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Palladium-catalyzed intramolecular enantioselective C(sp3)–H insertion of donor/donor carbenes† † Electronic supplementary information (ESI) available. CCDC 2142261, 1908561 and 2142262. For ESI and crystallographic data in CIF or other electronic format see https://doi.org/10.1039/d2sc03524c

ABSTRACT: Herein, the first palladium-catalyzed intramolecular enantioselective C(sp3)–H insertion reaction of donor–donor carbenes has been successfully achieved. This facile protocol enables the rapid construction of a collection of enantioenriched decorated indolines with two contiguous stereocenters in a single step. Both enynones and diazo compounds are efficient donor–donor carbene precursors for this reaction. By an adjustment of ligands and protecting groups of the substrates, the palladium–carbene intermediates from diazo compounds afford sparse trans-indolines with excellent enantioselectivities, while carbenes from enynones deliver cis-indolines exclusively. Based on the control reactions and Hammett analysis, a stepwise Mannich-type pathway through a short-lived and compact zwitterionic intermediate is proposed. The first palladium-catalyzed intramolecular enantioselective C(sp3)–H insertion of donor–donor carbenes has been achieved. The diazo compounds afford rare trans-indolines with excellent enantioselectivities, while enynones deliver cis-indolines exclusively.

SUBMITTER: Li W

PROVIDER: S-EPMC9629006 | biostudies-literature | 2022 Sep

REPOSITORIES: biostudies-literature

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