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 earthmetal 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
Bismuth Oxide Perchlorate as a Highly Efficient Catalyst for Heteroatom Acylation Under Solvent-Free Conditions
作者:Asit K. Chakraborti、Rajesh Gulhane、Shivani
DOI:10.1055/s-2003-41442
日期:——
Bismuth oxide perchlorate efficiently catalyzes the acetylation of structurally diverse phenols, alcohols, thiols, and amines undersolventfree conditions. Sterically hindered and electron deficient phenols are acetylated in excellent yields with stoichiometric amounts of Ac 2 O at room temperature. Acylation of acid-sensitive alcohols is carried out efficiently without competitive side reactions
高氯酸铋在无溶剂条件下有效催化结构不同的酚、醇、硫醇和胺的乙酰化。空间位阻和缺电子酚在室温下用化学计量的 Ac 2 O 以极好的收率乙酰化。酸敏感醇的酰化可以有效地进行,没有竞争性副反应。光学活性底物被乙酰化,对光学纯度没有任何不利影响。