Bifunctional thiourea-modified polymers of intrinsic microporosity for enantioselective α-amination of 3-aryl-2-oxindoles in batch and flow conditions?

Organic & Biomolecular Chemistry Pub Date: 2020-10-31 DOI: 10.1039/D0OB01373K

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.

Graphical abstract: Bifunctional thiourea-modified polymers of intrinsic microporosity for enantioselective α-amination of 3-aryl-2-oxindoles in batch and flow conditions
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