Palladium-catalyzed ortho-nitration of 2-arylbenzoxazoles
摘要:
An efficient and general protocol for palladium-catalyzed chelation-assisted ortho-nitration of 2-arylbenzoxazoles has been developed. This nitration exhibits high regioselectivity for the substrates, and the reaction could tolerate many functional groups such as F, Cl, Br, CH3, CH3O, affording ortho-nitration products in moderate to good yields. Moreover, some 2-arylbenzoxazole heterocyclic analogues proceed well under this catalytic system. Further studies have been performed to obtain insight into the mechanism. (C) 2015 Elsevier Ltd. All rights reserved.
Chelating palladium complexes containing pyridine/pyrimidine hydroxyalkyl di-functionalized N-heterocyclic carbenes: synthesis, structure, and catalytic activity towards C–H activation
作者:Liangru Yang、Jinwei Yuan、Pu Mao、Qi Guo
DOI:10.1039/c5ra21183b
日期:——
novel chelating palladium complexes containing pyridine/pyrimidine hydroxyalkyl di-functionalized N-heterocyclic carbenes (NHCs) via direct metallation of the precursor imidazolium salts is presented. The structure has been characterized unambiguously by X-ray single crystal analysis. Catalytic activity investigation showed that the complexes catalyse the direct C–H bond arylation of (benzo)oxazoles efficiently
Palladium-catalyzed desulfitative arylation of azoles with arylsulfonyl hydrazides
作者:Xinzhang Yu、Xingwei Li、Boshun Wan
DOI:10.1039/c2ob26270c
日期:——
Palladium-catalyzed desulfitative and denitrogenative arylation of azoles with arylsulfonylhydrazides has been achieved. A broad scope of azoles and arylsulfonylhydrazides has been used to produce arylated azoles in high yields.
A highly efficient palladium-catalyzed arylation of azoles at the C2-position using 1-aryltriazenes as aryl reagents was developed. Azoles including oxazoles, thiazoles, imidazoles, 1,3,4-oxadiazoles, and oxazolines could react with 1-aryltriazenes smoothly to generate the corresponding products in good to excellent yields, and various substitution patterns were tolerated toward the reaction.
Direct arylation of benzoxazole C–H bonds with iodobenzene diacetates
作者:Peng Yu、Guangyou Zhang、Fan Chen、Jiang Cheng
DOI:10.1016/j.tetlet.2012.06.076
日期:2012.8
A Pd (OAc)2-catalyzed direct arylation of benzoxazoleC–H bonds has been achieved with iodobenzene diacetates as the arylation reagent in moderate to good yields. The procedure tolerates a series of functional groups, such as methoxy, nitro, cyano, chloro, and bromo groups.
Unsymmetrical Pincer <i>N</i>-Heterocyclic Carbene–Nitrogen–Phosphine Chelated Palladium(II) Complexes: Synthesis, Structure, and Reactivity in Direct Csp<sup>2</sup>–H Arylation of Benzoxazoles
作者:Yaqiu Li、Xiaojun Yu、Yangdiandian Wang、Haiyan Fu、Xueli Zheng、Hua Chen、Ruixiang Li
DOI:10.1021/acs.organomet.8b00005
日期:2018.3.26
unsymmetrical pincer N-heterocyclic carbene–nitrogen–phosphine (CNP) and its palladiumcomplexes PdCl2(κ2-CP) (4) and [PdCl(κ3-CNP)]PF6 (5·PF6) were synthesized. NMR spectra disclosed that the transformation of complex 4 structure occurred in the solution. Further NMR experimental and single crystal structure analysis of complex 4 provided unequivocal and structural evidence for the formation of complex [PdCl(κ3-CNP)]Cl