Acetylenic and Polyacetylenic Compounds Derived from Thiophene, Furan, and p-Dibromobenzene Using 1,1-Dichloro-2,2-difluoroethene

Article abstract of DOI:10.1246/bcsj.54.2045

Compounds of the type AZCF=CCl2, prepared from AZA (thiophene, furan, and p-dibromobenzene; Z = 2,5-thiophenediyl, 2,5-furandiyl, and p-phenylene; A = H or Br), were converted into CCl2=CFZC<*>CH, CCl2=CFZC<*>CCF=CCl2, and CCl2=CFZC<*>CSi(CH3)3 in a one-flask procedure via LiZC<*>CLi.The products were further converted into acetylenic compounds such as (CH3)3SiC<*>CZC<*>CSi(CH3)3 and (CH3)3SiC<*>CZC<*>C-C<*>CSi(CH3)3. 1-Ethynyl-4-(1,3-butadiynyl)benzene was izolated. 2,5-Diethynylthiophene and -furan were prepared in two steps from thiophene and furan, respectively, via CCl2=CFZCF=CCl2.By treatment with copper (II) acetate hydrate in pyridine, (CCl2=CFZC<*>C-)2 were obtained not only from CCl2=CFZC<*>CH but also from CCl2=CFZC<*>CSi(CH3)3.