Rh(III)‐Catalyzed Intramolecular Oxidative Annulation of Propargyl Amino Phenyl Benzamides to Access Pyrido/ Isoquinolino Quinoxalinones
作者:Gurram Ravi Kumar、Ravi Kumar、Manda Rajesh、B. Sridhar、Maddi Sridhar Reddy
DOI:10.1002/adsc.201900772
日期:2019.10.22
A rhodium catalyzed copper mediated double oxidativeannulation of propargylamino phenylbenzamides is developed. A quick assembly of tri, tetra and penta cyclic pyrido/isoquinolo‐quinoxilines are thus achieved from readily available linear substrates. The reaction is shown to be very general by accommodating a large variety of substrates in the transformation. A mechanism through an amide directed
developed one‐step protocols for the preparation of a large selection of α‐aminocyclopropyl ketones or benzo[d]imidazoles, by reacting 2‐substituted‐2‐hydroxycyclobutanones with aryl amines or o‐phenylenediamines, respectively. In most case the reactions proceed at room temperature and are catalyst‐free. The formation of benzo[d]imidazoles is rationalized in terms of an unusual ring‐closure/ring‐fission process
Diversity Oriented Synthesis of Indoloazepinobenzimidazole and Benzimidazotriazolobenzodiazepine from<i>N</i><sup>1</sup>-Alkyne-1,2-diamines
作者:Ravi Kumar、Rajesh K. Arigela、Srinivas Samala、Bijoy Kundu
DOI:10.1002/chem.201502956
日期:2015.12.14
oriented synthesis of two N‐polyheterocycles indoloazepinobenzimidazole and benzimidazotriazolobenzodiazepine from a common N1‐alkyne‐1,2‐diamine building block is described. The approach involves sequential formation of benzimidazole through cyclocondensation and oxidation, which is followed by the formation of either an azepine ring (through alkyne activation and 6‐endo‐dig cyclization, 1,2‐migration
d-Glucose has been identified as an efficient C1 synthon in the synthesis of benzimidazoles from o-phenylenediamines via an oxidative cyclization strategy. Isotopic studies with 13C6-d-glucose and D2O unambiguously confirmed the source of methine. The notable features of this method include the following: broad functional group tolerance, a biorenewable methine source, excellent reaction yields, a
d-葡萄糖已被确定为通过氧化环化策略由邻苯二胺合成苯并咪唑的有效C1合成子。用13 C 6 - d-葡萄糖和D 2 O进行的同位素研究明确证实了次甲基的来源。该方法的显着特征包括:宽泛的官能团耐受性,可生物再生的次甲基来源,优异的反应收率,较短的反应时间,水作为环境友好的溶剂以及以克为单位的维生素B 12组分的合成。
“All-water” one-pot diverse synthesis of 1,2-disubstituted benzimidazoles: hydrogen bond driven ‘synergistic electrophile–nucleophile dual activation’ by water
作者:Damodara N. Kommi、Pradeep S. Jadhavar、Dinesh Kumar、Asit K. Chakraborti
DOI:10.1039/c3gc37004f
日期:——
promoting the subsequent nitro reduction and in the final cyclocondensation steps. The role of water in promoting the cyclocondensation reaction through hydrogen bonds is realized by the differential product yields during the reaction of mono-N-phenyl-o-phenylenediamine with benzaldehyde performed separately in water and D2O. The better hydrogen bond donor and hydrogen bond acceptor abilities of water