Visible light promoted tandem dehydrogenation-deaminative cyclocondensation under aerobic conditions for the synthesis of 2-aryl benzimidazoles/quinoxalines from <i>ortho</i>-phenylenediamines and arylmethyl/ethyl amines
作者:Firdoos Ahmad Sofi、Rohit Sharma、Ravi Rawat、Asit K. Chakraborti、Prasad V. Bharatam
DOI:10.1039/d0nj03002c
日期:——
Visible light promoted dominosynthesis of 2-aryl benzimidazoles is reported through the reaction of ortho-phenylenediamines and arylmethyl amines underaerobicconditions. The methodology has wide substrate scope and tolerates a wide range of functional groups affording the products in high yields. The use of arylethyl amines instead of arylmethyl amines gives 2-aryl quinoxalines.
Elemental sulfur mediated synthesis of benzoxazoles, benzothiazoles and quinoxalines via decarboxylative coupling of 2-hydroxy/mercapto/amino-anilines with cinnamic acids
An easy and practical method has been developed for the synthesis of 2-benzylbenzoxazoles and 2-benzylbenzothiazoles using sulfur mediated decarboxylativecoupling of cinnamic acids with 2-hydroxyanilines and 2-mercaptoanilines respectively under metal- and solvent-free conditions. However, the reaction of 2-aminoanilines with cinnamic acids leads to the formation of 2-arylquinoxalines under the same
Multifold Bond Cleavage and Formation between MeOH and Quinoxalines (or Benzothiazoles): Synthesis of Carbaldehyde Dimethyl Acetals
作者:Yunkui Liu、Bo Jiang、Wei Zhang、Zhenyuan Xu
DOI:10.1021/jo302450f
日期:2013.2.1
2-quinoxalinyl (or 2-benzothiazolyl) carbaldehyde dimethyl acetals has been achieved. 2-Quinoxalinyl carbaldehyde dimethyl acetals were readily converted into 2-quinoxalinyl carbaldehydes in good to excellent yields under acidic conditions. Preliminary mechanistic studies suggest that the reaction proceeds via multifold bond cleavage and formation between methanol and N-heterocycles involving a dioxygen-participated
已经实现了由AK 2 S 2 O 8介导的喹喔啉(或苯并噻唑)与甲醇的直接交叉偶联反应,从而生成了2-喹喔啉基(或2-苯并噻唑基)甲醛二甲基乙缩醛。在酸性条件下,2-喹喔啉基甲醛二甲基乙缩醛易于以良好或优异的收率转化成2-喹喔啉基甲醛。初步的机理研究表明,该反应是通过多重键裂解和甲醇与N-杂环之间的形成而进行的,涉及双氧参与的自由基过程。该方法可以通过简单的N的交叉偶联直接合成各种2-喹喔啉基(或2-苯并噻唑基)甲醛二甲基乙缩醛。-在无醛,无酸和无过渡金属的条件下,杂环C–H键和甲醇。
Oxidative Synthesis of Benzimidazoles, Quinoxalines, and Benzoxazoles from Primary Amines by <i>ortho</i>-Quinone Catalysis
作者:Ruipu Zhang、Yan Qin、Long Zhang、Sanzhong Luo
DOI:10.1021/acs.orglett.7b02786
日期:2017.10.20
The bioinspired ortho-quinone catalysts have been applied to heterocycles synthesis. Without any metal cocatalysts, a sole ortho-quinone catalyst enables the oxidative synthesis of benzimidazoles, quinoxalines and benzoxazoles from primary amines in high yields under mild conditions with oxygen as the terminal oxidant.
General Asymmetric Hydrogenation of 2-Alkyl- and 2-Aryl-Substituted Quinoxaline Derivatives Catalyzed by Iridium-Difluorphos: Unusual Halide Effect and Synthetic Application
A general asymmetric hydrogenation of a wide range of 2-alkyl- and 2-aryl-substituted quinoxaline derivatives catalyzed by an iridium–difluorphos complex has been developed. Under mild reaction conditions, the corresponding biologically relevant 2-substituted-1,2,3,4-tetrahydroquinoxaline units were obtained in high yields and good to excellent enantioselectivities up to 95%. With a catalyst ratio
已开发出由铱-二氟配合物催化的各种2-烷基和2-芳基取代的喹喔啉衍生物的一般不对称氢化反应。在温和的反应条件下,可以以高收率和高达95%的良好至优异的对映选择性获得相应的生物学上相关的2-取代-1,2,3,4-四氢喹喔啉单元。催化剂比为S / C = 1000且以克为单位,Ir-二氟膦配合物的催化活性得以保持,并显示出其潜在价值。最后,我们证明了我们的方法在化合物(S)-9的合成中的应用,该化合物是胆固醇酯转移蛋白(CETP)的抑制剂。