3-Ethoxycyclobutanones reacted with pyridines, quinolines, and isoquinolines to give the corresponding formal [4+2] cycloadducts, 9a-hydro-2H-quinolizin-2-one derivatives, by using Me3SiOTf in acetonitrile. Cycloaddition of 3-ethoxy-2-monoalkylcyclobutanones to 5-nitroquinoline or 4-cyanopyridine proceeded stereoselectively.
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.
Copper-Catalyzed C–H Azidation of Anilines under Mild Conditions
作者:Conghui Tang、Ning Jiao
DOI:10.1021/ja3089907
日期:2012.11.21
A novel and efficient copper-catalyzed azidation reaction of anilines via C-H activation has been developed. This method, in which the primary amine acts as a directing group by coordinating to the metal center, provides ortho azidation products regioselectively undermildconditions. This effective route for the synthesis of aryl azides is of great significance in view of the versatile reactivity
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.