Synthesis of Benzimidazoles by PIDA-Promoted Direct C(sp<sup>2</sup>)H Imidation of<i>N</i>-Arylamidines
作者:Jinbo Huang、Yimiao He、Yong Wang、Qiang Zhu
DOI:10.1002/chem.201202271
日期:2012.10.29
A metal‐free synthesis of diversified benzimidazoles from N‐arylamidines through a phenyliodine(III) diacetate (PIDA) promoted intramolecular direct C(sp2)H imidation has been developed. The reaction proceeds smoothly at 0 °C or ambient temperature to provide the desired products in good to excellent yields. The synthesis of 2‐alkyl‐ or 2‐alkyl‐fused benzimidazoles, which are generally inaccessible
Lewis acid-catalyzed 2-arylquinazoline formation from N′-arylbenzimidamides and paraformaldehyde
作者:Xiufang Cheng、Huamin Wang、Fuhong Xiao、Guo-Jun Deng
DOI:10.1039/c6gc02319c
日期:——
An efficient procedure for the synthesis of 2-arylquinazolines from N'-arylbenzimidamides has been developed under transition-metal-free conditions. In this process, stable and low toxicity paraformaldehyde was used as the carbon source....
Construction of 1,2-dihydro-1,3,5-triazines <i>via</i> reactions involving amidines
作者:Honghong Guo、Jianying Lin、Qiang Liu、Xing Li
DOI:10.1039/d3ob00283g
日期:——
synthesized through three sets of reactions of amidines with, respectively, paraformaldehyde, aldehydes and N-arylnitrones under different conditions. The catalysts used in these three reactions were Cu(OAc)2, ZnI2 and CuCl2·2H2O, respectively. Most of the substrates tested for these reactions provided the target products in moderate to good yields. In the reactionsinvolving paraformaldehyde, Cu(OAc)2 also
A general and practicalmethod for the construction of various 3,4,5-trisubstituted 1,2,4-triazoles via I2-catalyzed cycloaddition of N-functionalized amidines with hydrazones is reported. This strategy features cheap and readily available catalyst and starting materials, broader substrate scope, and moderate-to-good yields. The mechanism study shows that the existence of hydrogen on the nitrogen of
报道了一种通过 I 2催化N官能化脒与腙的环加成反应构建各种 3,4,5-三取代 1,2,4-三唑的通用且实用的方法。该策略的特点是廉价且易于获得的催化剂和起始材料、更广泛的底物范围以及中等至良好的产率。机理研究表明,腙氮上氢的存在对于这种转变至关重要。