Silica supported tungstic acid (STA): an efficient catalyst for the synthesis of bis-spiro piperidine derivatives under milder condition
作者:Amol B. Atar、Yeon Tae Jeong
DOI:10.1016/j.tetlet.2012.12.105
日期:2013.3
A mild, efficient, and expeditious method has been developed for the synthesis of 3,5-dispirosubstituted piperidines via a threecomponent, one-pot cyclocondensation reaction of aromatic amines, formaldehyde, and dimedone using Silica supported tungstic acid as heterogeneous catalyst for the first time. The reaction involving formation of six new covalent bonds was conveniently promoted by Silica supported
An efficient pseudo six-component synthesis of bis-spiropiperidines is described by one-pot condensation of formaldehyde, aromaticamine and dimedone or N,N-dimethyl-barbituric acid using nano-CuFe2O4@chitosan at room temperature. This method provides several advantages including mild reaction conditions, applicability to wide range of substrates, reusability of the catalyst and little catalyst loading