Oxygen Donor-Mediated Equilibration of Diastereomeric Alkene-Palladium(II) Intermediates in Enantioselective Desymmetrizing Heck Cyclizations was written by Machotta, Axel B.;Straub, Bernd F.;Oestreich, Martin. And the article was included in Journal of the American Chemical Society in 2007.Application of 2178-24-7 This article mentions the following:
This investigation examines the origin of enantioselection in the desymmetrization of an acyclic prochiral Heck cyclization precursor. High asym. induction (97-98% ee) is attributed to a temporary interaction of a Lewis basic oxygen donor with weakly Lewis acidic palladium(II). A series of control experiments combined with quantum-chem. model calculations provided sound evidence for a mechanism involving oxygen donor-mediated, rapid equilibration of diastereomeric alkene-palladium(II) complexes prior to the selectivity-determining ring-closing event, a Curtin-Hammett scenario. Our study also highlights the importance of the cationic pathway (triflate counter anions vs. halido ligand) and alkene stereochem. (E vs. Z) in asym. Heck reactions. In the experiment, the researchers used many compounds, for example, Ethyl (2-bromophenyl)acetate (cas: 2178-24-7Application of 2178-24-7).
Ethyl (2-bromophenyl)acetate (cas: 2178-24-7) belongs to organobromine compounds. A variety of minor organobromine compounds are found in nature, but none are biosynthesized or required by mammals. Organobromine compounds have fallen under increased scrutiny for their environmental impact. In the pharmaceutical industry organo bromine derivatives are used as sedatives, vasodilators, antiseptic agents, and anticancer agents.Application of 2178-24-7
Referemce:
Bromide – Wikipedia,
bromide – Wiktionary