A direct catalyticasymmetricaddition of acetonitrile to aldehydes that realizes over 90 % ee is the ultimate challenge in alkylnitrile addition chemistry. Herein, we report achieving high enantioselectivity by the strategic use of a sterically demanding NiII pincer carbene complex, which afforded highly enantioenriched β‐hydroxynitriles. This highly atom‐economical process paves the way for exploiting
Imidazolium-based organoiridium-functionalized periodic mesoporous organosilica boosts enantioselective reduction of α-cyanoacetophenones, α-nitroacetophenones, and β -ketoesters
作者:Boxin Deng、Wei Xiao、Cuibao Li、Feng Zhou、Xuelin Xia、Tanyu Cheng、Guohua Liu
DOI:10.1016/j.jcat.2014.09.019
日期:2014.12
microscopy confirms a highly ordered dimensional-hexagonal mesostructure. This bifunctional heterogeneous catalyst displays excellent catalytic performance in the enantioselective reduction of α-cyano and α-nitroacetophenones. As expected, incorporation of imidazolium-functionality within hydrophobic periodic mesoporous organosilica promotes catalytic activity and enantioselectivity. In addition, this heterogeneous
Enantioselective Reduction of α-Cyano and α-Nitro Substituted Acetophenones Promoted by a Bifunctional Mesoporous Silica
作者:Boxin Deng、Tanyu Cheng、Meng Wu、Jinyu Wang、Guohua Liu
DOI:10.1002/cctc.201300340
日期:2013.10
Pores that put your reaction in a spin! A recoverable mesoporoussilica exhibits excellent catalytic activity and enhanced enantioselectivity for the reduction of α‐cyano and α‐cyanoacetophenones that ascribes the synergistic effect of its phase‐transfer functionalized cetyltrimethylammonium bromide and confined chiral organoiridium catalytic nature.
Unexpected Stereorecognition in Nitrilase-Catalyzed Hydrolysis of β-Hydroxy Nitriles
作者:Sukanta Kamila、Dunming Zhu、Edward R. Biehl、Ling Hua
DOI:10.1021/ol061542+
日期:2006.9.1
Biocatalytic enantioselective hydrolysis of beta-hydroxy nitriles to corresponding (S)-enriched beta-hydroxy carboxylic acids has been achieved for the first time by an isolated nitrilase bll6402 from Bradyrhizobium japonicum USDA110. This offers a new "green" approach to optically pure beta-hydroxy nitriles and beta-hydroxy carboxylic acids. The observed remote stereorecognition is surprising because
Chemo- and Stereoselective Reduction of an α-Cyanoketone by Bakers' Yeast at Low Temperature
作者:Peter Florey、Andrew J. Smallridge、Abilio Ten、Maurie A. Trewhella
DOI:10.1021/ol990833y
日期:1999.12.1
[formula: see text] The bakers' yeast mediated reduction of 3-oxo-3-phenylpropanenitrile (1) proceeds at 4 degrees C to give exclusively (S)-3-hydroxy-3-phenylpropanenitrile (3) in 59% yield. This is in contrast to the corresponding reaction at room temperature which yields a mixture of reduction and alkylation products. This work demonstrates the use of low temperature to improve yeast selectivity.