Synthesis of substituted nitroolefins: a copper catalyzed nitrodecarboxylation of unsaturated carboxylic acids
作者:Balaji V. Rokade、Kandikere Ramaiah Prabhu
DOI:10.1039/c3ob41408f
日期:——
A novel, mild and convenient method for the nitrodecarboxylation of substituted cinnamic acid derivatives to their nitroolefins is achieved using a catalytic amount of CuCl (10 mol%) and tert-butyl nitrite (2 equiv.) as a nitrating agent in the presence of air. This reaction provides a useful method for the synthesis of β,β-disubstituted nitroolefin derivatives, which are generally difficult to access from other conventional methods. Additionally, this reaction is selective as the E-isomer of the acid derivatives furnishes the corresponding E-nitroolefins. One more salient feature of the method is, unlike other methods, no metal nitrates or HNO3 are employed for the transformation.
Carboxylative Cyclization of 2-Butenoates with Carbon Dioxide: Access to Glutaconic Anhydrides
作者:Ke Zhang、Wen-Zhen Zhang、Xue-Yan Tao、Min Zhang、Wei-Min Ren、Xiao-Bing Lu
DOI:10.1021/acs.joc.0c01717
日期:2020.9.4
Cyclic anhydrides are versatile synthons and functional comonomers. Herein, we reported an organic base-promoted carboxylative cyclization of 2-butenoates with carbon dioxide to produce important glutaconic anhydrides in good yields. This metal-free reaction showed broad substrate scopes and proceeded under mild reaction conditions.
N-Heterocyclic Carbene-Catalyzed Cyclization of Unsaturated Acyl Chlorides and Ketones
作者:Li-Tao Shen、Pan-Lin Shao、Song Ye
DOI:10.1002/adsc.201100178
日期:2011.8
synthesis of optically active trifluoromethyl dihydropyranones and spirocyclic oxindole-dihydropyranones has been realized by the chiral N-heterocyclic carbenes-catalyzed cyclization of α,β-unsaturated β-methylacyl chlorides with activated trifluoromethyl ketones or isatin derivatives.
Water-Enabled Catalytic Asymmetric Michael Reactions of Unreactive Nitroalkenes: One-Pot Synthesis of Chiral GABA-Analogs with All-Carbon Quaternary Stereogenic Centers
作者:Jae Hun Sim、Choong Eui Song
DOI:10.1002/anie.201611466
日期:2017.2.6
new catalytic reactions for otherwise unreactive substrate systems. Under the “on water” reaction conditions, extremely unreactive β,β‐disubstituted nitroalkenes smoothly underwent enantioselective Michael addition reactions with dithiomalonates using a chiral squaramide catalyst, affording both enantiomers of highly enantioenriched Michael adducts with all‐carbon‐substituted quaternarycenters. The