Potassium Hydroxide/Dimethyl Sulfoxide Promoted Intramolecular Cyclization for the Synthesis of Benzimidazol-2-ones
摘要:
A new protocol for intramolecular N-arylations of ureas to form benzimidazol-2-ones has been developed. The cyclization reaction occurs In the presence of KOH and DMSO at close to ambient temperature. Under these conditions the yields are high and a wide range of functional groups are tolerated.
Pd(II)/Ag(I)-Promoted One-Pot Synthesis of Cyclic Ureas from (Hetero)Aromatic Amines and Isocyanates
作者:So Won Youn、Yi Hyun Kim
DOI:10.1021/acs.orglett.6b03151
日期:2016.12.2
A simple and facile one-pot reaction has been developed to afford a diverse range of N,N′-disubstituted benzimidazolones and imidazopyridinones containing two differently substituted N atoms. A cooperative Pd(II)/Ag(I) system promotes the sequential addition/intramolecular C–H amidationreaction of (hetero)aromatic amines and isocyanates, leading to the formation of two C–N bonds. A mechanism involving
已经开发出一种简单且容易的一锅反应,以提供包含两个不同取代的N原子的N,N'-二取代的苯并咪唑酮和咪唑并吡啶并酮的不同范围。协同的Pd(II)/ Ag(I)系统促进了(杂)芳族胺和异氰酸酯的顺序加成/分子内CH-H酰胺化反应,导致形成两个C-N键。一种机制,涉及在Ag 2 CO 3氧化剂和Pd(OAc)2存在下通过单电子转移(SET)生成的自由基中间体提出了路易斯酸。该协议使用易于获得的起始原料,良好的官能团耐受性和高效率,提供了一种操作简便,简单且可靠的方法。
Metal-Free Oxidative C-H Amidation of<i>N</i>,<i>N′</i>-Diarylureas with PhI(OAc)<sub>2</sub>: Synthesis of Benzimidazol-2-one Derivatives
作者:Jipan Yu、Chang Gao、Zhixuan Song、Haijun Yang、Hua Fu
DOI:10.1002/ejoc.201500726
日期:2015.9
compounds or intramolecular N-arylations using substrates with carbon-halogen bonds. However, the starting materials of these protocols are often not readily available. Herein, a simple and practical metal-free oxidative C–H amidation of N,N′-diarylureas has been developed that takes place at room temperature. This protocol uses readily available N,N′-diarylureas as the starting materials and inexpensive
Potassiumhydroxide (KOH) in dimethylsulfoxide (DMSO) forms a superbasic medium that allows one to access cross-coupling products from reactions between aryl halides with various sulfur-, oxygen- and nitrogen-based nucleophiles undertransitionmetal-free conditions.
Potassium Hydroxide/Dimethyl Sulfoxide Promoted Intramolecular Cyclization for the Synthesis of Benzimidazol-2-ones
作者:Astrid Beyer、Christine M. M. Reucher、Carsten Bolm
DOI:10.1021/ol2008878
日期:2011.6.3
A new protocol for intramolecular N-arylations of ureas to form benzimidazol-2-ones has been developed. The cyclization reaction occurs In the presence of KOH and DMSO at close to ambient temperature. Under these conditions the yields are high and a wide range of functional groups are tolerated.