1534433-35-6Relevant academic research and scientific papers
Nickel-Catalyzed oxidative coupling of unactivated C(sp3)-H bonds in aliphatic amides with terminal alkynes
Luo, Fei-Xian,Cao, Zhi-Chao,Zhao, Hong-Wei,Wang, Ding,Zhang, Yun-Fei,Xu, Xing,Shi, Zhang-Jie
, p. 18 - 21 (2017/04/04)
In this work, we demonstrated Ni-catalyzed oxidative coupling of unactivated C(sp3)-H bonds with terminal alkynes for construction of C(sp3)-C(sp) bonds to synthesize alkyl-substituted internal alkynes. Different amides exhibited good compatibility. Preliminary mechanistic studies were conducted to account for this alkynylation.
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.
Bridging C?H Activation: Mild and Versatile Cleavage of the 8-Aminoquinoline Directing Group
Berger, Martin,Chauhan, Rajan,Rodrigues, Catarina A. B.,Maulide, Nuno
supporting information, p. 16805 - 16808 (2016/11/16)
8-Aminoquinoline has emerged as one of the most powerful bidentate directing groups in history of C?H activation within the last decade. However, cleavage of its robust amide bond has shown to be challenging in several cases, thus jeopardizing the general synthetic utility of the method. To overcome this limitation, we herein report a simple oxidative deprotection protocol. This transformation rapidly converts the robust amide to a labile imide, allowing subsequent cleavage in a simple one-pot fashion to rapidly access carboxylic acids or amides as final products.
Copper(II)/Silver(I)-Catalyzed Sequential Alkynylation and Annulation of Aliphatic Amides with Alkynyl Carboxylic Acids: Efficient Synthesis of Pyrrolidones
Zhang, Jitan,Li, Danyang,Chen, Hui,Wang, Binjie,Liu, Zhanxiang,Zhang, Yuhong
, p. 792 - 807 (2016/03/09)
A highly efficient protocol for the synthesis of pyrrolidones by the copper-catalyzed alkynylation/annulation of aliphatic amides with alkynyl carboxylic acids is discussed in this paper. A broad range of easily accessible alkynyl carboxylic acids were introduced at the β-methyl group of aliphatic amides with the assistance of an 8-aminoquinolyl auxiliary group via decarboxylation to achieve the subsequent cyclic C-N bond formation within one hour. High selectivity of β-methyl groups over methylene groups was observed, and the extension of this catalytic system to the activation of methylene C-H bonds failed. The substrates with two different groups at the α-position of the aliphatic amides lead to the formation of diastereoisomers which is determined by 1H NMR spectroscopy. The initially produced products with Z-configurations can be easily transformed to the corresponding products with E-configurations by the treatment with dilute p-toluenesulfonic acid after the reaction. This catalytic tandem decarboxylative cyclization provides a new opportunity for the direct functionalization of sp3 C-H bonds.
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
, 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.
Cobalt-Catalyzed Cyclization of Aliphatic Amides and Terminal Alkynes with Silver-Cocatalyst
Zhang, Jitan,Chen, Hui,Lin, Cong,Liu, Zhanxiang,Wang, Chen,Zhang, Yuhong
, p. 12990 - 12996 (2015/10/28)
A new method of cobalt-catalyzed synthesis of pyrrolidinones from aliphatic amides and terminal alkynes was discovered through a C-H bond functionalization process on unactivated sp3 carbons with the silver cocatalyst using a bidentate auxiliary. For the first time, a broad range of easily accessible alkynes are exploited as the reaction partner in C(sp3)-H bond activation to give the important 5-ethylidene-pyrrolidin-2-ones in a site-selective fashion. The reaction tolerates a wide variety of functional groups including -F, -Cl, -Br, -CF3, ether, cyclopropane, and thiophene. Both pyridine ligand and aromatic solvent play the important role for the promotion of reactivity. This cobalt-catalyzed cyclization reaction can be successfully extended to a variety of aromatic amides to afford a variety of isoindolinones. Attractive features of this catalytic system include its low cost, easy operation, and convenient access to a wide range of pyrrolidinones and isoindolinones.
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 arylation of C(sp3)-H bonds in aliphatic amides via bidentate-chelation assistance
Aihara, Yoshinori,Chatani, Naoto
, p. 898 - 901 (2014/02/14)
The Ni-catalyzed, direct arylation of C(sp3)-H (methyl and methylene) bonds in aliphatic amides containing an 8-aminoquinoline moiety as a bidentate directing group with aryl halides is described. Deuterium-labeling experiments indicate that the C-H bond cleavage step is fast and reversible. Various nickel complexes including both Ni(II) and Ni(0) show a high catalytic activity. The results of a series of mechanistic experiments indicate that the catalytic reaction does not proceed through a Ni(0)/Ni(II) catalytic cycle, but probably through a Ni(II)/Ni(IV) catalytic cycle.
