem heterocyclization/[4+1] cycloaddition of 1-(1-alkynyl)oxiranyl ketones
作者:Tao Wang、Cui-Hong Wang、Junliang Zhang
DOI:10.1039/c0cc05650b
日期:——
A rhodium(I)-catalyzed tandem heterocyclization and formal [4+1] cycloaddition of 1-(1-alkynyl)oxiranyl ketones was developed, which provides a general, efficient and practical route to highly substituted furo[3,4-b]furan-3(2H)-ones, wherein the epoxide motif undergo unexpected C-C bond cleavage rather than the classical C-O bond cleavage.
Organocatalytic hetero [4+2] cycloaddition reactions of 2-(1-alkynyl)-2-alkene-1-ones: metal-free access to highly substituted 4H-pyrans
作者:Xiuzhao Yu、Zhongyan Cao、Junliang Zhang
DOI:10.1039/c0ob00334d
日期:——
Highly substituted 4H-pyrans can be smoothly synthesized from readily available 2-(1-alkynyl)-2-alkene-1-ones by DBU- or n-Bu3P catalyzed hetero-[4+2] cycloaddition reactions, in which 2-(1-alkynyl)-2-alkene-1-ones act as both heterodiene and heterodinenophile.
DBU-catalyzed tandem additions of electron-deficient 1,3-conjugated enynes with 2-aminomalonates: a facile access to highly substituted 2-pyrrolines
作者:Xiuzhao Yu、Guanghua Zhou、Junliang Zhang
DOI:10.1039/c2cc30840a
日期:——
An efficient, metal free approach to highly substituted 2-pyrrolines by DBU-catalyzed tandem additions (a formal [3+2] cycloaddition) of electron-deficient 1,3-conjugated enynes and 2-aminomalonates under mild conditions was developed.
Chemoselective CC Bond Cleavage of Epoxide Motifs: Gold(I)-Catalyzed Diastereoselective [4+3] Cycloadditions of 1-(1-Alkynyl)oxiranyl Ketones and Nitrones
作者:Tao Wang、Junliang Zhang
DOI:10.1002/chem.201002395
日期:2011.1.3
Cutting carbon! A novel facile strategy for the CCbondcleavage of oxiranylketones has been developed. Carbophilic gold(I) activation of the alkyne side chain mediates a heterocyclization and subsequent CCbondcleavage (see scheme).