850567-56-5Relevant articles and documents
Para-Selective C-H Borylation of Common Arene Building Blocks Enabled by Ion-Pairing with a Bulky Countercation
Mihai, Madalina T.,Williams, Benjamin D.,Phipps, Robert J.
supporting information, p. 15477 - 15482 (2019/10/11)
The selective functionalization of C-H bonds at the arene para position is highly challenging using transition metal catalysis. Iridium-catalyzed borylation has emerged as a leading technique for arene functionalization, but there are only a handful of strategies for para-selective borylation, which operate on specific substrate classes and use bespoke ligands or catalysts. We describe a remarkably general protocol which results in para-selectivity on some of the most common arene building blocks (anilines, benzylamines, phenols, benzyl alcohols) and uses standard borylation ligands. Our strategy hinges upon the facile conversion of the substrates into sulfate or sulfamate salts, wherein the anionic arene component is paired with a tetrabutylammonium cation. We hypothesize that the bulk of this cation disfavors meta-C-H borylation, thereby promoting the challenging para-selective reaction.
Synthesis of trimethylstannyl arylboronate compounds by sandmeyer-type transformations and their applications in chemoselective cross-coupling reactions
Qiu, Di,Wang, Shuai,Tang, Shengbo,Meng, He,Jin, Liang,Mo, Fanyang,Zhang, Yan,Wang, Jianbo
, p. 1979 - 1988 (2014/04/03)
A synthetic method based on Sandmeyer-type reactions to access both tin- and boron-substituted arenes from nitroaniline derivatives is described. This transformation can be applied to the synthesis of a series of functionalized trimethylstannyl arylboronates. In addition, the chemoselective reaction of the Stille and Suzuki-Miyaura cross-coupling reactions is explored, and a series of m- and p-terphenyl derivatives have been synthesized by conducting consecutive one-pot Stille and Suzuki-Miyaura cross-coupling reactions.
