864682-51-9Relevant academic research and scientific papers
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
supporting information, 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.
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.
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 (2016/06/09)
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
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.
Rhodium-catalyzed arylative cyclization for the enantioselective synthesis of (trifluoromethyl)cyclobutanols
Johnson, Thomas,Choo, Ken-Loon,Lautens, Mark
supporting information, p. 14194 - 14197 (2015/02/19)
A rhodium-catalyzed cyclization of 1-(trifluoro-methyl)-4-alkyn-1-ones with arylboronic acids is described to yield a novel class of small rings: (trifluoromethyl)cyclobutanols bearing an exocyclic double bond. The use of a rhodium/chiral diene complex allowed the reaction to proceed under mild conditions, often with high enantioselectivity. An X-ray crystal structure was obtained confirming the formation of the four-membered ring products.
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
