“…In our previous study, we have found that the 1,2-rearrangement, called a Fritsch-Buttenberg-Wiechell (FBW) rearrangement, 11 of magnesium alkylidene carbenoids 2 gives alkynes 3. 12 If excess Grignard reagents are used for this reaction, the resulting terminal alkynes 3 are expected to be deprotonated by Grignard reagents to give alkynylmagnesium chlorides. In this paper, we describe the generation of alkynylmagnesium chlorides from 1chlorovinyl p-tolyl sulfoxides 1 and Grignard reagents via the sulfoxide/magnesium exchange reaction, the FBW rearrangement of magnesium alkylidene carbenoids 2, and the deprotonation of terminal alkynes 3 with Grignard reagents.…”