Conformational dynamics of 4-aryl-1,4-dihydropyridine calcium channel antagonists. 1. Quantitation of C4-C1′ bond rotational barriers
作者:Robert B. Palmer、Niels H. Andersen
DOI:10.1016/0040-4020(96)00500-5
日期:1996.7
Thermodynamic activation parameters for aryl ring rotation were determined for all six compounds from linear Eyring plots which span four orders of magnitude. The barrier to rotation about the ring juncture was also calculated at the AM1 level and these calculations correctly predict the general magnitude, though not the specific barriers, to rotation. The asymmetrically substituted compound, 1,4-dihydro-2
使用饱和转移,差值NOE和可变温度NMR光谱研究了六个取代的4-芳基-1,4-二氢吡啶钙通道拮抗剂类似物的溶液状态动力学。从跨越四个数量级的线性Eyring图确定了所有六种化合物的芳基环旋转的热力学激活参数。还可以在AM1级别上计算绕环接合点旋转的障碍,这些计算正确地预测了旋转的一般幅度,尽管不是特定的障碍。不对称取代的化合物1,4-二氢-2,6-二甲基-4-(2'-氯-6-甲基苯基)-3,5-吡啶-二羧酸二甲酯(2a)的旋转异构度为1.7通过NMR鉴定具有芳基甲基顺式的1∶1至二氢吡啶环的C4H;AM1正确地预测了这种偏爱,但是高估了它的大小。在晶体状态下,旋转异构体比例似乎接近1:1。