par De Smet, Gilles 
;Bai, Xingfeng;Mensch, Carl;Sergeyev, S;Evano, Gwilherm ;Maes, Bert U. W.
Référence Angewandte Chemie International Edition in English, 61, e202201751
Publication Publié, 2022-04-04
;Bai, Xingfeng;Mensch, Carl;Sergeyev, S;Evano, Gwilherm ;Maes, Bert U. W.Référence Angewandte Chemie International Edition in English, 61, e202201751
Publication Publié, 2022-04-04
Article révisé par les pairs
| Résumé : | Acetate serves as a renewable and easily installed leaving group for selective deoxygenation of phenolics (ArOH). Ni-catalyzed hydrodeacetoxylation of aryl acetates (Ar - OAc) with HBpin in a green carbonate solvent selectively delivers the corresponding deoxygenated arenes (ArH). The method is also applicable to highly challenging guaiacyl and syringyl acetates, leaving -OMe groups intact without arene reduction. Renewable 4-propylguaiacol obtained from pine can also be transformed without significant loss in yield versus oil derived feedstock. The observed chemoselectivity for Ar - OAc versus ArO - Ac bond cleavage was rationalized based on mechanistic experiments and DFT calculations. ArOH side-product formation is attributed to direct competitive Ni-catalyzed reduction of the C=O bond. Hydrodeacyloxylation of a set of aryl alkanoates featured interesting chemoselectivity with a dramatic influence of the length and structure of the alkyl chain on catalysis. |
