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How mono- and diphosphine ligands alter regioselectivity of the Rh-catalyzed annulative cleavage of bicyclo[1.1.0]butanes.

ABSTRACT: Rh(I)-catalyzed cycloisomerizations of bicyclo[1.1.0]butanes provide a fruitful approach to cyclopropane-fused heterocycles. Products and stereochemical outcome are highly dependent on catalyst. The triphenylphosphine (PPh₃) ligand provides pyrrolidines, placing substituents anti to the cyclopropyl group. The 1,2-bis(diphenylphosphino)ethane (dppe) ligand yields azepanes with substituents syn to the cyclopropyl group. In this work, quantum mechanical DFT calculations pinpoint a reversal of regio- and diastereoselectivity, suggesting a concerted (double) C-C bond cleavage and rhodium carbenoid formation, driven by strain-release. The ligand-influenced cleavage step determines the regioselectivity of carbometalation and product formation, and suggests new applications of bicyclobutanes.

SUBMITTER: Chen PP

PROVIDER: S-EPMC9701199 | biostudies-literature | 2022 Nov

REPOSITORIES: biostudies-literature

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How mono- and diphosphine ligands alter regioselectivity of the Rh-catalyzed annulative cleavage of bicyclo[1.1.0]butanes.

Chen Pan-Pan PP Wipf Peter P Houk K N KN

Nature communications 20221126 1

Rh(I)-catalyzed cycloisomerizations of bicyclo[1.1.0]butanes provide a fruitful approach to cyclopropane-fused heterocycles. Products and stereochemical outcome are highly dependent on catalyst. The triphenylphosphine (PPh<sub>3</sub>) ligand provides pyrrolidines, placing substituents anti to the cyclopropyl group. The 1,2-bis(diphenylphosphino)ethane (dppe) ligand yields azepanes with substituents syn to the cyclopropyl group. In this work, quantum mechanical DFT calculations pinpoint a revers ...[more]

PMID: 36435835

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