AbstractLow‐valent titanium readily prepared in situ from TiCl4 and Mg powder in THF is found to be an active agent for the reduction of amides which were previously considered to be inert towards low‐valent titanium. The reaction proceeds under very mild conditions, and is applicable to all types of amides, primary, secondary and tertiary, to produce the corresponding amines in good to excellent yields. This new finding provides a practical, convenient and general method for the important transformation of amides to amines. A plausible reaction mechanism is proposed.magnified image
Broadly Applicable Ytterbium-Catalyzed Esterification, Hydrolysis, and Amidation of Imides
作者:Céline Guissart、Andre Barros、Luis Rosa Barata、Gwilherm Evano
DOI:10.1021/acs.orglett.8b01896
日期:2018.9.7
An efficient, broadlyapplicable, operationally simple, and divergent process for the transformation of imides into a range of carboxylic acid derivatives under mild conditions is reported. By simply using catalytic amounts of ytterbium(III) triflate as a Lewis acid promoter in the presence of alcohols, water, amines, or N,O-dimethylhydroxylamine, a broad range of imides is smoothly and readily converted
Accessing <i>N</i>-Acyl Azoles via Oxoammonium Salt-Mediated Oxidative Amidation
作者:John M. Ovian、Christopher B. Kelly、Vincent A. Pistritto、Nicholas E. Leadbeater
DOI:10.1021/acs.orglett.7b00060
日期:2017.3.17
An operationally simple, robust, metal-free approach to the synthesis of N-acyl azoles from both alcohols and aldehydes is described. Oxidative amidation is facilitated by a commercially available organic oxidant (4-acetamido-2,2,6,6-tetramethylpiperidine-1-oxoammonium tetrafluoroborate) and proceeds under very mild conditions for an array of structurally diverse substrates. Tandem reactions of these
Phenylsilane as an active amidation reagent for the preparation of carboxamides and peptides
作者:Zheming Ruan、R. Michael Lawrence、Christopher B. Cooper
DOI:10.1016/j.tetlet.2006.08.024
日期:2006.10
The use of phenylsilane as a mild coupling reagent for amidation reactions is reported. Applicability to both solution- and solid-phase chemistry has been demonstrated for a variety of amines and carboxylic acids.
The electronic effects of tetranuclear zinc cluster catalysts on transesterification were investigated by changing the carboxylate ligands in the clusters. High catalyst activity crucially depended on the balance between Lewis acidity and Brønsted basicity of the catalyst; this was consistent with the dual activation of both the electrophile and nucleophile by the cooperative zinc centers. In addition