Bifunctional thiourea-modified polymers of intrinsic microporosity for enantioselective α-amination of 3-aryl-2-oxindoles in batch and flow conditions. Issue 45 (6th November 2020)

• Record Type: Journal Article
• Authors: Martín, Laura; Maestro, Alicia; Andrés, José M.; Pedrosa, Rafael
• Is Part Of: Organic & biomolecular chemistry. Volume 18:Issue 45(2020)
• Page Start: 9275
• Page End: 9283
• Publication Date: 2020-11-06
• Subjects: Chemistry, Organic -- Periodicals; Bioorganic chemistry -- Periodicals; Chemistry, Physical organic -- Periodicals; 547
• DOI: 10.1039/d0ob01373k
• Languages: English
• ISSNs: 1477-0520

Abstract

Abstract : A multigram scale preparation of enantioenriched 3-aryl-3-amino-2-oxindoles promoted by a novel chiral bifunctional thiourea, readily prepared from polymers of intrinsic microporosity. Abstract : Two novel polymers of intrinsic microporosity decorated with chiral thioureas have been used as recoverable organocatalysts in enantioselective α-amination of 3-aryl-substituted oxindoles, creating a quaternary stereocenter. Both catalysts were able to promote the reaction in excellent yields and good enantioselection. Catalyst II, with a pyridyl nucleus, was used in recycling experiments maintaining the activity without additional reactivation, and in flow processes allowing the synthesis of the amination product in multigram scale.