Electrostatic catalysis by ionic aggregates: scope and limitations of Mg(ClO4)2 as acylation catalyst
作者:Asit K Chakraborti、Lalima Sharma、Rajesh Gulhane、Shivani
DOI:10.1016/j.tet.2003.08.007
日期:2003.9
Alkali and alkaline earth metal perchlorates exhibit electrostatic catalysis in the activation of anhydrides for the acylation reaction. Perchlorates with higher values of the charge-size function of the metal ion exhibit better catalytic activity following the order Mg(ClO4)2>Ba(ClO4)2>LiClO4. Acylation of structurally diverse phenols, thiols, alcohols, and amines have been carried out with stoichiometric
碱和碱土金属高氯酸盐在酸酐活化过程中表现出静电催化作用,可进行酰化反应。金属离子的电荷大小函数的值较高的高氯酸盐表现出更好的催化活性,遵循Mg(ClO 4)2 > Ba(ClO 4)2 > LiClO 4的顺序。在室温下,在无溶剂条件下,在催化量的Mg(ClO 4)2存在下,用化学计量的酸酐对结构多样的酚,硫醇,醇和胺进行酰化反应。受阻和电子不足的酚可被有效地酰化。与空间受阻的酸酐(如异丁酸,新戊酸和苯甲酸酐)的酰化反应可与苯酚和醇类以极高的收率进行。酸敏感的醇以极好的收率被酰化,而没有任何竞争性副反应。