36748-92-2Relevant academic research and scientific papers
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)
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.
Copper(II)-mediated intermolecular amination of inert C(sp3)[sbnd]H bonds with simple alkylamines to construct α,α-disubstituted β-amino acid derivatives
Wang, Chunxia,Yang, Yudong
supporting information, p. 935 - 940 (2017/02/18)
Disclosed herein is a copper(II)-mediated chelation-assisted intermolecular amination of inert C(sp3)[sbnd]H bonds using simple alkylamines as the amino source. A straightforward and step-economic alternative to α,α-disubstituted β-amino acid derivatives is provided consequently. This reaction features good functional group tolerance and relatively broad substrate scope. Furthermore, a coupling product between morpholine and radical inhibitor 2,6-di-tert-butyl-p-cresol (BHT) was isolated, indicating that a single electron transfer (SET) process might be involved in this transformation.
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
supporting information, 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 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.
Palladium(0)/PAr3-catalyzed intermolecular amination of C(sp3)-H bonds: Synthesis of β-amino acids
He, Jian,Shigenari, Toshihiko,Yu, Jin-Quan
supporting information, p. 6545 - 6549 (2015/06/08)
An intermolecular C(sp3)-H amination using a Pd0/PAr3 catalyst was developed. The reaction begins with oxidative addition of R2N-OBz to a Pd0/PAr3 catalyst and subsequent cleavage of a C(sp3)-H bond by the generated Pd-NR2 intermediate. The catalytic cycle proceeds without the need for external oxidants in a similar manner to the extensively studied palladium(0)-catalyzed C-H arylation reactions. The electron-deficient triarylphosphine ligand is crucial for this C(sp3)-H amination reaction to occur.
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.
