Regioselective cleavage of O-benzyl-N-arylamidoximes: synthesis of N-aryl amidines and amidoximes
摘要:
O-Benzyl-N-arylamidoximes have been regioselectively deprotected to provide either N-aryl amidines or amidoximes. As a result, the targeted compounds can now be prepared using palladium-catalyzed N-arylation chemistry. (C) 2002 Elsevier Science Ltd. All rights reserved.
A new practical carbon-nitrogen bond formation reaction of amidines with ethyl acetoacetate to synthesize imidazoles via oxidative cyclization in the presence of bromide. The reactions were occured under mild and metal-free conditions.
Transition‐Metal‐Free Synthesis of 1,2‐diphenyl‐1
<i>H</i>
‐benzo[
<i>d</i>
] Imidazole Derivatives from
<i>N</i>
‐phenylbenzimidamides and Cyclohexanones
A transition‐metal‐free strategy for the formation of 1,2‐diphenyl‐1H‐benzo[d] imidazoles from N‐phenylbenzimidamides and cyclohexanones is introduced. This is the first report on the direct synthesis of 1,2‐diphenyl‐1H‐benzo[d] imidazoles from cyclohexanones and N‐phenylbenzimidamides via iodine‐ promoted oxidative cyclization. Non‐aromatic cyclohexanones were smoothly dehydrogenated, and acted as
引入了一种无过渡金属的策略,用于由N-苯基苯甲酰胺和环己酮形成1,2-二苯基-1 H-苯并[ d ]咪唑。这是关于通过碘促进的氧化环化反应,由环己酮和N-苯基苯甲酰胺直接合成1,2-二苯基-1 H-苯并[ d ]咪唑的第一份报告。非芳族环己酮可顺利脱氢,并使用氧气作为绿色氧化剂充当芳基源。碘的催化使用使得该方法相当简单,更经济和方便。在优化条件下,各种取代的1,2-二苯基-1 H-苯并[ d使咪唑平稳反应,并以中等至优异的产率生成所需的取代的咪唑。
Reactions of Aryliminodimagnesium with Some<i>N</i>,<i>N</i>-Dimethylcarboxamides and Benzonitriles Affording Various Types of Amidines. Correction of Previous Results on Formamidine Formation from<i>N</i>,<i>N</i>-Dimethylformamide
Some symmetrical and unsymmetrical form- and benzamidines were prepared by the reaction of ArN(MgBr)2 with Ar’CN, HCONMe2 and related compounds in tetrahydrofurn.
A direct method for the synthesis of 1,2,5-triaryl-1H-imidazoles was achieved easily from cyclization of aryl acetaldehydes with amidines catalyzed by I2. Various substitued groups can be employed, and this reaction proceeds smoothly in moderate to good yields.
Iron(III)-catalyzed synthesis of multi-substituted imidazoles via [3+2] cycloaddition reaction of nitroolefins and N-aryl benzamidines
作者:Xiang Liu、Dong Wang、Baohua Chen
DOI:10.1016/j.tet.2013.08.077
日期:2013.11
A novel and efficient iron(III)-catalyzedsynthesis of multi-substituted imidazoles via [3+2] cycloaddition of nitroolefins and N-aryl benzamidines under the air atmosphere had been developed. This methodology is convenient, atom-economical, general, and eco-friendly in good yields and prefect regioselectivities.