Boardman, Larry D. published the artcileMetal promoted cyclization. 5. Mechanistic duality in cycloalkylation of alkenylmetal derivatives, Safety of (4-Bromobut-1-yn-1-yl)trimethylsilane, the publication is Journal of the American Chemical Society (1984), 106(20), 6105-7, database is CAplus.
Cycloalkylation of ω-halo-1-alkenylmetals can proceed by either a σ- or a π-type cyclization process. The σ-process, observed with alkenyllithium derivatives, is applicable to the formation of four- through seven-membered cycloalkenes. It does not require the second metal, e.g., Si, but requires the cis relationship between Li and the cyclizing moiety, and is regiospecific. The required (Z)-1-iodo-ω-bromo-1-alkenes may conveniently be prepared via carbometalation of alkynes with alkenylmetals followed by iodinolysis, treatment with (Me2CHCH2)3Al-Cl2ZrCp2, and brominolysis with NBS. On the other hand, the π-process, observed with 1,1-dimetallo-ω-halo-1-alkenes (I, M1 = Al, Zn, Zr, Si; M2 = Si, Zn, Al, Zr; R = H, alkyl; X = halo) has been applied to the synthesis of three-, four-, and six-membered cycloalkenes, the relative ease of cyclization being 3, 4 ≫ 5 < 6. This process seems to require two metals, but the alkene geometry is unimportant. It can be regioselective but nonregiospecific.
Journal of the American Chemical Society 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, Safety of (4-Bromobut-1-yn-1-yl)trimethylsilane.
Referemce:
https://en.wikipedia.org/wiki/Bromide,
bromide – Wiktionary