3092-20-4Relevant academic research and scientific papers
A practical and reusable catalyst for the synthesis of donor-acceptor cyclopropane
Zhang, Yanqun,Jin, Manyu,Wu, Cunqi,Zhao, Yongxia,Zhou, Hua,Xu, Jingwei
, p. 5 - 9 (2018)
Herein, a convenient, recyclable and inexpensive Cu-based catalytic system is developed for the synthesis of donor-acceptor (D-A) cyclopropane via the cycloaddition of styrene derivatives with diethyl bromomalonate. A core-shell catalyst of Fe3
Copper(II) Halide Catalyzed Cyclopropanation of Olefins Involving Dehydrobromination of Bromomalonic Ester by Amine
Kawabata, Nariyoshi,Yanao, Shinji,Yoshida, Jun-ichi
, p. 2687 - 2688 (1982)
The reaction of olefins with bromomalonic ester and 1,8-diazabicycloundec-7-ene (DBU) proceeded in the presence of a catalytic amount of copper(II) halide to give 1,1-bis(alkoxycarbonyl)cyclopropane derivatives.DBU was converted into DBU-hydrobromi
Synthesis of Thio-/Selenopyrrolines via SnCl4-Catalyzed (3+2)-Cycloadditions of Donor-Acceptor Cyclopropanes with Thio-/Selenocyanates
Ali, Shamsad,Goswami, Avijit,Kalaramna, Pratibha,Singh, Prasoon Raj
supporting information, p. 4683 - 4689 (2021/09/10)
A straightforward protocol has been developed to access thio-/selenopyrrolines through a (3+2)-cycloaddition of aryl thio-/selenocyanates with donor-acceptor cyclopropanes (DACs) in the presence of SnCl4 as a Lewis acid catalyst. Further, good chemoselectivity was observed when DACs were treated with 3-cyano phenyl thiocyanate. These results suggest that thiocyanate is more reactive than nitrile moiety in such (3+2)-cycloaddition reactions.
(3 + 2)-Cycloaddition of Donor-Acceptor Cyclopropanes with Selenocyanate: Synthesis of Dihydroselenophenes and Selenophenes
Jacob, Anu,Jones, Peter G.,Werz, Daniel B.
supporting information, (2020/11/13)
We present a Lewis-acid-catalyzed (3 + 2)-cycloaddition of donor-acceptor cyclopropanes and selenocyanate (as its tetramethylammonium salt) for the synthesis of dihydroselenophenes. The transformation proceeded with moderate to excellent yields and showed a high functional group tolerance. Further oxidation using DDQ delivered selenophenes.
Accessing dihydro-1,2-oxazine via cloke-wilson-type annulation of cyclopropyl carbonyls: application toward the diastereoselective synthesis of pyrrolo[1,2- b][1,2]oxazine
Banerjee, Prabal,Kumar, Pankaj,Kumar, Rakesh
supporting information, p. 6535 - 6550 (2020/06/09)
A convenient additive-free synthesis of dihydro-4H-1,2-oxazines via a Cloke-Wilson-type ring expansion of the aryl-substituted cyclopropane carbaldehydes with the hydroxylamine salt is introduced. Comparatively less active cyclopropyl ketones also follow a similar protocol if supplemented by catalytic p-toluene sulfonic acid monohydrate. The transformation is performed in an open-to-air flask as it shows negligible sensitivity toward air/moisture. Dihydro-4H-1,2-oxazines when subjected to cycloaddition with the cyclopropane diester afford a trouble-free formulation of the valued hexahydro-2H-pyrrolo[1,2-b][1,2]oxazine derivatives. A cascade one-pot variant of this two-step strategy offers a comparable overall yield of the final product.
Stereospecific copper(II)-catalyzed tandem ring opening/oxidative alkylation of donor-acceptor cyclopropanes with hydrazones: Synthesis of tetrahydropyridazines
Mishra, Manmath,De, Pinaki Bhusan,Pradhan, Sourav,Punniyamurthy, Tharmalingam
, p. 10901 - 10910 (2019/09/13)
Aerobic copper(II)-catalyzed tandem ring opening and oxidative C-H alkylation of donor-acceptor cyclopropanes with bisaryl hydrazones is accomplished to produce tetrahydropyridazines, in which copper(II) plays dual role as a Lewis acid as well as redox catalyst. The reaction is stereospecific, and optically active cyclopropanes can be reacted with high optical purities (89-98% enantiomeric excess). The substrate scope, functional group tolerance, dual role of the copper(II) catalyst, and the use of air as an oxidant are the important practical features. A product bearing a 3-bromoaryl group can be subjected to Pd-catalyzed Suzuki coupling with boronic acid in high yield.
Formal Insertion of Thioketenes into Donor-Acceptor Cyclopropanes by Lewis Acid Catalysis
Augustin, André U.,Busse, Marius,Jones, Peter G.,Werz, Daniel B.
supporting information, p. 820 - 823 (2018/02/10)
Donor-acceptor cyclopropanes were reacted under Lewis acid catalysis with 3-thioxocyclobutanones as surrogates for disubstituted thioketenes. A broad scope of 2-substituted tetrahydrothiophenes with a semicyclic double bond was obtained under mild conditions with high functional group tolerance and in excellent yield. A sequence of a formal [3 + 2]-cycloaddition followed by the subsequent release of disubstituted ketene is postulated as the mechanism.
Lewis Acid Catalyzed Annulation of Cyclopropane Carbaldehydes and Aryl Hydrazines: Construction of Tetrahydropyridazines and Application Toward a One-Pot Synthesis of Hexahydropyrrolo[1,2- b]pyridazines
Dey, Raghunath,Kumar, Pankaj,Banerjee, Prabal
, p. 5438 - 5449 (2018/05/28)
In this report, a facile synthesis of tetrahydropyridazines via a Lewis acid catalyzed annulation reaction of cyclopropane carbaldehydes and aryl hydrazines has been demonstrated. Moreover, the generated tetrahydropyridazine further participated in a cycloaddition reaction with donor-acceptor cyclopropanes to furnish hexahydropyrrolo[1,2-b]pyridazines. We also performed these two steps in one pot in a consecutive manner. In addition, a monodecarboxylation reaction of hexahydropyrrolo[1,2-b]pyridazine was achieved with a good yield.
Nucleophilic Ring Opening of Donor-Acceptor Cyclopropanes Catalyzed by a Br?nsted Acid in Hexafluoroisopropanol
Richmond, Edward,Vukovi?, Vuk D.,Moran, Joseph
supporting information, p. 574 - 577 (2018/02/10)
A general, Br?nsted acid catalyzed method for the room temperature, nucleophilic ring opening of donor-acceptor cyclopropanes in fluorinated alcohol solvent, HFIP, is described. Salient features of this method include an expanded cyclopropane scope, including those bearing single keto-acceptor groups and those bearing electron-deficient aryl groups. Notably, the catalytic system proved amenable to a wide range of nucleophiles including arenes, indoles, azides, diketones, and alcohols.
Synthesis of Indenopyridine Derivatives via MgI2-Promoted [2+4] Cycloaddition Reaction of In-situ Generated 2-Styrylmalonate from Donor-Acceptor Cyclopropanes and Chalconimines
Verma, Kamal,Banerjee, Prabal
supporting information, p. 3687 - 3692 (2018/10/15)
An unexpected MgI2-promoted [2+4] cycloaddition reaction of in-situ generated 2-styrylmalonate from donor-acceptor cyclopropanes with chalconimines to synthesize highly substituted indenopyridine derivatives under the mild reaction conditions h
