Using pentafluorophenyl as a Lewis acid to stabilize a cis secondary amide conformation
Using pentafluorophenyl as a Lewis acid to stabilize a cis secondary amide conformation
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DOI：
10.1021/ol016733l
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发表时间：
2001-11-01
期刊：
影响因子：
5.2
通讯作者：
Smith, BD
中科院分区：
文献类型：
--
作者：
Forbes, CC;Beatty, AM;Smith, BD
[图表]N-（嘧啶-2-基）五氟苯甲酰胺在固态下采用顺式酰胺键，其中嘧啶基氮指向全氟苯基环的中心。在溶液中，该化合物是顺式和反式旋转异构体的混合物，构象平衡强烈依赖于溶剂，并且顺式旋转异构体是熵有利的。研究表明，顺式构象中两个芳基的溶剂化作用减弱是熵驱动力。
[GRAPHICS]N-(Pyrimidin-2-yl)pentafluorobenzamide adopts a cis amide bond in the solid state with a pyrimidyl nitrogen pointing toward the center of the perfluorophenyl ring. In solution, the compound is a mixture of cis and trans rotamers, The conformational equilibrium is strongly solvent dependent, and the cis rotamer is entropically favored. It is proposed that the entropic driving force is decreased solvation of the two aryl groups when in the cis conformation.