Cu-Catalyzed Oxidative Amidation of Propiolic Acids Under Air via Decarboxylative Coupling
作者:Wei Jia、Ning Jiao
DOI:10.1021/ol1004615
日期:2010.5.7
A Cu-catalyzed aerobic oxidative amidation of propiolicacids via decarboxylation under air has been developed. Only carbon dioxide is produced as byproduct in this approach. The use of air as oxidant makes this method more useful and easy to handle.
Phosphane-Free Copper-Catalyzed Decarboxylative Coupling of Alkynyl Carboxylic Acids with Aryl Halides under Aerobic Conditions
作者:Delin Pan、Chun Zhang、Shengtao Ding、Ning Jiao
DOI:10.1002/ejoc.201100659
日期:2011.7.18
A phosphane-free copper-catalyzed decarboxylativecross-coupling reaction of alkynyl carboxylicacids with aryl halides was developed. CuBr (1–5 mol-%) was used as a catalyst in the presence of a β-diketone ligand in air. The reactions of aryliodides were conducted in the absence of a Pd catalyst. The ligand plays a key role in this kind of copper catalysis. NaNO2 was disclosed to efficiently improve
Diazo Tetramic Acids Provide Access to Natural-Like Spirocyclic Δ<sup>α,β</sup>-Butenolides through Rh(II)-Catalyzed O–H Insertion/Base-Promoted Cyclization
3-Diazotetramic acids were found to be valid substrates for the recently discovered approach toward natural-like Δα,β-spirobutenolides via Rh(II)-catalyzed O–H insertion into propiolicacids followed by base-promoted intramolecular Michael addition. The target Δα,β-spirobutenolides were obtained in generally high yields and, in the case of chiral 5-monosubstituted 3-diazotetramic acids, high diastereoselectivity