An Expeditious Route to<i>trans</i>-Configured Tetrahydrothiophenes Enabled by Fe(OTf)<sub>3</sub>-Catalyzed [3+2] Cycloaddition of Donor-Acceptor Cyclopropanes with Thionoesters
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
Formal Insertion of Thioketenes into Donor–Acceptor Cyclopropanes by Lewis Acid Catalysis
作者:André U. Augustin、Marius Busse、Peter G. Jones、Daniel B. Werz
DOI:10.1021/acs.orglett.7b03961
日期:2018.2.2
Donor–acceptorcyclopropanes 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
(3+2)-Cycloaddition of Donor–Acceptor Cyclopropanes with Thiocyanate: A Facile and Efficient Synthesis of 2-Amino-4,5-dihydrothiophenes
作者:Daniel B. Werz、Anu Jacob、Philip Barkawitz、Ivan A. Andreev、Nina K. Ratmanova、Igor V. Trushkov
DOI:10.1055/a-1385-2385
日期:2021.6
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)3 delivers the desired products in good to excellent yields. A broad range of functional groups is tolerated during this process.
Ring-Opening 1,3-Dichlorination of Donor–Acceptor Cyclopropanes by Iodobenzene Dichloride
作者:Lennart K. B. Garve、Philip Barkawitz、Peter G. Jones、Daniel B. Werz
DOI:10.1021/ol5029139
日期:2014.11.7
Donor–acceptor cyclopropanes are reacted with iodobenzenedichloride to afford ring-opened products bearing chlorine atoms in the 1- and 3-positions, adjacent to the donor and acceptor groups. A variety of different donors (e.g., alkyl, aryl, N, and O) and acceptor moieties (e.g., ketones, diesters, and dinitriles) are used.
Catalytic [3+2] Annulation of Aminocyclopropanes for the Enantiospecific Synthesis of Cyclopentylamines
作者:Florian de Nanteuil、Jérôme Waser
DOI:10.1002/anie.201106255
日期:2011.12.9
With nitrogen too: The first catalytic [3+2] annulation of aminocyclopropanes with enol ethers is reported (see scheme; Phth=phthaloyl). The reaction worked with easily accessible phthalimidocyclopropanes using 5 mol % of SnCl4 in nearly quantitative yields. Polysubstituted cyclopentylamines, which are often present in bioactive compounds, were obtained with high diastereoselectivity and enantiospecificity