Asymmetric Friedel−Crafts Alkylation of Pyrroles with Nitroalkenes Using a Dinuclear Zinc Catalyst
摘要:
The catalytic enantioselective and atom economic Friedel-Crafts alkylation of pyrroles with nitroalkenes under mild reaction conditions using a dinuclear zinc catalyst is reported. The versatility of the reaction is demonstrated by the conversion of a number of differentially substituted nitroalkenes with differentially substituted pyrroles. Tandem addition reactions to form 2,5-disubstituted pyrroles are also demsonstrated. All pyrrole alkylations have been carried out without using N-protecting groups, which also enhances the efficiency by which substituted pyrroles may be synthesized. The reactions result in good yields and excellent enantioselectivities.
Conformational change in a urea catalyst induced by sodium cation and its effect on enantioselectivity of a Friedel-Crafts reaction
作者:Arjun K. Chittoory、Gayatri Kumari、Sudip Mohapatra、Partha P. Kundu、Tapas K. Maji、Chandrabhas Narayana、Sridhar Rajaram
DOI:10.1016/j.tet.2014.03.068
日期:2014.5
indeed in an unfavorable conformation. Infrared and Raman spectroscopic studies show that sodium binds the catalyst through the carbonyl and sulfonyl groups. Simulated IR and Raman spectra match well with the experimentally recorded spectra, thereby corroborating the proposed conformational change. This result shows that weak Lewis acids can be used to tune the conformation of hydrogen-bonding catalysts
Enantioselective and Regioselective Friedel-Crafts Alkylation of Pyrroles with Nitroalkenes Catalyzed by a Tridentate Schiff Base-Copper Complex
作者:Fengfeng Guo、Dalu Chang、Guoyin Lai、Tao Zhu、Shunshun Xiong、Sujing Wang、Zhiyong Wang
DOI:10.1002/chem.201102206
日期:2011.9.26
On a (pyr)role: A mild and highly efficientcatalytic system has been developed for the asymmetric Friedel–Crafts alkylation of pyrroles with nitroalkenes (see scheme). High yields, and excellent enantioselectivities and regioselectivities were obtained for a broad range of substrates. The synthetic utility of this methodology and mechanisticstudies involving a novel, negative, nonlinear effect are
A heterotrimetallic Pd–Sm–Pd complex for asymmetric Friedel–Crafts alkylations of pyrroles with nitroalkenes
作者:Guoqi Zhang
DOI:10.1039/c2ob25074h
日期:——
Catalytic asymmetric FriedelâCrafts alkylations of pyrroles and nitroalkenes were carried out by using a novel heterotrimetallic PdâSmâPd catalyst based on a simple chiral ligand 1, to give the adducts with high yields and up to 93% ee.
Enantioselective Michael Addition of Pyrroles with Nitroalkenes in Aqueous Media Catalyzed by a Water-Soluble Catalyst
作者:Yang Gui、Yanan Li、Jianan Sun、Zhenggen Zha、Zhiyong Wang
DOI:10.1021/acs.joc.8b01141
日期:2018.7.20
A new water-soluble catalytic system was developed and used in an enantioselectiveMichaeladdition of pyrroles with nitroalkenes in water to afford nitroethylpyrrole derivatives with both excellent yields and ee values.