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A versatile catalyst system for enantioselective synthesis of 2-substituted 1,4-benzodioxanes.

ABSTRACT: We report the synthesis of enantiomerically enriched 1,4-benzodioxanes containing alkyl, aryl, heteroaryl, and/or carbonyl substituents at the 2-position. The starting 1,4-benzodioxines were readily synthesized via ring closing metathesis using an efficient nitro-Grela catalyst at ppm levels. Excellent enantioselectivities of up to 99:1 er were obtained by using the versatile catalyst system [Ir(cod)Cl]2/BIDIME-dimer in the asymmetric hydrogenation of 2-substituted 1,4-benzodioxines. Furthermore, DFT calculations reveal that the selectivity of the process is controlled by the protonation step; and coordinating groups on the substrate may alter the interaction with the catalyst, resulting in a change in the facial selectivity.

SUBMITTER: Chong E

PROVIDER: S-EPMC6472100 | biostudies-literature | 2019 Apr

REPOSITORIES: biostudies-literature

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A versatile catalyst system for enantioselective synthesis of 2-substituted 1,4-benzodioxanes.

Chong Eugene E Qu Bo B Zhang Yongda Y Cannone Zachary P ZP Leung Joyce C JC Tcyrulnikov Sergei S Nguyen Khoa D KD Haddad Nizar N Biswas Soumik S Hou Xiaowen X Kaczanowska Katarzyna K Chwalba Michał M Tracz Andrzej A Czarnocki Stefan S Song Jinhua J JJ Kozlowski Marisa C MC Senanayake Chris H CH

Chemical science 20190313 15

We report the synthesis of enantiomerically enriched 1,4-benzodioxanes containing alkyl, aryl, heteroaryl, and/or carbonyl substituents at the 2-position. The starting 1,4-benzodioxines were readily synthesized via ring closing metathesis using an efficient nitro-Grela catalyst at ppm levels. Excellent enantioselectivities of up to 99:1 er were obtained by using the versatile catalyst system [Ir(cod)Cl]2/BIDIME-dimer in the asymmetric hydrogenation of 2-substituted 1,4-benzodio ...[more]

PMID: 31057761

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