Title :

Deeper Mechanistic Insight into Ru Pincer-Mediated Acceptorless Dehydrogenative Coupling of Alcohols: Exchanges, Intermediates, and Deactivation Species

Author(s) :

Nguyen, Duc Hanh [Auteur]
Unité de Catalyse et Chimie du Solide - UMR 8181 [UCCS]
Trivelli, Xavier [Auteur]
Unité de Glycobiologie Structurale et Fonctionnelle UMR 8576 [UGSF]
Capet, Frederic [Auteur]
Unité de Catalyse et Chimie du Solide - UMR 8181 [UCCS]
Swesi, Youssef [Auteur]
Laboratoire de Génie des Procédés Catalytiques [LGPC]
Favre-Réguillon, Alain [Auteur]
Laboratoire de Génie des Procédés Catalytiques [LGPC]
Vanoye, Laurent [Auteur]
Laboratoire de Génie des Procédés Catalytiques [LGPC]
Dumeignil, Franck [Auteur]
Unité de Catalyse et Chimie du Solide - UMR 8181 [UCCS]
Gauvin, Regis [Auteur]
Unité de Catalyse et Chimie du Solide - UMR 8181 [UCCS]

Journal title :

ACS Catalysis

Volume number :

8

Pages :

4719-4734

Publication date :

2018

English keyword(s) :

Alcohols
Organic compounds
Aldehydes
Ethyl groups
Ethanol

HAL domain(s) :

Chimie/Catalyse

English abstract : [en]

The mechanism of acceptorless dehydrogenative coupling reaction (ADC) of alcohols to esters catalyzed by aliphatic pincer PHNP ruthenium complexes was experimentally studied. Relevant intermediate species involved in the ...
Show more >The mechanism of acceptorless dehydrogenative coupling reaction (ADC) of alcohols to esters catalyzed by aliphatic pincer PHNP ruthenium complexes was experimentally studied. Relevant intermediate species involved in the catalytic cycle were isolated and structurally characterized by single-crystal X-ray diffraction studies, and their reactivity (including toward substrates related to the catalytic process) was probed. VT NMR studies unveiled several chemical exchanges connecting the Ru amido hydride, the Ru alkoxide, and the alcohol substrate. Under catalytic conditions, in situ IR spectroscopy monitoring demonstrated the production of ester via aldehyde as intermediate. A Tishchenko-like pathway is proposed as the main path for the production of ester from aldehyde, involving alkoxide and hemiacetaloxide Ru species (the latter being identified in the reaction mixture by NMR). Catalytic system deactivation under base-free conditions was found to be related to water traces in the reaction medium (either as impurity or derived from aldol reactions) that lead to the formation of catalytically inactive acetato Ru complexes. These react with alkali metal alkoxides to afford catalytically active Ru species. In line with this observation, running the ADC reaction in the presence of water scavengers or alkoxides allows maintaining sustained catalytic activity.Show less >

Language :

Anglais

Audience :

Internationale

Popular science :

Non

Administrative institution(s) :

ENSCL
CNRS
Centrale Lille
Univ. Artois
Université de Lille

Collections :

• Unité de Catalyse et Chimie du Solide (UCCS) - UMR 8181
• Unité de Glycobiologie Structurale et Fonctionnelle (UGSF) - UMR 8576

Research team(s) :

Catalyse et synthèse éco-compatible (CASECO)
Valorisation des alcanes et de la biomasse (VAALBIO)

Submission date :

2019-09-25T14:37:53Z
2020-02-11T11:43:12Z
2020-09-25T10:35:03Z