Synthesis of 2,4,5-Trisubstituted Oxazoles via Pd-Catalyzed C–H Addition to Nitriles/Cyclization Sequences
作者:Di Zhang、Hao Song、Na Cheng、Wei-Wei Liao
DOI:10.1021/acs.orglett.9b00700
日期:2019.4.19
A practical and flexible intermolecular protocol for the diverse synthesis of trisubstituted oxazole derivatives via a Pd-catalyzed direct C–H addition of electronic-rich heteroarenes to O-acyl cyanohydrins bearing an α-hydrogen/cyclization sequence is described. A wide range of trisubstituted oxazoles can be prepared from readily available starting materials in good to high yields with high efficiency
Highly regioselective synthesis of 2,4,5-(hetero)aryl substituted oxazoles by intermolecular [3+2]-cycloaddition of unsymmetrical internal alkynes
作者:Elli Chatzopoulou、Paul W. Davies
DOI:10.1039/c3cc45410j
日期:——
A robust N-nucleophilic 1,3-N,O-dipole equivalent reacts with unsymmetrical internal alkynes under gold catalysis. Conjugation from a remote nitrogen lone pair enables and controls this convergent and highly regioselective process.