silver‐catalyzed chemoselective [4+2] annulation of aryl and heteroaryl isocyanides with α‐substituted isocyanoacetamides was developed for the facile and efficient synthesis of 2‐aminoquinolones, naphthyridines, and phenanthrolines. A mechanism for this multistep domino reaction is proposed on the basis of a 13C‐labeling experiment, according to which an unprecedented chemoselective heterodimerization
catalyst-free chemoselective trimerization reaction of readily available isocyanides is described. This domino reaction provides facile access to a wide range of 2-(indol-2-yl)-quinolines and 2-(indol-2-yl)-pyridines in moderate to excellent yields. A “head to head” heterodimerization of two isocyanides is proposed as the key step of this reaction.
Silver-Catalyzed [3+2] Cycloaddition of Azomethine Ylides with Isocyanides for Imidazole Synthesis
作者:Zhongyan Hu、Jinhuan Dong、Xianxiu Xu
DOI:10.1002/adsc.201700447
日期:2017.10.25
silver-catalyzed aerobic oxidative [3+2] cycloaddition of azomethineylides with aryl or heteroaryl isocyanides has been developed. The reaction represents a novel protocol for the efficient and practical synthesis of 1,2-diarylimidazoles bearing a broad range of substituents in good to excellent yields under mild conditions. The practicability of this cycloaddition was shown by a gram-scale synthesis
A convenient preparation of functionalized arylzinc compounds by the reaction of zinc/silver-graphite with aryl iodides
作者:Alois Fürstner、Robert Singer、Paul Knochel
DOI:10.1016/s0040-4039(00)79962-x
日期:1994.2
Aryl- and hetero-aryl iodides react under very mild conditions (THF, 25 °C) with a Zn(Ag) couple deposited on graphite leading to the corresponding zinc reagents in excellent yields. In the presence of CuCN·2LiCl or catalytic amounts of Pd(0), these unsaturated zinc species can be acylated, allylated or coupled with iodoalkenes.
A novel three-component, one-pot reaction between primary (S)-amino acid amides, aldehydes and isocyanides in the presence of acetic acid yielding substituted2-(cyanomethylamino)-acetamides 4 in good yields, is described. First efforts to investigate the mechanism of this reaction were undertaken.