Murakami, Yukito published the artcileTransition-metal complexes of pyrrole pigments. 16. Cobalt complexes of 1,19-dimethyldehydrocorrins as vitamin B12 models, Name: 3-Bromo-2-methylpropanoic acid, the publication is Journal of the American Chemical Society (1980), 102(22), 6736-44, database is CAplus.
The Co complexes of 1,19-dimethyl-B,C-didehydrocorrin (BDHC) and its tetradehydro analog (TDHC), both having addnl. double bonds at peripheral positions and an addnl. angular Me group compared with the parent corrinoid, were investigated from the viewpoint of vitamin B12 chem. The electronic effect of peripheral double bonds in TDHC is significant, and the TDHC complex is far from analogous to the corrinoid, whereas the BDHC complex is quite analogous to the corrinoid as far as the electronic properties are concerned on the basis of their spectroscopic, electrochem., and axial coordination behaviors. The angular Me groups in the BDHC complex exert an usually large steric effect in the bimol. reactions of CoI(BDHC) with alkyl donors which result in the formation of an alkyl-Co bond. The steric interaction energies between an axial ligand and an angular Me and between an axial alkyl ligand and the macrocyclic skeleton are estimated from the kinetic and thermodn. data. The BDHC complex coordinated with a bulky alkyl ligand at its axial site undergoes a novel heterolytic C-Co bond cleavage in acidic media, giving Co(III) and a carbanionic intermediate under photolytic conditions and even in the dark. In reference to the electrochem. data for the BDHC complex and the related Co complexes, the significant steric pressure provided by BDHC on the bulky axial ligand is responsible for the heterolytic C-Co cleavage. Significance of the steric pressure effect is briefly discussed in connection with the mechanism for 1,2-rearrangement of substituents placed in the alkyl ligand. A synthetic usage of the BDHC complex as a catalyst for the selective reduction of a primary alkyl bromide is also described.
Journal of the American Chemical Society published new progress about 56970-78-6. 56970-78-6 belongs to bromides-buliding-blocks, auxiliary class Bromide,Carboxylic acid,Aliphatic hydrocarbon chain,Inhibitor, name is 3-Bromo-2-methylpropanoic acid, and the molecular formula is C4H7BrO2, Name: 3-Bromo-2-methylpropanoic acid.
Referemce:
https://en.wikipedia.org/wiki/Bromide,
bromide – Wiktionary