Iron-Catalyzed Reductive Vinylation of Tertiary Alkyl Oxalates with Activated Vinyl Halides
作者:Yang Ye、Haifeng Chen、Ken Yao、Hegui Gong
DOI:10.1021/acs.orglett.0c00561
日期:2020.3.6
of vinylated allcarbonquaternary centers via Fe-catalyzed cross-electrophile coupling of vinyl halides with tertiary alkyl methyl oxalates. The reaction displays excellent functional group tolerance and broad substrate scope, which allows cascade radical cyclization and vinylation to afford complex bicyclic and spiral structural motifs. The reaction proceeds via tertiary alkyl radicals, and the putative
An enantioselective sulfa‐Michael‐cyclization reaction was developed for the synthesis of 1,5‐benzothiazepines with versatile pharmacological activities. The reaction between 2‐aminothiophenol and α,β‐unsaturated pyrazoleamides gave direct access to N−H‐free 1,5‐benzothiazepines in the presence of a chiral N,N′‐dioxide/Yb(OTf)3 complex. Excellent enantioselectivities (up to 96 % ee) and high yields
cathode surface, protonation, and radical cross-coupling process, resulting in a variety of valuable pyridine variants, which contain a tertiary and even a quaternary carbon at the α-position of pyridines, in high yields. The employment of thioesters to the conjugated alkenes enables no requirement of catalyst and high temperature, representing a highly sustainable synthetic method.
Rh(III)-Catalyzed Decarboxylative Coupling of Acrylic Acids with Unsaturated Oxime Esters: Carboxylic Acids Serve as Traceless Activators
作者:Jamie M. Neely、Tomislav Rovis
DOI:10.1021/ja412444d
日期:2014.2.19
α,β-Unsaturated carboxylic acids undergo Rh(III)-catalyzed decarboxylative coupling with α,β-unsaturated O-pivaloyl oximes to provide substituted pyridines in good yield. The carboxylic acid, which is removed by decarboxylation, serves as a traceless activating group, giving 5-substituted pyridines with very high levels of regioselectivity. Mechanistic studies rule out a picolinic acid intermediate
cycloaddition of β-substituted ene- and thioenecarbamates as well as cyclic enamides with quinone diimides catalyzed by a BINOL- and SPINOL-derived phosphoric acid is reported. A wide variety of 2,3-disubstituted 2-aminoindolines, including polycyclic ones, were prepared in generally high yields (up to 98%) with moderate to complete diastereoselectivities and in most cases excellent enantioselectivities