Selective and efficient syntheses of phototoxic 2,2':5',2''-terthiophene derivatives bearing a functional substituent in the 3'- or the 5-position

Article abstract of DOI:10.1016/S0040-4020(01)96185-X

Efficient and selective procedures have been developed to prepare on a medium scale several phototoxic 2,2':5',2''-terthiophene derivatives of general formula 2 and 3, which are characterized by a functional substituent in the 3'- or the 5-position. Most of these procedures, which are based on the construction of the 2,2':5',2''-terthiophene moiety and involve palladium-mediated carbon-carbon bond forming reactions, allow to overcome synthetic difficulties that may be found in the synthesis of compounds 2 and 3 starting from 2,2':5',2''-terthiophene (1a).