Asymmetric Organocatalysis and Photoredox Catalysis for the α-Functionalization of Tetrahydroisoquinolines
Hong Hou, Shaoqun Zhu, Iuliana Atodiresei, Magnus Rueping
Index: 10.1002/ejoc.201800117
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Abstract
The asymmetric α-alkylation of tetrahydroisoquinolines with cyclic ketones has been accomplished in the presence of a combined catalytic system consisting of a visible-light photoredox catalyst and a chiral primary amine organocatalyst. The desired products were obtained in good yields, high enantioselectivity, and good to excellent diastereoselectivity. (PC: photoredox cycle, EN: enamine cycle). A combined photoredox/organocatalytic system for the asymmetric α-alkylation of tetrahydroisoquinolines (THIQs) has been developed. In this protocol, a chiral organocatalyst enables a high level of enantio- and diastereocontrol for the oxidative coupling reaction of THIQs with simple cyclic ketones.