l-Proline Derived Secondary Aminothiourea Organocatalyst for Synthesis of Coumarin Derived Trisubstituted Methanes: Rate Enhancement by Bifunctional Catalyst over Cooperative Catalysis
作者:Grace Basumatary、Rahul Mohanta、Ghanashyam Bez
DOI:10.1007/s10562-019-02809-4
日期:2019.10
l-proline derived aminothioureas are being used as catalyst in asymmetric synthesis, their applications in multicomponent reactions are not yet reported in the literature. We report herein a l-proline derived secondary aminothiourea as a multifunctional catalyst in multicomponent reaction for synthesis of coumarin-based unsymmetrical trisubstituted methanes whose prototype has been found to be acetylcholinesterase
based chiralorganocatalystsderivedfrom l-proline have been developed to catalyze directaldolreactions between cyclohexanone and aromatic aldehydes in water. Under the optimal conditions, high yields (up to 95%), enantioselectivities (up to 90%), and moderate diastereoselectivities (up to 65:35) were obtained. Considering the catalytic inefficiency of sole proline for the aldolreaction in water
Novel supported and unsupported prolinamides as organocatalysts for enantioselective cyclization of triketones
作者:Rafael Pedrosa、José María Andrés、Rubén Manzano、César Pérez-López
DOI:10.1016/j.tetlet.2013.03.123
日期:2013.6
A novel prolylsulfonamide derived from ethylene diamine and its supported counterpart has been prepared and tested as enantioselective intramolecular aldol reaction of cyclic and acyclic triketones. Good to excellent yields and enantioselectivities have been obtained in water and under solvent free conditions. (C) 2013 Elsevier Ltd. All rights reserved.