Negishi, Eiichi published the artcileCyclization reactions of ω-tosyloxy-1-alkynyl- and ω-tosyloxy-1-alkenylborates and their ω-halo analogs, Name: (4-Bromobut-1-yn-1-yl)trimethylsilane, the publication is Heteroatom Chemistry (1992), 3(3), 293-302, database is CAplus.
The reaction of trialkylboranes with ω-tosyloxy-1-lithio-1-alkynes can induce transfer of an alkyl group from the boron atom to the alkynyl carbon atom with concomitant formation of four- through six-membered carbocycles via intramol. displacement of the ω-tosyloxy group. Thus, reacting LiCCCH2CMe2(CH2)3OSO2C6H4Me-4 with tricyclopentylborane gave a mixture of (E)- and (Z)-cyclopentylmethylene-3,3-dimethylcyclohexane. The stereoselectivity of the reaction, however, is low (anti/syn≃1.6-1.7). The corresponding reaction of ω-halo- or ω-tosyloxy-1-alkenylborates also gives exocyclic alkenes via 1,2-migration-cyclization followed by dehydroboration. In the cases of cyclopropanation, cyclopropylcarbinyl-to-homopropargyl rearrangement rather than dehydroboration takes place. Diphenylzirconocene reacts similarly with 6-lithio-5-hexynyl tosylate to give phenylmethylenecyclopentane in 45% yield. On the other hand, attempts to induce a similar migration with Ph derivatives of Y, V, Cr, and Mn have led to < 5-10% yields of the same cyclization product.
Heteroatom Chemistry published new progress about 69361-41-7. 69361-41-7 belongs to bromides-buliding-blocks, auxiliary class PROTAC Linker,Aliphatic Linker, name is (4-Bromobut-1-yn-1-yl)trimethylsilane, and the molecular formula is C7H13BrSi, Name: (4-Bromobut-1-yn-1-yl)trimethylsilane.
Referemce:
https://en.wikipedia.org/wiki/Bromide,
bromide – Wiktionary