en
Scientific article
English

Palladium-Catalyzed Long-Range Deconjugative Isomerization of Highly Substituted α,β-Unsaturated Carbonyl Compounds

Published inJournal of the American Chemical Society, vol. 138, no. 32, p. 10344-10350
Publication date2016
Abstract

The long-range deconjugative isomerization of a broad range of α,β-unsaturated amides, esters, and ketones by an in situ generated palladium hydride catalyst is described. This redox-economical process is triggered by a hydrometalation event and is thermodynamically driven by the refunctionalization of a primary or a secondary alcohol into an aldehyde or a ketone. Di-, tri-, and tetrasubstituted carbon–carbon double bonds react with similar efficiency; the system is tolerant toward a variety of functional groups, and olefin migration can be sustained over 30 carbon atoms. The refunctionalized products are usually isolated in good to excellent yield. Mechanistic investigations are in support of a chain-walking process consisting of repeated migratory insertions and β-H eliminations. The bidirectionality of the isomerization reaction was established by isotopic labeling experiments using a substrate with a double bond isolated from both terminal functions. The palladium hydride was also found to be directly involved in the product-forming tautomerization step. The ambiphilic character of the in situ generated [Pd–H] was demonstrated using isomeric trisubstituted α,β-unsaturated esters. Finally, the high levels of enantioselectivity obtained in the isomerization of a small set of α-substituted α,β-unsaturated ketones augur well for the successful development of an enantioselective version of this unconventional isomerization.

Research group
Citation (ISO format)
LIN, Luqing, ROMANO, Ciro, MAZET, Clement. Palladium-Catalyzed Long-Range Deconjugative Isomerization of Highly Substituted α,β-Unsaturated Carbonyl Compounds. In: Journal of the American Chemical Society, 2016, vol. 138, n° 32, p. 10344–10350. doi: 10.1021/jacs.6b06390
Main files (1)
Article (Published version)
accessLevelRestricted
Identifiers
ISSN of the journal0002-7863
430views
3downloads

Technical informations

Creation08/30/2016 11:08:00 AM
First validation08/30/2016 11:08:00 AM
Update time03/15/2023 12:40:53 AM
Status update03/15/2023 12:40:53 AM
Last indexation01/16/2024 9:38:08 PM
All rights reserved by Archive ouverte UNIGE and the University of GenevaunigeBlack