Efficient and Controllably Selective Preparation of Esters Using Uronium-Based Coupling Agents
摘要:
Carboxylic acid esters can be prepared in excellent yields at room temperature from an acid and either a phenol or an aliphatic alcohol using Me peptide coupling reagents, TBTU, TATU, or COMU, in the presence of organic bases. Reactions using TBTU and TATU are faster but do not occur with tertiary alcohols. Selectivity between reaction with primary or secondary alcohols in diols and polyols can be achieved with choice of base and coupling agent.
A polyester composition with gas barrier properties, including polyester polymerized by glycol and dicarboxylic acid, gas barrier enhancing additives, and antioxidants, wherein the gas barrier enhancing additive includes compounds with following chemical formula: