Synthesis of N-(4-arylmethylene-Δ<sup>2</sup>-oxazolin-5-ylidene)ammonium salts and their conversion into 5-imino-Δ<sup>2</sup>-oxazolines and 1,3-diazafulvenes
作者:G. V. Boyd、P. H. Wright
DOI:10.1039/p19720001140
日期:——
secondary or tertiary amides of α-benzamidocinnamic acids with acetic anhydride–perchloric acid gave N-(4-arylmethylene-2-phenyl-Δ2-oxazolin-5-ylidene)ammonium perchlorates. The N-monosubstituted iminium salts were deprotonated to yield the corresponding 4-arylmethylene-5-imino-Δ2-oxazolines; successive treatment of two NN-disubstituted iminium perchlorates with ammonia and sodium hydroxide produced novel
A concise approach to polysubstituted oxazoles from N-acyl-2-bromo enamides via a copper(<scp>i</scp>)/amino acid-catalyzed intramolecular C–O bond formation
intramolecular Ullmann-type C–O coupling reaction has been developed. This protocol affords a facile methodology for the synthesis of a series of novel 2,4,5-substituted oxazoles from readily accessible N-acyl-2-bromo enamides under mild conditions.