Application of diphenyl phosphorazidate (DPPA) to the synthesis of peptides revealed that the DPPA method is quite general because it can be applied to the formation of peptides containing various functional groups. No difficulties were encountered when the side chains of serine, threonine, valine, glutamine, asparagine, methionine, histidine, tryptophan, and pyroglutamic acid were present in the carboxyl component. Arginine and cysteine showed no trouble when their side chain functions were protected with the nitro and benzyl groups, respectively. Serine, tyrosine, and histidine could be used as the amino component without any protection of the side chains. Fragment coupling of N-benzyloxycarbonylleucylleucine with valylphenylalanine methyl ester hydrochloride by DPPA showed that no racemization occurred.
将
磷酸二苯酯(
DPPA)应用于
多肽合成的结果表明,
DPPA 方法具有很强的通用性,因为它可以用于合成含有各种官能团的
多肽。当羧基成分中含有
丝氨酸、苏
氨酸、缬
氨酸、谷
氨酰胺、天冬酰胺、蛋
氨酸、组
氨酸、色
氨酸和焦谷
氨酸的侧链时,没有遇到任何困难。当精
氨酸和半胱
氨酸的侧链功能分别受到硝基和苄基的保护时,不会出现问题。
丝氨酸、
酪氨酸和组
氨酸可用作
氨基成分,无需对侧链进行任何保护。用
DPPA 将
N-苄氧羰基亮
氨酸与
戊基苯丙
氨酸甲酯盐酸盐进行片段偶联,结果表明没有发生外消旋现象。