Dynamic Kinetic Resolution of Biaryl Atropisomers via Peptide-Catalyzed Asymmetric Bromination was written by Gustafson, Jeffrey L.;Lim, Daniel;Miller, Scott J.. And the article was included in Science (Washington, DC, United States) in 2010.Safety of Methyl 2-bromo-4-fluorobenzoate This article mentions the following:
Despite the widespread use of axially chiral, or atropisomeric, biaryl ligands in modern synthesis and the occurrence of numerous natural products exhibiting axial chirality, few catalytic methods have emerged for the direct asym. preparation of this compound class. Here, the authors present a tripeptide-derived small-mol. catalyst for the dynamic kinetic resolution of racemic biaryl substrates. The reaction proceeds via an atropisomer-selective electrophilic aromatic substitution reaction using simple bromination reagents. The result is an enantioselective synthesis that delivers chiral nonracemic biaryl compounds with excellent optical purity and good isolated chem. yields (in most cases a >95:5 enantiomer ratio and isolated yields of 65 to 87%). A mechanistic model is advanced that accounts for the basis of selectivity observed In the experiment, the researchers used many compounds, for example, Methyl 2-bromo-4-fluorobenzoate (cas: 653-92-9Safety of Methyl 2-bromo-4-fluorobenzoate).
Methyl 2-bromo-4-fluorobenzoate (cas: 653-92-9) belongs to organobromine compounds. Bromine is more electronegative than carbon (2.9 vs 2.5). Consequently, the carbon in a carbon閳ユ彽romine bond is electrophilic, i.e. alkyl bromides are alkylating agents. The reactivity of organobromine compounds resembles but is intermediate between the reactivity of organochlorine and organoiodine compounds. For many applications, organobromides represent a compromise of reactivity and cost.Safety of Methyl 2-bromo-4-fluorobenzoate
Referemce:
Bromide – Wikipedia,
bromide – Wiktionary