Cyanide as a Powerful Catalyst for Facile Preparation of 2-Substituted Benzoxazoles<i>via</i>Aerobic Oxidation
作者:Yeon Ho Cho、Chun-Young Lee、Deok-Chan Ha、Cheol-Hong Cheon
DOI:10.1002/adsc.201200684
日期:2012.11.12
synthesis of 2-substituted benzoxazoles from Schiff bases via aerobic oxidation has been developed. The products from various Schiff bases were obtained in high yields in an open flask under ambient conditions without other external oxidants. We have also developed a simple one-step protocol for the synthesis of benzoxazoles from aminophenol and the corresponding aldehydes in the presence of cyanide without
Dess-Martin Periodinane Mediated Intramolecular Cyclization of Phenolic Azomethines: A Solution-Phase Strategy toward Benzoxazoles and Benzothiazoles
作者:D. Bose、Mohd. Idrees
DOI:10.1055/s-0029-1217136
日期:2010.2
Dess-Martin periodinane (DMP), a highly versatile hypervalent iodine(V) reagent, was found to efficiently mediate the intramolecular cyclization of phenolic azomethines/Schiff bases at ambient temperature leading to the rapid and expeditious synthesis of substituted benzoxazoles and benzothiazoles. Furthermore, a solution-phase strategy has been developed by treating the reaction mixtures sequentially with Amberlyst A-26 thiosulfate resin and diisopropylaminomethyl resin (PS-DIEA), which remove excess reagent and byproducts, to give pure products.
Cyanide as a powerful catalyst for facile synthesis of benzofused heteroaromatic compounds via aerobic oxidation
作者:Yeon-Ho Cho、Chun-Young Lee、Cheol-Hong Cheon
DOI:10.1016/j.tet.2013.05.138
日期:2013.8
Highly efficientsynthesis of benzofused heteroaromatic compounds via aerobicoxidationcatalyzed by cyanide anion has been developed. The Schiff bases derived from 2-aminophenol and aldehydes provided the corresponding benzoxazoles in high yields in the presence of a catalytic amount of cyanide in an open flask under ambient conditions without the use of any external metal co-oxidants and bases. Furthermore