We present the first base‐free Fe‐catalyzed ester reduction applying molecular hydrogen. Without any additives, a variety of carboxylic acid esters and lactones were hydrogenated with high efficiency. Computations reveal an outer‐sphere mechanism involving simultaneous hydrogen transfer from the iron center and the ligand. This assumption is supported by NMR experiments.
A novel catalytic hydrogen‐autotransfer protocol for the atom‐efficient α‐alkylation of ketones with readily available alcohols is presented. The use of manganese complexes bearing non‐innocent PNP pincer ligands enabled the functionalization of a broad range of valuable ketones, including 2‐oxindole, estrone 3‐methyl ether, and testosterone. Mechanistic investigations suggest the participation of
Unravelling the Mechanism of Basic Aqueous Methanol Dehydrogenation Catalyzed by Ru–PNP Pincer Complexes
作者:Elisabetta Alberico、Alastair J. J. Lennox、Lydia K. Vogt、Haijun Jiao、Wolfgang Baumann、Hans-Joachim Drexler、Martin Nielsen、Anke Spannenberg、Marek P. Checinski、Henrik Junge、Matthias Beller
DOI:10.1021/jacs.6b05692
日期:2016.11.16
Ruthenium PNP complex 1a (RuH(CO)Cl(HN(C2H4Pi-Pr2)2)) represents a state-of-the-art catalyst for low-temperature (<100 °C) aqueous methanoldehydrogenation to H2 and CO2. Herein, we describe an investigation that combines experiment, spectroscopy, and theory to provide a mechanistic rationale for this process. During catalysis, the presence of two anionic resting states was revealed, Ru-dihydride (3-)