CuI-Catalyzed Amination of Arylhalides with Guanidines or Amidines: A Facile Synthesis of 1-<i>H</i>-2-Substituted Benzimidazoles
作者:Xiaohu Deng、Heather McAllister、Neelakandha S. Mani
DOI:10.1021/jo900912h
日期:2009.8.7
CuI/L5 (N,N′-dimethylethylenediamine) proves to be an efficient catalyst system for the amination of arylhalides with guanidines. The same catalyst system is then successfully applied to the one-step synthesis of 1-H-2-amino-benzimidazoles through tandem aminations of 1,2-dihaloarenes in modest yields. This methodology is also applicable for the preparation of 1-H or 1-substutituted 2-aryl- or 2-alkyl-benzimidazoles
事实证明,CuI / L5(N,N'-二甲基乙二胺)是一种用于将芳基卤化物与胍胺化的有效催化剂体系。然后将相同的催化剂体系成功地通过1,2-二卤代芳烃的串联胺化以适度的产率成功地一步合成1- H -2-氨基-苯并咪唑。该方法学也可用于制备1- H或1-取代的2-芳基-或2-烷基-苯并咪唑。
Synthesis of annulated benzimidazoles via amidine cyclization
Structurally diverse annulated benzimidazoles were synthesized via two copper(I)-catalyzed cyclocondensation reactions. In the first case the title compounds were prepared from lactams and o-bromoaniline. An alternative route consisted of an intramolecular cyclization of o-bromoarylamidines.
Barton esters for initiator-free radical cyclisation with heteroaromatic substitution
作者:Robert Coyle、Karen Fahey、Fawaz Aldabbagh
DOI:10.1039/c3ob27313j
日期:——
first examples of efficientradicalcyclisation with (hetero)aromatic substitution via Barton ester intermediates. Cyclopropyl and alkyl radicals allow access to five, six and seven-membered alicyclic-ring fused heterocycles with and without an additional fused cyclopropane, including the skeleton of the anti-cancer agent, cyclopropamitosene, expanded, and diazole analogues. Radical initiators are not
There is provided a compound of the formula (I′):
wherein x is a nitrogen or CRx, Rx is a hydrogen, etc., R
1
is an optionally substituted hydrocarbon group, etc., R
2
is an optionally substituted hydrocarbon group, etc., ring A is 5- to 8-membered heterocyclic ring, etc., and each of Y
1
, Y
2
and Y
3
is an optionally substituted carbon or a nitrogen, etc.; or a salt thereof or a prodrug thereof, which have CRF receptor antagonistic activity and use thereof.
Metal-Free Sequential C(sp<sup>2</sup>)–H/OH and C(sp<sup>3</sup>)–H Aminations of Nitrosoarenes and <i>N</i>-Heterocycles to Ring-Fused Imidazoles
作者:Anisha Purkait、Subhra Kanti Roy、Hemant Kumar Srivastava、Chandan K. Jana
DOI:10.1021/acs.orglett.7b00832
日期:2017.5.19
Hydrogen bond assisted ortho-selective C(sp2)–Hamination of nitrosoarenes and subsequent α-C(sp3)-H functionalization of aliphatic amines is achieved under metal-free conditions. The annulation of nitrosoarenes and 2-hydroxy-C-nitroso compounds with N-heterocycles provides a facile excess to a wide range of biologically relevant ring-fused benzimidazoles and structurally novel polycyclic imidazoles
氢键辅助的亚硝基芳烃的邻位选择性C(sp 2)-H氨基化和随后的α-C(sp 3)-H脂肪族胺的官能化在无金属条件下实现。亚硝基芳烃和2-羟基-C-亚硝基化合物与N-杂环的环化分别提供了相对于广泛的生物学相关的环稠合的苯并咪唑和结构上新颖的多环咪唑的简便过量。发现在卤代亚硝基芳烃的C(sp 2)–H胺化过程中,亲核芳香族氢取代(S N ArH)比经典S N Ar反应更可取。