Negishi, Eiichi published the artcileNovel silicon-promoted cycloalkylation of alkenylmetal derivatives, Category: bromides-buliding-blocks, the publication is Journal of the American Chemical Society (1983), 105(20), 6344-6, database is CAplus.
Two novel cycloalkylation reactions of alkenylmetals, in which Si plays subtle but critical roles, are described. Such cycloalkylation reactions appear to be unprecedented. Significantly, neither appears to be affected by the stereochem. integrity of alkenylmetal intermediates. Together, they provide novel and convenient routes to cycloalkenylsilanes. X(CH2)2CCSiMe3 (I, X = C, Br, I) are either hydroaluminated with diisobutylaluminum hydride or carboaluminated with Me3Al-Cl2ZrCp2 in nonpolar solvents, such as hexane, benzene or (CH2Cl)2, and were converted into 1-trimethylsilyl-1-cyclobutene and its derivatives in 80-100% yields. The available data suggest that the reaction involves a π-type process via cyclopropylcarbinyl cationic series. A similar reaction occurs with 1-trimethylsilylpropargyl bromide. Its reaction with Me3Al-Cl2ZrCp2 gives II instead of III. Application of the method to the preparation of five- and six-membered alkenylsilanes have not been successful. Fortunately, an alternate procedure was developed which presumably involves a σ-type process. Thus, treatment of appropriate ω-bromo-1-trimethylsilyl-1-iodo-1-alkenes with 2 equivalent of Me3CLi in ether at -78° followed by gradual warming has produced 1-trimethyl-1-cycloalkenes containing four-, five-, and six-membered rings in 64-81% yields. The synthetic utility of these cyclization reactions may be indicated by a 4-step conversion of I to grandisol (IV) as a 2:1 mixture of the Z and E isomers in overall 40% yield.
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, Category: bromides-buliding-blocks.
Referemce:
https://en.wikipedia.org/wiki/Bromide,
bromide – Wiktionary