Caged glutamates with π-extended 1,2-dihydronaphthalene chromophore: design, synthesis, two-photon absorption property, and photochemical reactivity.

Caging and photochemical uncaging of the excitatory neurotransmitter L-glutamate (glu) offers a potentially valuable tool for understanding the mechanisms of neuronal processes. Designing water-soluble caged glutamates with the appropriate two-photon absorption property is an attractive strategy to achieve this. This paper describes the design, synthesis, and photochemical reactivity of caged glutamates with pi-extended 1,2-dihydronaphthalene structures, which possess a two-photon cross-section of similar to 120 GM and an excellent buffer solubility (up to 115 mM). High yields up to 99% glutamate were observed in the photolysis of two caged glutamates. Suzuki-Miyaura cross-coupling and Buchwald-Hartwig amination were used as the key reactions to synthesize the caged compounds.