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Rh-Catalyzed Aziridine Ring Expansions to Dehydropiperazines.

ABSTRACT: Piperazines are prevalent in pharmaceuticals and natural products, but traditional methods do not typically introduce stereochemical complexity into the ring. To expand access to these scaffolds, we report Rh-catalyzed ring expansions of aziridines and N-sulfonyl-1,2,3-triazoles to furnish dehydropiperazines with excellent diastereocontrol. Productive ring expansion proceeds via a pseudo-1,4-sigmatropic rearrangement of an aziridinium ylide species. However, the structural features of the carbene precursor are important, as pyridotriazoles undergo competing cheletropic extrusion to furnish ketimines.

SUBMITTER: Dequina HJ

PROVIDER: S-EPMC8025198 | biostudies-literature | 2020 May

REPOSITORIES: biostudies-literature

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Rh-Catalyzed Aziridine Ring Expansions to Dehydropiperazines.

Dequina Hillary J HJ Eshon Josephine J Raskopf William T WT Fernández Israel I Schomaker Jennifer M JM

Organic letters 20200422 9

Piperazines are prevalent in pharmaceuticals and natural products, but traditional methods do not typically introduce stereochemical complexity into the ring. To expand access to these scaffolds, we report Rh-catalyzed ring expansions of aziridines and <i>N-</i>sulfonyl-1,2,3-triazoles to furnish dehydropiperazines with excellent diastereocontrol. Productive ring expansion proceeds via a pseudo-1,4-sigmatropic rearrangement of an aziridinium ylide species. However, the structural features of the ...[more]

PMID: 32320259

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