Open AccessRh-Catalyzed Aziridine Ring Expansions to Dehydropiperazines
Author(s) -
Hillary J. Dequina,
Josephine Eshon,
William T. Raskopf,
Israel Fernández,
Jennifer M. Schomaker
Publication year - 2020
Publication title -
organic letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.94
H-Index - 239
eISSN - 1523-7060
pISSN - 1523-7052
DOI - 10.1021/acs.orglett.0c01124
Subject(s) - chemistry , aziridine , ring (chemistry) , ylide , carbene , catalysis , combinatorial chemistry , stereochemistry , sulfonyl , organic chemistry , alkyl
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.