Photochemical and electrochemical behavior of thiophene-S-oxides

The photochemical and electrochemical behavior of thiophene-S-oxides as a c lass was studied for the first time. It was shown that in both cases deoxyg enation of the S-O functionality takes place. The outcome of the photoirrad iation is very dependent on the substituent pattern of the starting materia l. Thiophene-S-oxides show different reduction behaviors in presence and ab sence of proton donors. In the absence of proton donors the reduction poten tial of the compounds is dependent on the substituents of the molecules. In the presence of proton donors, the substituents play a less significant ro le and a number of thiophene-S-oxides were reduced electrochemically to the corresponding thiophenes in presence of a 10-fold excess of benzoic acid. Copyright (C) 2000 John Wiley & Sons, Ltd.