A Gold‐Catalyzed Acid‐Assisted Regioselective Cyclization for the Synthesis of Polysubstituted Oxazoles
作者:Qian Wang、Stephanie Hoffmann、Jasmin Schießl、Matthias Rudolph、Frank Rominger、A. Stephen K. Hashmi
DOI:10.1002/ejoc.201900699
日期:2020.5.3
derivatives are obtained through a regioselective gold‐catalyzed reaction of α‐alkynylamides and alkynoates in the presence of nitriles. The intermediary obtained gold carbenes are generated by an alkyne oxidation with a pyridine N‐oxide. Acidic conditions ensure that only one of the two carbonyl oxygen atoms in these intermediates selectively cyclizes to the products in excellent yields.
Direct Synthesis of 2,5-Disubstituted Oxazoles through an Iodine-Catalyzed Decarboxylative Domino Reaction
作者:Wei Xu、Ulrich Kloeckner、Boris J. Nachtsheim
DOI:10.1021/jo400753n
日期:2013.6.21
An efficient iodine-catalyzed synthesis of highly substituted oxazoles is presented. Starting from readily available aryl methylketones, β-keto esters, or styrenes, in combination with α-amino acids as amine-containing coupling partners, the corresponding 2-alkyl-5-aryl- substituted oxazoles were obtained in up to 80% yield via a decarboxylative domino reaction.