1541196-41-1Relevant articles and documents
Unexpected Stability of CO-Coordinated Palladacycle in Bidentate Auxiliary Directed C(sp3)-H Bond Activation: A Combined Experimental and Computational Study
Jiang, Yi,Zhang, Shuo-Qing,Cao, Fei,Zou, Jiao-Xia,Yu, Jing-Lu,Shi, Bing-Feng,Hong, Xin,Wang, Zhen
, p. 2022 - 2030 (2019)
We have thoroughly studied four kinds of different palladacycles with 8-aminoquinoline as the auxiliary and carbon monoxide (CO), acetonitrile (CH3CN), pyridine, and dimethyl sulfoxide (DMSO) as the ligands, respectively, using crystallographic analysis, cyclic voltammetry (CV), stoichiometric reactions, and computational calculations. A higher oxidation potential in CV and lower chemical reactivities to react with weaker electrophilic reagents are presented for CO-coordinated palladacycles, which has been supported by DFT studies that the CO-coordinated Pd complex has the highest ΔG value for the initial ligand exchange process. Meanwhile, a rigid structure can be observed and relatively high activation energy (ΔG? = 54.2 kcal/mol) is needed for further migratory insertion. All this evidence suggests that the CO-coordinated Pd complex is a kinetically and thermodynamically stable intermediate, which accounts for its reluctance for migratory insertion and the formation of the corresponding carbonylation product.
Nickel-catalysed direct alkylation of thiophenes via double C(sp3)-H/C(sp2)-H bond cleavage: The importance of KH2PO4
Wang, Xie,Xie, Peipei,Qiu, Renhua,Zhu, Longzhi,Liu, Ting,Li, You,Iwasaki, Takanori,Au, Chak-Tong,Xu, Xinhua,Xia, Yuanzhi,Yin, Shuang-Feng,Kambe, Nobuaki
, p. 8316 - 8319 (2017/07/26)
A Ni-catalyzed oxidative C-H/C-H cross-dehydrogenative coupling (CDC) reaction was developed for constructing various highly functionalized alkyl (aryl)-substituted thiophenes. This method employs thiophenes and aliphatic (aromatic) amides that contain an 8-aminoquinoline as a removable directing group in the presence of a silver oxidant. The approach enables the facile one-step synthesis of substituted thiophenes with high functional group compatibility via double C-H bond cleavage without affecting C-Br and C-I bonds. DFT calculations verify the importance of KH2PO4 as an additive for promoting C-H bond cleavage and support the involvement of a Ni(iii) species in the reaction.
Nickel-Catalyzed Aminoxylation of Inert Aliphatic C(sp3)-H Bonds with Stable Nitroxyl Radicals under Air: One-Pot Route to α-Formyl Acid Derivatives
Wang, Chunxia,Zhang, Luoqiang,You, Jingsong
supporting information, p. 1690 - 1693 (2017/04/11)
Nickel-catalyzed aminoxylation of an unactivated C(sp3)-H bond with a stable nitroxyl radical has been accomplished for the first time to offer various N-alkoxyamine derivatives, which further enables a one-pot approach to α-formyl acid derivatives. The aminoxylation process reported also provides direct evidence for the oxidative addition of a cyclometallic intermediate with a free radical, which is helpful for the reaction-mechanism study in transition-metal-catalyzed functionalization of inert C(sp3)-H bonds.
Iron-Catalyzed Directed C(sp2)-H and C(sp3)-H Functionalization with Trimethylaluminum
Shang, Rui,Ilies, Laurean,Nakamura, Eiichi
supporting information, p. 7660 - 7663 (2015/06/30)
Conversion of a C(sp2)-H or C(sp3)-H bond to the corresponding C-Me bond can be achieved by using AlMe3 or its air-stable diamine complex in the presence of catalytic amounts of an inorganic iron(III) salt and a diphosphine along with 2,3-dichlorobutane as a stoichiometric oxidant. The reaction is applicable to a variety of amide substrates bearing a picolinoyl or 8-aminoquinolyl directing group, enabling methylation of a variety of (hetero)aryl, alkenyl, and alkyl amides. The use of the mild aluminum reagent prevents undesired reduction of iron and allows the reaction to proceed with catalyst turnover numbers as high as 6500.
Nickel-catalyzed direct thiolation of C(sp3)-H bonds in aliphatic amides
Wang, Xie,Qiu, Renhua,Yan, Chunyang,Reddy, Vutukuri Prakash,Zhu, Longzhi,Xu, Xinhua,Yin, Shuang-Feng
supporting information, p. 1970 - 1973 (2015/04/27)
Nickel-catalyzed thiolation of the inactivated methyl C(sp3)-H bonds of aliphatic amides with disulfide is described. It is a novel strategy for the synthesis of thioethers with the ultimate goal of generating thioether carboxylic acids with various functional groups.
Nickel-Catalyzed Direct C (sp3)-H Arylation of Aliphatic Amides with Thiophenes
Wang, Xie,Zhu, Longzhi,Chen, Sihai,Xu, Xinhua,Au, Chak-Tong,Qiu, Renhua
supporting information, p. 5228 - 5231 (2015/11/18)
Nickel-catalyzed heteroarylation of the inactive methyl C(sp3)-H bond of aliphatic amide with heteroarenes is described. The method takes advantage of chelation assistance by an 8-aminoquinolinyl moiety. The synthetic reaction has good tolerance toward functional groups, and it can be used in the construction of various kinds of alkyl-substituted heteroarenes.
Nickel-catalyzed direct thiolation of unactivated C(sp3)-H bonds with disulfides
Yan, Sheng-Yi,Liu, Yue-Jin,Liu, Bin,Liu, Yan-Hua,Zhang, Zhuo-Zhuo,Shi, Bing-Feng
supporting information, p. 7341 - 7344 (2015/04/27)
The first nickel-catalyzed thiolation of unactivated C(sp3)-H bonds with disulfides was described. This transformation uses (dppp)NiCl2 as a catalyst and BINOL as a ligand, which are efficient for the thiolation of β-methyl C(sp
Nickel-catalyzed site-selective alkylation of unactivated C(sp 3)-H bonds
Wu, Xuesong,Zhao, Yan,Ge, Haibo
, p. 1789 - 1792 (2014/03/21)
The direct alkylation of unactivated sp3 C-H bonds of aliphatic amides was achieved via nickel catalysis with the assist of a bidentate directing group. The reaction favors the C-H bonds of methyl groups over the methylene C-H bonds and tolerates various functional groups. Moreover, this reaction shows a predominant preference for sp3 C-H bonds of methyl groups via a five-membered ring intermediate over the sp2 C-H bonds of arenes in the cyclometalation step.
