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。
Functionalized Orthoesters as Powerful Building Blocks for the Efficient Preparation of Heteroaromatic Bicycles
作者:Gulluzar Bastug、Christophe Eviolitte、István E. Markó
DOI:10.1021/ol301472a
日期:2012.7.6
By combining substituted anilines with functionalized orthoesters, an efficient and connective methodology for the preparation of benzoxazole, benzothiazole, and benzimidazole derivatives has been established. The versatility of this approach enables the development of new libraries of heterocycles containing multifunctional sites.
The invention relates to a new class of pyrrolobenzimidazole, benzimidazoloisoquinoline and dipyrodinobenzodiimidazole in cyanine sensitizing dyes derived therefrom and their use in silver halide emulsions, and to methods for preparation of such new dyes.
efficient copper-catalyzedsynthesis of (annelated) benzimidazoles is reported. This transformation is based on a simple and straightforward one-pot sequence involving a copper-catalyzed cross coupling between o-haloanilines and lactams/amides followed by a subsequent cyclization under acidic conditions. A variety of (annelated) benzimidazoles could be easily obtained in high yields from readily available