Bromoethylene reaction

In the 1980s Shuie, D sa, Limero, Gigi Bear, and Bernard White were the doctoral students at Wentworth. The latter two studied negative ions in flames. Master s student Hernandez examined the response of the ECD at short reaction times. Limero studied fluorobenzenes. D sa discovered a fourth temperature region in the ECD for chloro and bromoethylenes. Limero, D sa, and Shuie researched electron capture in the atmospheric pressure chemical ionization system and obtained data for anion complexes using such equipment. Batten became intimately involved with this work. Lee and R. Ranatunga, the doctoral students of Zlatkis, made additional contributions. 

Acetylene reacts with iodine which has been covered with alcohol, and forms a di-iodide,C2H2I2. Acetylene does not appear to unite directly with hydrochloric acid with concentrated hydrobromic acid at 100° a reaction takes place slowly, and one molecule of the hydrocarbon and one of the halogen acid unite and form bromoethylene, H2C = CHBr. Under similar conditions with hydriodic acid, iodo-ethylene, H2C = CHI, and ethylidene iodide, CH3CHI2, are formed. Acetylene and hydrogen unite in the presence of finely-divided platinum to form ethane. 

The retro Diels-Alder reaction from the two 5-bromonorbornenes (I and II) expels bromoethylene to give a C5Hg+ ion (Equation 2.80), such as is found in Figures 2.46 and 2.49. 

Preparative Methods coupling of the Grignard reagent derived from ( )-2-(trimethylsilyl)-l-bromoethylene with the same bromo derivative leads to the silyldiene in 51% yield a higher yield (62%) is obtained by reaction of bis(trimethylsilyl)-methyllithium with ( )-3-(trimethylsilyl)-2-propenal. Other procedures involve the Pd°-catalyzed demercuration of bis[( )-(2-trimethylsilylvinyl)]mercury, prepared from (i )-2-(tri-methylsilyl)-l-lithioethylene and HgCE (77% yield)7 or the reaction of ( j-l,4-bis(trimethylsilyl)-2-butene with n-BuLi and TMEDA and subsequent oxidation with HgCl2 of the isolated bis-lithiated species, stabilized by complexation with TMEDA (57% yield). ... 

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