Lewis-acid Promoted Chemoselective Condensation of 2-Aminobenzimidazoles or 3-Aminoindazoles with 3-Ethoxycyclobutanones to Construct Fused Nitrogen heterocycles
作者:Weiguang Kong、Yao Zhou、Qiuling Song
DOI:10.1002/adsc.201701641
日期:2018.5.16
or 3‐aminoindazoles with 3‐ethoxycyclobutanones is presented. Diverse fused heterocyclesbenzo[4,5]‐imidazo[1,2‐a]pyrimidine and pyrimido[1,2‐b]‐indazole derivatives were obtained in moderate to high yields under mild conditions, the reaction mechanism of which was in sharp contrast to previous [3+3] annulation reaction of 3‐ethoxycyclobutanones.
Lewis Acid-Mediated [3+3] Annulation for the Construction of Substituted Pyrimidine and Pyridine Derivatives
作者:Yao Zhou、Zhonghe Tang、Qiuling Song
DOI:10.1002/adsc.201601386
日期:2017.3.20
A direct and single‐step procedure towards substituted pyrimidine and pyridine derivatives via Lewis acid‐promoted [3+3] annulation between 3‐ethoxycyclobutanones and enamines or amidines is presented. Diverse substituted pyrimidine and pyridine derivatives were obtained in good to high yields with a wide substrate scope.
A Co-catalyzed highly chemo- and regio-selective nitration of C(sp3)-H was developed. Diverse aliphaticnitrocompounds were obtained in good yields, using t-BuONO as nitrating reagent. Specific nitration of C(sp3)-H instead of C(sp2)-H was achieved via a radical process rather than concerted metalation-deprotonation.
Formal [4+4] cycloaddition reactions of 3-ethoxycyclobutanones and 2-silyloxy-1.3-butadienes were catalyzed with EtAlCl2 to afford eight-membered carbocyclic compounds. Steric hindrance of the silyl group of dienes influenced the reaction course for [4+4] or [4+2] cycloaddition.
A Facile Synthesis of Substituted 2-Alkylquinolines through [3 + 3] Annulation between 3-Ethoxycyclobutanones and Aromatic Amines at Room Temperature
作者:Gang Shan、Xiuyun Sun、Qian Xia、Yu Rao
DOI:10.1021/ol202334s
日期:2011.11.4
An efficient single-step approach toward the synthesis of 2-alkylquinolines is described. Through a Lewis acid mediated [3 + 3] annulation reaction between 3-ethoxycyclobutanones and aromatic amines, a variety of multisubstituted 2-alkylquinoline derivatives were prepared regioselectively at room temperature.