Work

Modular Synthesis of Dehydroprolines by an Energy‐Transfer Enabled Cloke‐Wilson Rearrangement

Year: 2024

Type: article

Abstract: A one-pot photocatalytic method is reported for the generation of dehydroprolines, valuable precursors to 5-aryl prolines. Imines, obtained via simple condensation of aminocyclopropane carboxylates (ACPC) with a broad range of aldehydes, were employed in this transformation without purification. We demonstrate this energy-transfer (EnT) enabled Cloke-Wilson-type rearrangement affords both the rare 1,2-dehydroprolines or the more thermodynamically favored 1,5-isomers with up to >20 : 1 selectivity in both directions, using an identical catalytic system from the same starting material. Syntheses of intermediates of bioactive molecules in high yields and selectivity highlight this enabling transformation. Mechanistic studies support the proposed triplet-triplet EnT mode of activation, distinct from the previously developed singlet excited states accessed via UV excitation.

Source: Angewandte Chemie International Edition

DOI: 10.1002/anie.202417025

Authors: Austin D. Marchese, Tomislav Rovis

Institution: Columbia University

Language: English

Topic: Radical Photochemical Reactions

Subfield: Organic Chemistry

Field: Chemistry

Domain: Physical Sciences

Open Access status: green

Funders: National Institutes of Health, National Institute of General Medical Sciences

Awards: G6595826480, Selective Functionalization of Aliphatic Amines