inexpensive NH4SCN has been developed using carbonnitride (g-C3N4) as a general heterogeneous catalyst in a greensolvent under an air atmosphere and the irradiation of a blue LED. Various thiocyanated heterocycles including indolo[2,1-a]isoquinolin-6(5H)-ones, benzimidazo[2,1-a]isoquinolin-6(5H)-ones, thioflavones, azaspiro[4.5]trienones and imidazo[1,2-a]pyridines were successfully synthesized in good
已经开发了一种无金属的光催化策略,用于在廉价的NH 4 SCN中以氮化碳(gC 3 N 4)作为绿色溶剂中的普通多相催化剂,在空气气氛下和蓝色LED的照射下制备硫氰化杂环。各种硫氰酸盐杂环,包括吲哚[2,1- a ]异喹啉-6(5 H)-one,苯并咪唑并[2,1- a ]异喹啉-6(5 H)-one,硫代黄酮,氮杂螺[4.5]三烯酮和咪唑[ 1,2-一以高产率(高达96%)成功合成了]吡啶。重要的是,这种无金属和无外部氧化剂的方法使用碳酸二甲酯作为绿色介质,避免了传统的挥发性有机溶剂。此外,可循环使用的gC 3 N 4催化剂可使用至少8次,而不会显着降低活性。
Rh-Catalyzed oxidative C–H activation/annulation: converting anilines to indoles using molecular oxygen as the sole oxidant
作者:Guoying Zhang、Hui Yu、Guiping Qin、Hanmin Huang
DOI:10.1039/c3cc49751h
日期:——
A practical and efficient Rh(III)-catalyzed aerobic C-Hactivation has been developed for the facile synthesis of a broad range of indoles from simple anilines and alkynes. The protocol could be conducted under mild conditions and used environmentally friendly oxygen as the sole clear oxidant.
<i>Syn</i>-<i>versus anti</i>-carbopalladation of alkynes with organoborons: access to indoles symmetrically and unsymmetrically substituted on their 2,3-positions
A palladium (II)-catalyzed borono-ortho-CH activation/amination cascade for the construction of two C–N bonds and one C–C bond in a single synthetic sequence is reported. This method proceeds through a formal syn-carbopalladation of alkynes with organoboron compounds, forming alkenyl palladium species, which are trapped by simple amines to provide highly substituted indoles. Remarkably, with an electron-rich