Preparation of (E)-1,2-Bis(2,2'-bithiophene-5-yl)ethylene and (E)-1,2-Bis-(2,2':5',2''-terthiophene-5-yl)ethylene

E)-1,2-Bis(2,2'-hithiaphene-5-yl)ethylene and (E)-1,2-his(2,2':5',2"-terthiophene-5-yl)ethylene were synthesized by reductive coupling reaction of 2,2'-hithiophene-5-carhaldehyde and 2,2':5',2"-terthiophene-5-carbaldehyde, respectively, using a law-valent titanium reagent prepared from titanium(1V) chloride and zinc powder in tetrahydrofuran.Bioactivities of bithiophenes and terthiophenes are recently receiving much attention.The most carefully scrutinized of these compounds is 2,2':5',ZWterthiophene (L!) .