self-complementary tetrameric propargyl triols 8, 14, 18, and 21 were synthesized to investigate the duplex formation of self-complementary, ethynylene-linked UUAA, AAUU, UAUA, and AUAU analogues with integrated bases and backbone (ONIBs). The linear synthesis is based on repetitive Sonogashira couplings and C-desilylations (34–72% yield), starting from the monomeric propargyl alcohols 9 and 15 and the iodinated
自身互补的四聚体炔丙基三醇8,14,18,和21被合成到调查自身互补,亚
乙炔基联UU
AA,
AAUU,UAUA和AUAU类似物与集成碱和主链(ONIBs)的双链体形成。线性合成是基于
重复的Sonogashira偶联和Ç -desilylations(34-72%收率),从单体炔
丙醇开始9和15和
碘化核苷3,7,11,和13。从炔丙基OH基团到
腺苷单元N(3)的强持久分子内H键防止了gg
乙炔基在C(5')的分子类型取向。这样,形成环状双链体需要定向,该H键防止形成由所有四个碱基对连接的双链体。然而,UAUA和
AAUU类似物18和14的中央单元在CDCl 3 /(D 6)
DMSO 10∶1中缔合以形成以反向Hoogsteen碱基配对为特征的环状双链体。UU
AA四聚体8形成环状UU同型双链体,而AUAU四聚体21仅形成线性缔合体。O-甲
硅烷基化的UU
AA和
AAUU四聚体的双链体形成不再被阻止。互补