Scope of regioselective Suzuki reactions in the synthesis of arylpyridines and benzylpyridines and subsequent intramolecular cyclizations to azafluorenes and azafluorenones
作者:Joydev K. Laha、Ketul V. Patel、Saima Saima、Surabhi Pandey、Ganesh Solanke、Vanya Vashisht
DOI:10.1039/c8nj02734j
日期:——
current investigation on regioselective Suzuki reactions of 2,3-dihalopyridines and 2-halo-3-halomethylpyridines yielded the unexplored synthesis of arylpyridines and benzylpyridines bearing synthetic handles for further functionalization. Indeed, the scope of intramolecularcyclizations of arylpyridines and benzylpyridines prepared in this study for the synthesis of azafluorenes and azafluorenones has been
Cu-Mediated Direct Aryl CH Halogenation: a Strategy to Control Mono- and Di-Selectivity
作者:Zhi-Jun Du、Lian-Xun Gao、Ying-Jie Lin、Fu-She Han
DOI:10.1002/cctc.201300734
日期:2014.1
A protocol for the copper‐mediated directarylCHhalogenation is presented. Highly selective mono‐ and di‐halogenations are achieved by using acyl hypohalites, generated in situ from the readily available carboxylic acid and N‐halosuccinimides (NXS; X=Br and Cl) as powerful halogenating reagents. The correct choice of carboxylic acid additives and solvents is essential for both high yield and selectivity
提出了铜介导的直接芳基CH卤化的方案。通过使用酰基次卤酸盐来实现高度选择性的单卤化和二卤化,酰基次卤酸盐是由现成的羧酸和N-卤代琥珀酰亚胺(NXS; X = Br和Cl)原位生成的,作为强力卤化试剂。正确选择羧酸添加剂和溶剂对于高收率和选择性都至关重要。因此,使用廉价的铜催化剂和从容易负担得起且易于处理的羧酸和NXS(X = Br和Cl)原位生成酰基次卤酸盐卤化试剂的新策略为实际应用提供了优势。
Copper(ii)-catalyzed ortho-functionalization of 2-arylpyridines with acyl chlorides
作者:Wenhui Wang、Changduo Pan、Fan Chen、Jiang Cheng
DOI:10.1039/c0cc05557c
日期:——
Copper-catalyzed ortho-benzoxylation of 2-arylpyridine sp2 C–H bonds with acyl chloride is described. Notably, switching the base from t-BuOK to Li2CO3 causes chlorination of the C–H bond to take place.
Abstract Palladium-catalyzedchelation-assistedC–H bond halogenation of arenes using acid chlorides as chlorinating agents is reported. This method provides a monoselective, straightforward, and clean route for the construction of aryl chlorides as privileged motifs in organic transformations. Palladium-catalyzedchelation-assistedC–H bond halogenation of arenes using acid chlorides as chlorinating
copper-catalyzed C-H halogenation of 2-aryl-pyridinescontaining a variety of electron-withdrawing and electron-donatingsubstituents was described. It is worth noting that cheap and easy-to-handlelithium halides were utilized as the halogen sources.