Application And Photophysical Properties Of New Benzothiopyranonesphotolabile Protecting Groups

Photolabile protecting groups can undergo deprotection reaction under a specific wavelength and release the protected compounds rapidly.The photodeprotection process can typically take place under neutral conditions without any chemical reagents.In this thesis,thiophenol was used as the original material to synthesize two kinds of the novel thiochromone-based photolabile protecting groups by condensation reaction,Suzuki-Miyaura coupling reaction,iodination reaction,oxidation reaction.Photolabile protecting groups are used for the following applications:Amino acids are the most basic substances to constitute the body protein and the life activities.Sulfonic acid compounds are important chemical intermediates,organic raw materials and also can play a good effect on catalytic in a variety of reactions.The photolabile protecting group with diazomethyl group as linker group was developed to react with the free acid form of amino acids and sulfonic acids under neutral conditions,which afforded the products in high yield.The photodeprotection reactions proceeded smoothly under photoirradiation to recover corresponding acids quantitatively.Propargylic alcohols are attractive,and have been extensively applied,as synthetic intermediates in modern organic synthesis.They can undergo nucleophilic substitution reactions under the catalysis of Lewis acid,which plays a very important role in the construction of carbon-carbon bond,carbon-nitrogen bond,carbon-oxygen bond.The byproduct of nucleophilic substitution reaction of propargyl alcohol is water,which can greatly reduce the environmental pollution.The photolabile protecting group with hydroxymethyl group as linker group was developed to react with propargylic alcohols and their derivatives,which afforded the products in high yield.Photodeprotection proceeded smoothly to give the corresponding propargylic alcohols,as demonstrated by 1H NMR spectroscopy,HPLC and fluorescence spectroscopy.Based on the special benzothiopyranone structure,the photoproducts showed high fluorescence quantum yield.This fluorescent characteristic demonstrated the photodeprotection progress also can be monitored by fluorescence spectra.The experimental results showed that the photolabile protecting groups can quantitatively release the protected substrates in a predetermined organic synthesis stage under a specific wavelength of light.