857772-05-5Relevant academic research and scientific papers
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)
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 thioetherification of β-C(sp3)-H bonds of aliphatic amides
Lin, Cong,Yu, Wenlong,Yao, Jinzhong,Wang, Bingjie,Liu, Zhanxiang,Zhang, Yuhong
supporting information, p. 1340 - 1343 (2015/03/14)
The nickel-catalyzed β-thioetherification of unactivated C(sp3)-H bond of propionamides is established with the assistance of 8-aminoquinoline auxiliary, leading to the β-thio carboxylic acid derivatives. A broad range of functional groups is compatible with this thioetherfication reaction. The process represents the first successful example of metal-catalyzed C-S bond formation from unactivated C(sp3)-H bonds.
Copper-mediated aryloxylation and vinyloxylation of β-C(sp3)-H bond of propionamides with organosilanes
Zhang, Jitan,Chen, Hui,Wang, Binjie,Liu, Zhanxiang,Zhang, Yuhong
supporting information, p. 2768 - 2771 (2015/06/16)
A novel copper-mediated method for the aryloxylation and vinyloxylation of β-C(sp3)-H bonds of propioamides with organosilanes is described. The reaction proceeds with the assistance of an 8-aminoquinolyl auxiliary in a tandem way by the first oxidation of β-C(sp3)-H bonds and subsequent arylation/vinylation to give the aryloxylation/vinyloxylation products. This unusual aryloxy/vinyloxy forming reaction offers a new avenue for the functionalization of unactivated sp3 C-H bonds in organic synthesis.
Cobalt-Catalyzed Cyclization of Aliphatic Amides and Terminal Alkynes with Silver-Cocatalyst
Zhang, Jitan,Chen, Hui,Lin, Cong,Liu, Zhanxiang,Wang, Chen,Zhang, Yuhong
supporting information, 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.
Iron-catalyzed C(sp2)-H and C(sp3)-H arylation by triazole assistance
Gu, Qing,Al Mamari, Hamad H.,Graczyk, Karolina,Diers, Emelyne,Ackermann, Lutz
supporting information, p. 3868 - 3871 (2014/05/06)
Modular 1,2,3-triazoles enabled iron-catalyzed C-H arylations with broad scope. The novel triazole-based bidentate auxiliary is easily accessible in a highly modular fashion and allowed for user-friendly iron-catalyzed C(sp 2)-H functionalizations of arenes and alkenes with excellent chemo- and diastereoselectivities. The versatile iron catalyst also proved applicable for challenging C(sp3)-H functionalizations, and proceeds by an organometallic mode of action. The triazole-assisted C-H activation strategy occurred under remarkably mild reaction conditions, and the auxiliary was easily removed in a traceless fashion. Intriguingly, the triazole group proved superior to previously used auxiliaries. With a little help: A versatile iron catalyst allows the arylation of C(sp2)-H and C(sp3)-H bonds in the presence of a modular and removable triazolyldimethylmethyl (TAM) auxiliary, whose structure can be varied through 1,3-dipolar azide-alkyne cycloadditions.
Remote C-H bond functionalization reveals the distance-dependent isotope effect
Li, Jiao-Jie,Giri, Ramesh,Yu, Jin-Quan
, p. 6979 - 6987 (2008/09/21)
Iodination of remote aryl C-H bonds has been achieved using palladium acetate as the catalyst and iodoacetate (IOAc) as the oxidant. Systematic kinetic isotope studies imply a mechanistic regime shift as the number of bonds separating the directing heteroatom and the target C-H bond increases. Both isotope and electronic effects observed in remote C-H bond activation are consistent with an electrophilic palladation pathway in which the initial palladation is slower than the C-H bond cleavage.
