A Metal–Ligand Cooperative Pathway for Intermolecular Oxa‐Michael Additions to Unsaturated Nitriles1. (6th February 2015)

• Record Type: Journal Article
• Authors: Perdriau, Sébastien; Zijlstra, Douwe S.; Heeres, Hero J.; de Vries, Johannes G.; Otten, Edwin
• Is Part Of: Angewandte Chemie. Volume 127:Number 14(2015)
• Page Start: 4310
• Page End: 4314
• Publication Date: 2015-02-06
• Subjects: Homogene Katalyse -- Michael‐Addition -- Pinzettenliganden -- Redoxaktive Liganden -- Ruthenium; Chemistry -- Periodicals; 540
• DOI: 10.1002/ange.201412110
• Languages: English
• ISSNs: 0044-8249

Abstract

Abstract: An unprecedented catalytic pathway for oxa‐Michael addition reactions of alcohols to unsaturated nitriles has been revealed using a PNN pincer ruthenium catalyst with a dearomatized pyridine backbone. The isolation of a catalytically competent Ru–dieneamido complex from the reaction between the Ru catalyst and pentenenitrile in combination with DFT calculations supports a mechanism in which activation of the nitrile through metal–ligand cooperativity is a key step. The nitrile‐derived Ru‐N moiety is sufficiently Brønsted basic to activate the alcohol and initiate conjugate addition of the alkoxide to the α, β‐unsaturated fragment. This reaction proceeds in a concerted manner and involves a six‐membered transition state. These features allow the reaction to proceed at ambient temperature in the absence of external base.