Enantioselective Organocatalytic Alkylation of Aldehydes and Enals Driven by the Direct Photoexcitation of Enamines

Melchiorre, Paolo; Silvi, Mattia; Cassani, Carlo; Arceo, Elena; Jurberg, Igor D.

Abstract

Disclosed herein is a photo-organocatalytic enantioselective α- and γ-alkylation of aldehydes and enals, respectively, with bromomalonates. The chemistry uses a commercially available aminocatalyst and occurs under illumination by a fluorescent light bulb in the absence of any external photoredox catalyst. Mechanistic investigations reveal the previously hidden ability of transiently generated enamines to directly reach an electronically excited state upon light absorption while successively triggering the formation of reactive radical species from the organic halides. At the same time, the ground state chiral enamines provide effective stereochemical induction for the enantioselective alkylation process.

Citation

Melchiorre, P., Silvi, M., Cassani, C., Arceo, E., & Jurberg, I. D. (2015). Enantioselective Organocatalytic Alkylation of Aldehydes and Enals Driven by the Direct Photoexcitation of Enamines. Journal of the American Chemical Society, 137(19), 6120-6123. https://doi.org/10.1021/jacs.5b01662

• Journal Article Type: Article
• Acceptance Date: Mar 8, 2015
• Online Publication Date: Mar 11, 2015
• Publication Date: May 20, 2015
• Deposit Date: Jan 29, 2020
• Journal: Journal of the American Chemical Society
• Print ISSN: 0002-7863
• Electronic ISSN: 1520-5126
• Publisher: American Chemical Society
• Peer Reviewed: Peer Reviewed
• Volume: 137
• Issue: 19
• Pages: 6120-6123
• DOI: https://doi.org/10.1021/jacs.5b01662
• Public URL: https://nottingham-repository.worktribe.com/output/3826751
• Publisher URL: https://pubs.acs.org/doi/10.1021/jacs.5b01662