Organocatalytic Biomimetic Reduction of Conjugated Nitroalkenes
作者:Peter Schreiner、Zhiguo Zhang
DOI:10.1055/s-2007-983805
日期:2007.8
A thiourea-catalyzed biomimetic reduction of conjugatednitroalkenes has been developed. Various aromatic and aliphatic conjugatednitroalkenes can be reduced to give the respective nitroalkanes with good yields under mild conditions. This protocol is not only practical, but may also provide insight into the mechanisms of redox transformations in biological systems.
Organocatalytic, Enantioselective Conjugate Addition of Nitroalkanes to Nitroolefins
作者:Jian Wang、Hao Li、Liansuo Zu、Wei Jiang、Wei Wang
DOI:10.1002/adsc.200600247
日期:2006.10
An organocatalytic, enantioselectiveconjugateaddition reaction of nitroalkanes with nitroolefins has been developed under neat conditions without using an organic solvent. The process, catalyzed by a modified Cinchona alkaloid, affords synthetically useful 1,3-dinitro compounds in good yields (70–82 %) with good degrees of enantioselectivity (67–88 % ee).
A straightforwardsynthesis of 1,2‐dicyanoalkanes by reacting nitroalkenes with trimethylsilyl cyanide in the presence of tetrabutylammoniumfluoride is described. The reaction proceeds through a tandem double Michael addition under mild conditions. Employing the hypervalent silicate generated from trimethylsilyl cyanide and tetrabutylammoniumfluoride is essential for achieving this transformation
motifs in organocatalysis, whereas efficient 1,3‐diamine‐derived organocatalysts are very rare. Herein we report a highly efficient camphor‐1,3‐diamine‐derived squaramideorganocatalyst. Its catalytic activity in Michaeladditions of 1,3‐dicarbonyl nucleophiles to trans‐β‐nitrostyrene derivatives provides excellent enantioselectivities (up to >99% ee).
Modular synthesis of cyclic cis- and trans-1,2-diamine derivatives
作者:Anna K. Weber、Josef Schachtner、Robert Fichtler、Timo M. Leermann、Jörg M. Neudörfl、Axel Jacobi von Wangelin
DOI:10.1039/c4ob00913d
日期:——
substituted nitroarenes. Reduction with Zn/HCl provides access to various trans- and cis-diaminocyclohexenes, respectively, in a straight-forward manner. With enantiopure secondary amines, a two-step synthesis of chiral nitrocyclohexadienes was developed (82–94% ee).