demonstrated broad substrate scope and good compatibility of functional groups. 2-Aryl benzothiazole and 2-aryl benzoimidazole could be smoothly assembled in the same manner. On the basis of preliminary mechanisticstudies, base initiated and aromatization driven β-carbon elimination was considered to be the key step for the formation of 2. This reaction offers an alternative, facile, and sustainable route to
Synthesis of benzoxazoles <i>via</i> the copper-catalyzed hydroamination of alkynones with 2-aminophenols
作者:Kohei Oshimoto、Hiroaki Tsuji、Motoi Kawatsura
DOI:10.1039/c9ob00572b
日期:——
describe herein the synthetic method to benzoxazole derivatives via the copper-catalyzed hydroamination of alkynones with 2-aminophenols. The method produced a wide variety of functionalized benzoxazole derivatives in good yields. Preliminary mechanistic experiments revealed that the reaction would proceed through the copper-catalyzed hydroamination of alkynones and the sequential intramolecular cyclization
Iodine Promoted One-Pot Synthesis of 2-Aryl Benzoxazoles from Amidoximes via Oxidative Cyclization and Ring Contraction
作者:Yong Zhang、Min Ji
DOI:10.1002/ejoc.201901468
日期:2019.12.8
An I2‐promoted sequential oxidative cyclization and ringcontraction reaction is developed for the synthesis of 2‐aryl benzoxazoles by using amidoximes rather than the limited 2‐aminophenols or 2‐haloamides as substrates. This method provides a potential route for introducing certain groups at any site of the 2‐aryl benzoxazole scaffold.
An acid-mediated selective cleavage of C–C doublebond of N-(2-hydroxylphenyl)enaminones with formation a new C–O bond for the synthesis of 2-substituted benzoxazoles has been developed. This protocol proceeds under transition metal- and oxidant-free conditions with broad functional group tolerance. The oxidative cleavage of C–C doublebond of N-(2-hydroxylphenyl)enaminone is also realized using NCS