Enzyme assisted preparation of enantiomerically pure β-adrenergic blockers I. A facile screening method for suitable biocatalysts
摘要:
The enantioselective preparation of potential precursors for beta-adrenergic blockers was studied by enzymatic hydrolysis of the corresponding ester derivatives. Based on the facile separation of both substrates and products by HPLC on a chiral support a convenient screening method was developed for a rapid evaluation of the best suited esterhydrolase.
乙腈中的氯化钴(II)在温和的条件下催化多种醚与酰基卤的裂解,从而以高收率得到相应的酯。无环脂族醚裂解成相应的酯和氯化物,而环脂族醚产生ω-氯代酯。苄基醚可与苄基氯和苄基乙酰胺一起形成相应的酯。烯丙基和苄基醚裂解的比较研究表明,苄基醚可以在烯丙基醚存在下选择性裂解。可以以高度区域选择性的方式将环氧乙烷酮裂解为相应的β-氯代酯。乙烯基醚经历sp 2在这些条件下的-杂化的碳-氧键裂解。基于产物分析,讨论了涉及电子转移,随后进行O-酰化以及氯离子对S N 1或S N 2的攻击的机理。