Photochemical and electrochemical behavior of thiophene-S-oxides

The photochemical and electrochemical behavior of thiophene-S-oxides as a class was studied for the first time. It was shown that in both cases deoxygenation of the S-O functionality takes place. The outcome of the photoirradiation is very dependent on the substituent pattern of the starting material. Thiophene-S-oxides show different reduction behaviors in presence and absence of proton donors. In the absence of proton donors the reduction potential of the compounds is dependent on the substituents of the molecules. In the presence of proton donors, the substituents play a less significant role 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 © 2000 John Wiley & Sons, Ltd.