Li, Zhao published the artcilePd-Catalyzed Suzuki coupling reactions of aryl halides containing basic nitrogen centers with arylboronic acids in water in the absence of added base, Category: pyridine-derivatives, the publication is New Journal of Chemistry (2017), 41(24), 15420-15432, database is CAplus.
The Pd-catalyzed Suzuki coupling reactions of a series of aryl chlorides and aryl bromides containing basic nitrogen centers with arylboronic acids in water in the absence of added base were reported. The reactions proceeded either partially or entirely under acidic conditions. After surveying twenty-two phosphorus ligands, high yields of products were obtained with aryl chlorides only when a bulky ligand, 2-(di-tert-butyl-phosphino)-1-phenyl-1H-pyrrole (cataCXiumPtB) was used. In contrast, aryl bromides produced high yields of products in the absence of both added base and added ligand. In order to explore the Suzuki coupling process entirely under acidic conditions, a series of reactions were conducted in buffered acidic media using several model substrates. 4-Chlorobenzylamine, in the presence of cataCXiumPtB, produced high yields of product at buffered pH 6.0; the yields dropped off precipitously at buffered pH 5.0 and lower. The fall-off in yield was attributed to the decomposition of the Pd-ligand complex due to the protonation of the ligand in the more acidic aqueous media. In contrast, in the absence of an added ligand, 4-amino-2-chloropyridine produced quant. yields at buffered pH 3.5 and 4.5 while 4-amino-2-bromopyridine produced quant. yields in a series of buffered media ranging from pH 4.5 to 1.5. These substrates were only partially protonated in acidic media and could behave as active Pd ligands in the Suzuki catalytic cycle.
New Journal of Chemistry published new progress about 39856-58-1. 39856-58-1 belongs to pyridine-derivatives, auxiliary class Pyridine,Bromide,Amine, name is 2-Bromopyridin-3-amine, and the molecular formula is C5H5BrN2, Category: pyridine-derivatives.
Referemce:
https://en.wikipedia.org/wiki/Pyridine,
Pyridine | C5H5N – PubChem