Intramolecular Thiotrifluoromethylation Of Alkynes For The Synthesis Of Trifluoromethylated Benzo[b]thiophenes

The trifluoromethyl group(CF3) is of great interest in pharmaceutical chemistry,agrochemistry and materials science because of its unique properties. As a consequence, numerous versatile and efficient methods to incorporate the CF3 group into target molecules have been reported. In this context, reactions that involve the selective difunctionalization of alkenes/alkynes have received increasing attention, as they enable the formation of C-C or C-heteroatom and C-CF3 bonds in a single synthetic operation. Thus, efficient methods for oxotrifluoromethylation,aminotrifluoromethylation and carbotrifluoromethylation reactions have been devised.Meanwhile, there are only a few reports on thiotrifluoromethylation of alkenes/alkynes.This thesis developed herein a novel method leading to various CF3-containing benzo[b]thiophenes. The by-product 3-iodobenzo[b]thiophene may be a new and powerful evidence of the electrophilic mechanism.The thesis includes the following four aspects.1. The development of difunctionalizing trifluoromethylation of alkenes/alkynes were reviewed. Such as, oxotrifluoromethylation, aminotrifluoromethylation,carbotrifluoromethylation, hydrotrifluoromethylation, etc.2. The thiotrifluoromethylation of alkynes for the synthesis of trifluoromethylated benzo[b]thiophenes was achieved for the first time. This method used TMSCF3/KF as the trifluoromethyl source, PIDA as the oxidant and Me CN as the solvent.3. Other trifluoromethyl source, Togni’s Reagent, was also applied to these transformations. The target product was achieved, though with a relative low yield.4. Possible applications in the pharmaceutical industry and material science of these trifluoromethylated benzo[b]thiophene were forecasted.