作者:Norio Shibata、Biplab Kumar Das、Hiroshi Honjo、Yoshio Takeuchi
DOI:10.1039/b103170h
日期:——
A general strategy for the synthesis of nonpolar peptide nucleic acid monomers containing fluoroaromatics (F-PNA) is described. These compounds have been designed as hybrid analogues of the difluorotoluene nucleoside, F (1) with PNA. Fluorophenylacetic acid derivatives 9 were coupled to the Boc-protected pseudopeptide backbone 8 by a standard peptide coupling reaction using DhbtOH and DCC in the presence of triethylamine to afford the doubly protected F-PNA monomers 14 in moderate to good yields. The ethyl esters 14a, 14c and 14e underwent hydrolytic cleavage under basic conditions to generate N-protected F-PNA monomers 15 in good
yields. The tert-butyl esters 14b, 14d were treated with TFA in dichloromethane to produce the free F-PNA monomers 16 in good to excellent yields. The β-F-PNA monomers designed based on the structure of 2′,5′-linked isoDNA were also synthesized in a similar fashion to the preparation of F-PNA monomers in moderate to good yields as both N-protected and free monomers.
描述了一种合成含氟芳香环的非极性肽核酸单体(F-PNA)的一般策略。这些化合物被设计为二氟甲苯核苷(F-1)与PNA的杂化类似物。氟苯乙酸衍生物9通过标准肽偶联反应,在三乙胺存在下使用DhbtOH和DCC与Boc保护的伪肽骨架8偶联,以中等至良好的产率得到双重保护的F-PNA单体14。乙酯14a、14c和14e在碱性条件下发生水解裂解,以良好的产率生成N保护的F-PNA单体15。叔丁酯14b、14d用二氯甲烷中的TFA处理,以良好至优异的产率产生自由F-PNA单体16。基于2′,5′-连接的isoDNA结构的β-F-PNA单体也以与F-PNA单体制备相似的方式合成,以中等至良好的产率作为N保护和自由单体。