Development of Chiral, Bifunctional Thiosquaramides: Enantioselective Michael Additions of Barbituric Acids to Nitroalkenes
作者:Michael Rombola、Chintan S. Sumaria、Thomas D. Montgomery、Viresh H. Rawal
DOI:10.1021/jacs.7b01115
日期:2017.4.19
nonpolar solvents than their oxosquaramide counterparts, and they are excellent catalysts for the unreported, enantioselective conjugate addition reaction of the barbituric acid pharmacaphore to nitroalkenes, delivering the chiral barbiturate derivatives in high yields and high enantioselectivities, even with catalyst loadings as low as 0.05 mol%.
A mild and convenient one-pot two-step synthesis of hydroxy- iminodihydrobenzofurans mediated by silica gel under microwave activation conditions
作者:Deepak Kumar Barange、B. Rama Raju、Veerababurao Kavala、Chun-Wei Kuo、Yu-Chen Tu、Ching-Fa Yao
DOI:10.1016/j.tet.2010.03.051
日期:2010.5
A convenient one-pot two-step procedure for the synthesis of hydroxyiminodihydrobenzofurans assisted by microwave irradiation in presence of silica gel is described herein. Cyclic 1,3-dicarbonyl compounds reacted smoothly with various nitroolefins to furnish hydroxyiminodihydrobenzofuran derivatives as the mixture of E and Z isomers. Clean reaction conditions, no work-up procedure, easy isolation and
Synthesis of Bicyclic Isoxazoles and Isoxazolines via Intramolecular Nitrile Oxide Cycloaddition
作者:Wen-Chang Chen、Veerababurao Kavala、Yu-Hsuan Shih、Yu-Hsuan Wang、Chun-Wei Kuo、Tang-Hao Yang、Chia-Yu Huang、Hao-Hsiang Chiu、Ching-Fa Yao
DOI:10.3390/molecules200610910
日期:——
An efficient and straight forward procedure for the syntheses of bicyclic isoxazole/isoxazoline derivatives from the corresponding dimethyl-2-(2-nitro-1-aryl/alkyl)-2-(prop-2-yn-1yl)malonates or dimethyl 2-allyl-2-(2-nitro-1-aryl/alkyl ethyl)malonate is described. High yields and simple operations are important features of this methodology.
Prolylprolinol-Catalyzed Asymmetric Michael Addition of Aliphatic Aldehydes to Nitroalkenes
作者:Dengfu Lu、Yuefa Gong、Weizhou Wang
DOI:10.1002/adsc.200900687
日期:2010.3.8
Several novel prolylprolinol catalysts have been designed and synthesized. This type of compound showed high catalytic efficiency on promoting the direct addition of unmodified aldehydes to nitroalkenes. Among the catalysts surveyed, the least bulky member (8d) exhibited the best performance on both efficiency and stereoselectivity, providing the products with up to 97% ee value with 1.5–5 mol% catalyst