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Enhancing the selectivity of prolinamide organocatalysts using the mechanical bond in [2]rotaxanes.

ABSTRACT: The synthesis of a pair of switchable interlocked prolinamides and their use as organocatalysts in three different enamine-activated processes are reported. A diacylaminopyridine moiety was incorporated into the thread for directing [2]rotaxane formation further allowing the association of complementary small molecules. The rotaxane-based systems were tested as organocatalysts in asymmetric enamine-mediated processes, revealing a significantly improved catalytic ability if compared with the non-interlocked thread. The presence of an electron-withdrawing nitro group at the macrocycle helps to achieve high conversions and enantioselectivities. These systems are able to interact with N-hexylthymine as a cofactor to form supramolecular catalysts displaying a divergent catalytic behaviour. The presence or absence of the cofactor controls the chemoselectivity in competitive reactions.

SUBMITTER: Calles M

PROVIDER: S-EPMC8152698 | biostudies-literature | 2020 Mar

REPOSITORIES: biostudies-literature

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Enhancing the selectivity of prolinamide organocatalysts using the mechanical bond in [2]rotaxanes.

Calles María M Puigcerver Julio J Alonso Diego A DA Alajarin Mateo M Martinez-Cuezva Alberto A Berna Jose J

Chemical science 20200311 14

The synthesis of a pair of switchable interlocked prolinamides and their use as organocatalysts in three different enamine-activated processes are reported. A diacylaminopyridine moiety was incorporated into the thread for directing [2]rotaxane formation further allowing the association of complementary small molecules. The rotaxane-based systems were tested as organocatalysts in asymmetric enamine-mediated processes, revealing a significantly improved catalytic ability if compared with the non- ...[more]

PMID: 34094051

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