New Phototriggers:<sup>1</sup> Extending the <i>p</i>-Hydroxyphenacyl π−π* Absorption Range
作者:Peter G. Conrad、Richard S. Givens、Jörg F. W. Weber、Karl Kandler
DOI:10.1021/ol005856n
日期:2000.6.1
[equation--see text] Introducing 3-methoxy or 3,5-dimethoxy substituents on the 4-hydroxyphenacyl (pHP) photoremovable protecting group has been explored with two excitatory gamma-amino acids, L-glutamic acid and gamma-amino butyric acid (GABA). These substituents significantly extend the absorption range of the pHP chromophore, e.g., the tail of absorption bands of 2a,b extend above 400 nm, well beyond
[等式-见正文]已经研究了用两种兴奋性γ-氨基酸(L-谷氨酸和γ-氨基丁酸)在4-羟基苯甲酰基(pHP)可光除去的保护基上引入3-甲氧基或3,5-二甲氧基取代基的方法。 (GABA)。这些取代基显着扩展了pHP发色团的吸收范围,例如2a,b的吸收带的尾部延伸超过400 nm,远远超出了芳香族氨基酸和核苷酸的吸收。辐照释放出氨基酸的速率常数约为10(7)s(-)(1),外观效率(Phi(app))为0.03-0.04。光产物是通过pHP激发三重态形成的,主要是光还原和光水解的产物。1a,b也重新排列为苯乙酸3。