In 2017,Chen, Fu-Min; Huang, Fei-Dong; Yao, Xue-Yi; Li, Tian; Liu, Feng-Shou published 《Direct C-H heteroarylation by an acenaphthyl-based α-diimine palladium complex: improvement of the reaction efficiency for bi(hetero)aryls under aerobic conditions》.Organic Chemistry Frontiers published the findings.Reference of 5-Bromo-2-chloropyridine The information in the text is summarized as follows:
A bulky acenaphthyl skeleton-based α-diimine palladium complex with ortho-tert-Bu on N-aryl moieties was designed, synthesized and characterized. The developed palladium complex was applied for direct C-H arylation under aerobic reaction conditions. A range of heteroaryls, such as thiazoles, thiophenes, furans, imidazopyridines, indolizines, isoxazoles, imidazoles, triazoles, pyrazoles, indoles, pyrroles and pyrazolidinones, were used, while various coupling partners of heteroaryl bromides with wide functional groups were compatible. Upon using 0.05-0.1 mol% of a precatalyst, more than 90 examples of cross-coupling products were afforded in good to excellent yields, demonstrating that this phosphine-free catalytic system scaffold enables a general access to biheteroaryls. After reading the article, we found that the author used 5-Bromo-2-chloropyridine(cas: 53939-30-3Reference of 5-Bromo-2-chloropyridine)
5-Bromo-2-chloropyridine(cas: 53939-30-3) belongs to pyridine. Pyridine is very deactivated towards electrophilic substitution with respect to benzene. For this reason classical formylation, using methods such as the Gattermann or Vilsmeier reactions, are not generally successful. Reference of 5-Bromo-2-chloropyridine