334474-15-6Relevant academic research and scientific papers
An Approach to Five-Membered Lactams from Aliphatic Amides and Terminal Acetylenes by Nickel Catalysis
Lin, Cong,Zhang, Jitan,Chen, Zhengkai,Liu, Yue,Liu, Zhanxiang,Zhang, Yuhong
, p. 1778 - 1793 (2016)
A nickel-catalyzed facile synthesis of structurally diverse five-membered lactams from aliphatic amides and terminal acetylenes with the assistance of an 8-aminoquinolyl auxiliary has been achieved. A broad range of terminal acetylenes and aliphatic amide
Copper-Catalyzed Modular Access to N-Fused Polycyclic Indoles and 5-Aroyl-pyrrol-2-ones via Intramolecular N—H/C—H Annulation with Alkynes: Scope and Mechanism Probes
Liu, Yan-Hua,Song, Hong,Zhang, Chi,Liu, Yue-Jin,Shi, Bing-Feng
, p. 1545 - 1552 (2020/09/09)
Copper-catalyzed intramolecular N—H/C—H annulation with alkynes has been developed. A variety of densely functionalized heterocycles, such as pyrrolo[1,2-a]indoles, indolo[1,2-c]quinazolin-2-ones, oxazolo[3,4-a]indoles, and imidazo[1,5-a]indoles, were synthesized in an atom- and step-economical manner, owing to the high modularized feature of aniline moiety, the linker moiety, as well as the alkyne moiety. By simply changing the oxidant from di-tert-butyl peroxide (DTBP) to 2,2,6,6-tetramethylpiperidine-1-oxyl (TEMPO), the reaction could readily be transformed to the aminooxygenation pathway, which grabs one oxygen atom from the TEMPO to generate 5-aroyl-pyrrol-2-ones. Mechanistic experiments indicate that vinyl radical is involved in this reaction and an amidyl-radical-initiated radical cascade might be responsible for this transformation.
Stoichiometric and Catalytic C?C and C?H Bond Formation with B(C6F5)3 via Cationic Intermediates
Soltani, Yashar,Wilkins, Lewis C.,Melen, Rebecca L.
, p. 11995 - 11999 (2017/09/20)
This work showcases a new catalytic cyclization reaction using a highly Lewis acidic borane with concomitant C?H or C?C bond formation. The activation of alkyne-containing substrates with B(C6F5)3 enabled the first catalytic intramolecular cyclizations of carboxylic acid substrates using this Lewis acid. In addition, intramolecular cyclizations of esters enable C?C bond formation as catalytic B(C6F5)3 can be used to effect formal 1,5-alkyl migrations from the ester functional groups to unsaturated carbon–carbon frameworks. This metal-free method was used for the catalytic formation of complex dihydropyrones and isocoumarins in very good yields under relatively mild conditions with excellent atom efficiency.
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.
Cu-Catalyzed Alkynylation of Unactivated C(sp3)-X Bonds with Terminal Alkynes through Directing Strategy
Luo, Fei-Xian,Xu, Xing,Wang, Ding,Cao, Zhi-Chao,Zhang, Yun-Fei,Shi, Zhang-Jie
, p. 2040 - 2043 (2016/06/01)
In this letter, we report an efficient and concise protocol for Cu-catalyzed cross-coupling of unactivated alkyl halides/peusudohalides with terminal alkynes to afford internal alkynes with the assistance of various amides as directing groups. Different alkyl halides/pseudohalides exhibited excellent reactivities, and the inactivated alkyl chlorides and sulfonates showed better reactivity than bromides/iodides. This is the first successful example to apply alkyl chlorides and sulfonates directly in cross-coupling with terminal alkynes in the absence of any additives. A Cu catalyst was found to be more effective than other transition metal catalysts. This reaction also exhibited a broad substrate scope with respect to terminal alkynes.
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.
Bismuth-catalyzed intramolecular carbo-oxycarbonylation of 3-alkynyl esters
Komeyama, Kimihiro,Takahashi, Keita,Takaki, Ken
supporting information; experimental part, p. 5119 - 5122 (2009/05/30)
(Chemical Equation Presented) Borderline metal complexes, especially Bi(OTf)3, efficiently catalyze the carbo-oxycarbonylation of alkynyl esters to form multisubstituted lactones in moderate to high yields.
Gold(I)-catalyzed oxidative rearrangements
Witham, Cole A.,Mauleon, Pablo,Shapiro, Nathan D.,Sherry, Benjamin D.,Toste, F. Dean
, p. 5838 - 5839 (2008/02/12)
A series of gold(I)-catalyzed oxidative rearrangement reactions of alkynes using sulfoxides as stoichiometric oxidants are reported. The reactions are postulated to proceed through intermolecular oxygen atom transfer from the sulfoxide to gold(I)-carbenoi
Studies in chlorin chemistry. II. A versatile synthesis of dihydrodipyrrins
O'Neal, William G.,Roberts, William P.,Ghosh, Indranath,Jacobi, Peter A.
, p. 7243 - 7251 (2007/10/03)
Dihydrodipyrrins are key building blocks for the synthesis of hydroporphyrins, many of which have important biological activity. The title compounds were prepared in stereo- and regioselective fashion by a three-step sequence consisting of (1) Pd(0)-catal
