851293-09-9Relevant academic research and scientific papers
(3+2)-Cycloaddition of Donor-Acceptor Cyclopropanes with Thiocyanate: A Facile and Efficient Synthesis of 2-Amino-4,5-dihydrothiophenes
Jacob, Anu,Barkawitz, Philip,Andreev, Ivan A.,Ratmanova, Nina K.,Trushkov, Igor V.,Werz, Daniel B.
supporting information, p. 901 - 904 (2021/03/17)
An easy and efficient route to obtain 2-amino-4,5-dihydrothiophenes is presented. A formal (3+2)-cycloaddition of donor-acceptor cyclopropanes and ammonium thiocyanate catalyzed by Yb(OTf) 3delivers the desired products in good to excellent yields. A broad range of functional groups is tolerated during this process.
(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.
An Expeditious Route to trans-Configured Tetrahydrothiophenes Enabled by Fe(OTf)3-Catalyzed [3+2] Cycloaddition of Donor–Acceptor Cyclopropanes with Thionoesters
Matsumoto, Yohei,Nakatake, Daiki,Yazaki, Ryo,Ohshima, Takashi
supporting information, p. 6062 - 6066 (2018/03/28)
A synthetic route to trans-configured tetrahydrothiophenes (THTs) through Fe(OTf)3-promoted [3+2] cycloaddition of donor–acceptor cyclopropanes with thionoesters was developed. The cycloaddition proceeded in high yield with high diastereoselectivity, affording transient α-alkoxy THTs. Not only aromatic and aliphatic thionoesters, but also thionolactone were applicable to the present iron catalysis. Further transformation of the S,O-ketal functionality of the product was achieved in a highly trans diastereoselective manner. Moreover, the utility of our methodology was clearly demonstrated by the synthesis of enantioenriched trans-configured THTs.
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.
Cascade One-Pot Synthesis of Indanone-Fused Cyclopentanes from the Reaction of Donor-Acceptor Cyclopropanes and Enynals via a Sequential Hydrolysis/Knoevenagel Condensation/[3+2] Cycloaddition
Zhang, Jiantao,Jiang, Huanfeng,Zhu, Shifa
, p. 2924 - 2930 (2017/09/08)
A cascade reaction of donor-acceptor cyclopropanes with enynals to construct indanone-fused cyclopentanes via a sequential hydrolysis/Knoevenagel condensation/[3+2] cycloaddition is reported. The desired indanone-fused cyclopentanes were obtained in good yields. This method features mild reaction conditions and broad substrate scope, which render it very appealing to chemists for the synthesis of complex molecules containing an indanone-fused cyclopentane moiety. Moreover, the products could be further converted into compounds with different functional groups through the well-known transformations. (Figure presented.).
Scandium(III) Trifluoromethanesulfonate Catalyzed Selective Reactions of Donor–Acceptor Cyclopropanes with 1,1-Diphenylethanols: An Approach to Polysubstituted Olefins
Zhu, Xiaoyan,Hong, Gang,Hu, Chen,Wu, Shengying,Wang, Limin
, p. 1547 - 1551 (2017/04/01)
An unexpected synthetic approach to polysubstituted olefins through the scandium(III) trifluoromethanesulfonate catalyzed ring-opening reaction of donor–acceptor cyclopropanes with 1,1-diphenylethanols was developed. The reactions, which are experimentally easy to handle, feature tolerance of various functional groups and mild reaction conditions. On the basis of experimental evidence, a plausible mechanism was also proposed.
Regioselective Hydrogenolysis of Donor-Acceptor Cyclopropanes with Zn-AcOH Reductive System
Ivanov, Konstantin L.,Villemson, Elena V.,Latyshev, Gennadij V.,Bezzubov, Stanislav I.,Majouga, Alexander G.,Melnikov, Mikhail Ya.,Budynina, Ekaterina M.
, p. 9537 - 9549 (2017/09/23)
A convenient low-cost method for regioselective ring-opening of donor-acceptor cyclopropanes with the Zn-AcOH reductive system was developed. The general character of the method was displayed via efficient reduction of a representative series of 2-(het)arylcyclopropane-1,1-diesters as well as donor-acceptor cyclopropanes with other types of electron-withdrawing activating groups. This method opens a rapid access to γ-substituted propyl-1,1-diesters, ketoesters, cyanoesters, cyanoamides, dinitriles, etc., many of which are not readily accessible with alternative methods. The utility of the synthesized compounds was demonstrated by transforming them into valuable acyclic and cyclic compounds (including pharmacologically relevant carbazoles, δ-lactams, and oxindole derivatives).
A facile formal [2+1] cycloaddition of styrenes with alpha-bromocarbonyls catalyzed by copper: Efficient synthesis of donor-acceptor cyclopropanes
Nishikata, Takashi,Noda, Yushi,Fujimoto, Ryo,Ishikawa, Shingo
supporting information, p. 12843 - 12846 (2015/08/18)
Reactions of 2-bromoesters and styrenes underwent a [2+1] cycloaddition reaction, i.e., cyclopropanation, to produce donor-acceptor (D-A) cyclopropanes through a radical addition-ring closure process. In this reaction, the combination of copper(ii) comple
A new type of donor-acceptor cyclopropane reactivity: The generation of formal 1,2- and 1,4-dipoles
Novikov, Roman A.,Tarasova, Anna V.,Korolev, Victor A.,Timofeev, Vladimir P.,Tomilov, Yury V.
, p. 3187 - 3191 (2014/04/03)
A new type of donor-acceptor cyclopropane reactivity has been discovered. On treatment with anhydrous GaCl3, they react as sources of even-numbered 1,2- and 1,4-dipoles instead of the classical odd-numbered 1,3-dipoles due to migration of positive charge from the benzyl center. This type of reactivity has been demonstrated for new reactions, namely, cyclodimerizations of donor-acceptor cyclopropanes that occur as [2+2]-, [3+2]-, [4+2]-, [5+2]-, [4+3]-, and [5+4]-annulations. The [4+2]-annulation of 2-arylcyclopropane-1,1-dicarboxylates to give polysubstituted 2-aryltetralins has been developed in a preparative version that provides exceedingly high regio- and diastereoselectivity and high yields. The strategy for selective hetero-combination of donor-acceptor cyclopropanes was also been developed. The mechanisms of the discovered reactions involving the formation of a comparatively stable 1,2-ylide intermediate have been studied. Old ring, new reactivity: A new type of donor-acceptor cyclopropane reactivity has been discovered. On treatment with anhydrous GaCl3, they react as sources of even-numbered 1,2- and 1,4-dipoles instead of the classical odd-numbered 1,3-dipoles owing to the migration of positive charge from the benzyl center.
TiCl4 promoted formal [3 + 3] cycloaddition of cyclopropane 1,1-diesters with azides: Synthesis of highly functionalized triazinines and azetidines
Zhang, Huan-Huan,Luo, Yong-Chun,Wang, Hua-Peng,Chen, Wei,Xu, Peng-Fei
, p. 4896 - 4899 (2015/04/27)
A TiCl4 promoted formal [3 + 3] cycloaddition of cyclopropane 1,1-diesters with azides has been developed for the synthesis of highly functionalized triazinines. Both stoichiometric and substoichiometric versions of this reaction were accomplished dependent on the choice of solvent. It is noteworthy that the corresponding products could be easily converted to biologically important azetidines by simple thermolysis.
