MAOS ofD‐Gluconic Acid,D‐Glucono‐1,4‐ and 1,5‐Lactones, Esters, Hydrazides, and Benzimidazoles Thereof
摘要:
Microwave-assisted organic synthesis (MAOS) of D-gluconic acid can be efficiently done by oxidation of D- glucose with bromine water, upon irradiation with microwave ( MW). It was also used for the conversion of D-gluconic acid to ethyl D-gluconate, D-glucono-1,4- and 1,5-lactones, gluconyl hydrazide, and gluconyl phenylhydrazide in yields comparable to those obtained by conventional methods, but in much shorter times. A convenient microwave- mediated condensation of D- gluconic acid with o-phenylenediamines provided the respective acyclonucleoside benzimidazole in short time and good yield.[GRAPHICS]
Using Molecular Iodine in Direct Oxidative Condensation of Aldoses with Diamines: An Improved Synthesis of Aldo-benzimidazoles and Aldo-naphthimidazoles for Carbohydrate Analysis
practical method has been developed for conversion of unprotected and unmodified aldoses to aldo-benzimidazoles and aldo-naphthimidazoles. Using iodine as an oxidant or promoter in acetic acid solution, a series of mono-, di-, and trialdoses, including those containing carboxyl and acetamido groups, undergo an oxidative condensation reaction with o-phenylenediamine or 2,3-naphthalenediamine at room
Asymmetric induction in addition of N-nitrenes to alkenes: 2-(chiral)substituted benzimidazole-derived N-nitrene additions to alkenes
作者:Robert S. Atkinson、Gary Tughan
DOI:10.1039/p19870002787
日期:——
Oxidation of the optically active 1-aminobenzimidazoles (5)–(7) with lead tetra-acetate in the presence of various prochiral alkenes yields mixtures of the diastereoisomeric aziridines with little asymmetricinduction (Table). Oxidation of theracemic 1-amino-2-(1,2,2-trimethylpropyl)-1H-benzimidazole (12) in the presence of α-methylene-γ-butyrolactone (1) yields the stereoisomeric azirid (16) in a
Moore; Link, Journal of Biological Chemistry, 1940, vol. 133, p. 293,304
作者:Moore、Link
DOI:——
日期:——
Photocatalysis by 3,6-Disubstituted-<i>s</i>-Tetrazine: Visible-Light Driven Metal-Free Green Synthesis of 2-Substituted Benzimidazole and Benzothiazole
作者:Suvendu Samanta、Sudipto Das、Papu Biswas
DOI:10.1021/jo401445j
日期:2013.11.15
s-Tetrazine based molecules were prepared for visible-light-driven organic transformations. The 3,6-di(pyridin-2-yl)-1,2,4,5-tetrazine (pytz) derivative shows visible light absorption and reversible one-electron reduction behavior. In the presence of pytz and aerial oxygen, aldehyde reacts with o-phenylenediamine or o-aminothiophenol under visible light irradiation at ambient temperature to produce corresponding 2-substituted benzimidazoles and benzothiazoles, respectively. Pytz catalyst demonstrates excellent catalytic activity for alkyl, aryl, organo-metallic substituted aldehydes and reducing sugar. The reaction yield is high for both the electron-donating and electron withdrawing substituents in aromatic aldehydes. The use of a metal-free catalyst and visible light energy, along with the mild reaction conditions, makes this reaction an environmentally benign and energy-saving chemical process.
Griess; Harrow, Chemische Berichte, 1887, vol. 20, p. 2207