A Bifunctional Photoaminocatalyst for the Alkylation of Aldehydes: Design, Analysis, and Mechanistic Studies

[EN] A bifunctional photoaminocatalyst based on imidazolidinone and thioxanthone is presented. The preparation of these catalysts proceeds in a two-step synthesis that allows an easy tuning of the steric properties. The photophysical and electrochemical data of the imidazolidinone photocatalysts hav...

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Bibliographic Details
Authors: Rigotti, Thomas, Casado Sánchez, Antonio, Cabrera, Silvia, Líras, Marta, De la Peña-O'Shea, Víctor, Alemán, José, Pérez-Ruiz, Raúl|||0000-0003-1136-3598
Format: article
Publication Date:2018
Country:España
Institution:Universitat Politècnica de València (UPV)
Repository:RiuNet. Repositorio Institucional de la Universitat Politécnica de Valéncia
Language:English
OAI Identifier:oai:riunet.upv.es:10251/192953
Online Access:https://riunet.upv.es/handle/10251/192953
Access Level:Open access
Keyword:Bifunctional photocatalyst
Organocatalysis
Pyrrolidines
Photochemistry
Mechanism
QUIMICA ORGANICA
Description
Summary:[EN] A bifunctional photoaminocatalyst based on imidazolidinone and thioxanthone is presented. The preparation of these catalysts proceeds in a two-step synthesis that allows an easy tuning of the steric properties. The photophysical and electrochemical data of the imidazolidinone photocatalysts have been determined, indicating that the catalysts can work under visible light conditions. To corroborate the experimental observations, ground state geometry optimization and energy transition studies of thioxanthone and bifunctional catalyst 4c were optimized by time-dependent density functional theory (TD DFT) calculations. The alkylation of aldehydes with this photoaminocatalyst works with high enantioselectivities and yields due to the stereoelectronic properties of the catalyst. A rational mechanistic cycle based on different mechanistic experiments, TD DFT calculations, and laser flash photolysis is presented.