氟代二苯乙烯氨基酸的合成及性能

Synthesis and Properties of Fluostilbenic Amino Acids

以4-碘-L-苯丙氨酸为初始原料,经羧基和氨基的保护得到化合物2;化合物2与4-氟苯乙烯进行Heck反应得化合物3;化合物3脱去保护基得氟代二苯乙烯氨基酸(4,47.4%);其结构经1H NMR,13C NMR,IR和MS(ESI-TOF)确证。光学性质研究结果表明:4的激发、发射波长分别为314 nm和355 nm,斯托克斯位移为41 nm,荧光量子产率为0.22。化合物4在甲醇溶液中存在光致顺反异构现象,反式→顺式结构转变速率常数为0.026 min^-1。

Compound 2 was prepared from 4-iodo-L-phenylalanine via the protection of carboxyl and amino groups.Compound 3 was synthesized by the Heck reaction of 2 with 4-fluorostyrene,which was then deprotected to afford fluorostilbenic amino acid(4,47.4%).The structure of 4 was confirmed by 1H NMR,13C NMR,IR and MS(ESI-TOF).In addition,its optical property was studied.The results show that the excitation and emission wavelengths of 4 are 314 nm and 355 nm,respectively.The Stokes shift of it is 41 nm,and the quantum yield is 0.22.The photo-induced cis/trans isomerization of compound 4 in methanol solution was observed.The trans to cis isomerization rate is determined to be 0.026 min^-1 by UV-Vis.The 19F NMR spectra of compound 4 show that the chemical shifts of the fluorine atoms in the trans and cis structures are-115.22 and-115.53,respectively.