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Conformational Control of Chiral Amido-Thiourea Catalysts Enables Improved Activity and Enantioselectivity.

ABSTRACT: While aryl pyrrolidinoamido-thioureas derived from ?-amino acids are effective catalysts in a number of asymmetric transformations, they exist as mixtures of slowly interconverting amide rotamers. Herein, the compromising role of amide bond isomerism is analyzed experimentally and computationally. A modified catalyst structure that exists almost exclusively as a single amide rotamer is introduced. This modification is shown to result in improved reactivity and enantioselectivity by minimizing competing reaction pathways.

SUBMITTER: Lehnherr D

PROVIDER: S-EPMC5096793 | biostudies-literature | 2016 Jul

REPOSITORIES: biostudies-literature

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Conformational Control of Chiral Amido-Thiourea Catalysts Enables Improved Activity and Enantioselectivity.

Lehnherr Dan D Ford David D DD Bendelsmith Andrew J AJ Kennedy C Rose CR Jacobsen Eric N EN

Organic letters 20160613 13

While aryl pyrrolidinoamido-thioureas derived from α-amino acids are effective catalysts in a number of asymmetric transformations, they exist as mixtures of slowly interconverting amide rotamers. Herein, the compromising role of amide bond isomerism is analyzed experimentally and computationally. A modified catalyst structure that exists almost exclusively as a single amide rotamer is introduced. This modification is shown to result in improved reactivity and enantioselectivity by minimizing co ...[more]

PMID: 27294369

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