Lewis Acid Triggered Vinylcyclopropane–Cyclopentene Rearrangement
作者:Olga A. Ivanova、Alexey O. Chagarovskiy、Alexey N. Shumsky、Vasiliy D. Krasnobrov、Irina I. Levina、Igor V. Trushkov
DOI:10.1021/acs.joc.7b02351
日期:2018.1.19
donor–acceptor cyclopropanes, containing an alkenyl moiety and diverse electron-withdrawinggroup(s) at the adjacent positions, into substituted cyclopentenes. We have found that 1,1,2-trisubstituted cyclopent-3-enes were exclusively obtained in yield of 51–99% when cyclopropanes with a 2-substituted alkenyl group as a donor underwent isomerization. For cyclopropanes bearing a trisubstituted alkenyl group either
<i>cis</i>-Selective, Enantiospecific Addition of Donor–Acceptor Cyclopropanes to Activated Alkenes: An Iodination/Michael-Cyclization Cascade
作者:Nils L. Ahlburg、Peter G. Jones、Daniel B. Werz
DOI:10.1021/acs.orglett.0c02210
日期:2020.8.21
biologically interesting scaffolds, including barbiturates and isoxazolones. Mechanistic investigations were undertaken to explain the unusual diastereoselectivity and enantiospecificity; these suggest an iodination/Michael-cyclization cascade.
Tandem Cyclopropane Ring-Opening/Conia-ene Reactions of 2-Alkynyl Indoles: A [3 + 3] Annulative Route to Tetrahydrocarbazoles
作者:Huck K. Grover、Terry P. Lebold、Michael A. Kerr
DOI:10.1021/ol102627e
日期:2011.1.21
A Zn(NTf2)2catalyzed tandem reaction consisting of a nucelophilic ringopening of 1,1-cyclopropanediesters by 2-alkynyl indoles followed by a Conia-ene ring closure results in the efficient one-step synthesis of tetrahydrocarbazoles. The adducts may be further elaborated to carbazoles.
[Yb(OTf)3]‐catalyzed diastereoselective cascade reaction of m‐N,N‐dimethylaminophenyl α,β‐unsaturated carbonyls with cyclopropane 1,1‐diesters under mild reaction conditions afforded highly substituted cis‐ and trans‐tetralins. The reaction of m‐N,N‐dimethylaminophenyl α,β‐unsaturated ketones with cyclopropane 1,1‐diesters provided tetralins with a trans orientation of the 1,4‐substitutents on the cyclohexyl ring;
diastereo- and enantioselective BOX/Cu(II)-catalyzed C2,C3-cyclopentannulation of indoles with donor-acceptor cyclopropanes has been developed on the basis of asymmetric formal [3 + 2] cycloaddition of indoles. This reaction provides rapid and facile access to a series of enantioenriched cyclopenta-fused indoline products and can be further extended to the construction of tetracyclic pyrroloindolines. The synthetic