On April 22, 2015, Saito, Yutaro; Segawa, Yasutomo; Itami, Kenichiro published an article.Category: ethers-buliding-blocks The title of the article was para-C-H Borylation of benzene derivatives by a bulky iridium catalyst. And the article contained the following:
A highly para-selective aromatic C-H borylation has been accomplished. By a new iridium catalyst bearing a bulky diphosphine ligand, Xyl-MeO-BIPHEP, the C-H borylation of monosubstituted benzenes can be affected with para-selectivity up to 91%. This catalytic system is quite different from the usual iridium catalysts that cannot distinguish meta- and para-C-H bonds of monosubstituted benzene derivatives, resulting in the preferred formation of meta-products. The para-selectivity increases with increasing bulkiness of the substituent on the arene, indicating that the regioselectivity of the present reaction is primarily controlled by steric repulsion between substrate and catalyst. Caramiphen, an anticholinergic drug used in the treatment of Parkinson’s disease, was converted into five derivatives via our para-selective borylation. The present [Ir(cod)OH]2/Xyl-MeO-BIPHEP catalyst represents a unique, sterically controlled, para-selective, aromatic C-H borylation system that should find use in streamlined, predictable chem. synthesis and in the rapid discovery and optimization of pharmaceuticals and materials. The experimental process involved the reaction of 2-(3-Methoxy-4-methylphenyl)-4,4,5,5-tetramethyl-1,3,2-dioxaborolane(cas: 1417036-28-2).Category: ethers-buliding-blocks
The Article related to boration monosubstituted benzene para selective iridium biphep catalyst, arylboronic ester preparation para selective boration aromatic substitution, Organometallic and Organometalloidal Compounds: Boron Compounds and other aspects.Category: ethers-buliding-blocks
Referemce:
Ether – Wikipedia,
Ether | (C2H5)2O – PubChem