作者:Xin Sonia Gai、Basil A. Coutifaris、Scott H. Brewer、Edward E. Fenlon
DOI:10.1039/c0cp02774j
日期:——
The synthesis of 2′-azido-5-cyano-2′-deoxyuridine, N333CNdU (1), from trityl-protected 2′-amino-2′-deoxyuridine was accomplished in four steps with a 12.5% overall yield. The IR absorption positions and profiles of the azide and nitrile group of N333CNdU were investigated in 14 different solvents and water/DMSO solvent mixtures. The azide probe was superior to the nitrile probe in terms of its extinction coefficient, which is 2–4 times larger. However, the nitrile IR absorbance profile is generally less complicated by accidental Fermi resonance. The IR frequencies of both probes undergo a substantial red shift upon going from water to aprotic solvents such as THF or DMSO. DFT calculations supported the hypothesis that the molecular origin of the higher observed frequency in water is primarily due to hydrogen bonds between the probes and water molecules.
以三苯甲基保护的 2′-氨基-2′-脱氧尿苷为原料,分四步合成了 2′-叠氮-5-氰基-2′-脱氧尿苷 N333CNdU (1),总收率为 12.5%。研究了 N333CNdU 的叠氮基和腈基在 14 种不同溶剂和水/DMSO 混合溶剂中的红外吸收位置和曲线。叠氮探针的消光系数是腈探针的 2-4 倍,优于腈探针。不过,腈的红外吸收曲线一般不会受到费米共振的影响。从水到四氢呋喃或二甲基亚砜等惰性溶剂时,两种探针的红外频率都会发生很大的红移。DFT 计算支持这样的假设,即在水中观察到的较高频率主要是探针与水分子之间的氢键造成的。