四烃基二锡氧烷在酯化反应中的催化作用

Studies on Tetraorganodistannoxane-catalyzed Esterification

1,1,3,3-四烃基二锡氧烷Ⅰ是一类有机锡氧簇合物, 它在固相和液相中[1,2]均为二聚梯形层状结构, 在有机合成中表现出特殊的催化活性, 与其它含Sn-O键非簇类化合物相比, 催化活性和选择性均有大幅度提高. 该类化合物是酯交换、酯化、官能团保护和脱保护等反应的优良催化剂[3]. 本文合成了一系列四烃基二锡氧烷, 并以乙酸与丁醇的酯化反应为例, 研究其对该反应的催化作用.

Abstract 1,1,3,3-Tetraorganodistannoxanes are a sort of organotinoxo clusters. They show an excellentcatalytic activity in organic synthesis because they have unique dimeric ladder structures that contain twokinds of five-coordinated tin atoms. Despite of involving a metalloxane core, the distannoxane is quite solu-ble in organic solvents. This is attributable to the double-layered structure of the distannoxanes in whichthe surface alkyl groups prevent the inorganic core from being exposed to the solvent phase. In this articletetraorganodistannoxane-catalyzed esterification of acetic acid and w-butanol was studied. Various cata-lysts , different proportions of acid and alcohol and dosages of catalysts affected this reaction. The mecha-nism of tetraorganodistannoxane-catalyzed esterification is also discussed.