Ahlburg NL, Hergert O, Jones PG, Werz DB. Donor-Acceptor Cyclopropanes: Activation Enabled by a Single, Vinylogous Acceptor.
Angew Chem Int Ed Engl 2023;
62:e202214390. [PMID:
36322458 PMCID:
PMC10099577 DOI:
10.1002/anie.202214390]
[Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2022] [Indexed: 11/05/2022]
Abstract
A novel class of highly activated donor-acceptor cyclopropanes bearing only a single, vinylogous acceptor is presented. These strained moieties readily undergo cycloadditions with aldehydes, ketones, thioketones, nitriles, naphth-2-ols and various other substrates to yield the corresponding carbo- and heterocycles. Diastereocontrol can be achieved through the choice of catalyst (Brønsted or Lewis acid). The formation of tetrahydrofurans was shown to be highly enantiospecific when chiral cyclopropanes are employed. A series of mechanistic and kinetic experiments was conducted to elucidate a plausible catalytic cycle and to rationalize the stereochemical outcome.
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