54835-91-5Relevant academic research and scientific papers
Cooperative NHC/Photoredox Catalyzed Ring-Opening of Aryl Cyclopropanes to 1-Aroyloxylated-3-Acylated Alkanes
Daniliuc, Constantin G.,Studer, Armido,Zuo, Zhijun
, p. 25252 - 25257 (2021/10/29)
Cyclopropanes are an important class of building blocks in organic synthesis. Herein, a ring-opening/arylcarboxylation/acylation cascade reaction for the 1,3-difunctionalization of aryl cyclopropanes enabled by cooperative NHC and organophotoredox catalysis is reported. The cascade works on monosubstituted cyclopropanes that are in contrast to the heavily investigated donor–acceptor cyclopropanes more challenging to be difunctionalized. The key step is a radical/radical cross coupling of a benzylic radical generated in the photoredox catalysis cycle with a ketyl radical from the NHC catalysis cycle. The transformation features metal-free reaction conditions and tolerates a diverse range of functionalities.
Kinetic Enzymatic Resolution of Cyclopropane Derivatives
Pietruszka, Joerg,Rieche, Anja C. M.,Wilhelm, Thorsten,Witt, Andreas
, p. 1273 - 1286 (2007/10/03)
The kinetic enzymatic resolution of various cyclopropane derivatives was systematically investigated. The study focused on synthetically useful cyclopropylmethanols (e.g., 18a/j or 19a/j) as well as some rarely investigated cyclopropanols (e.g., 24/25 or 27). The combination of enantioselective catalytic or diastereoselective synthesis of enantiomerically enriched compounds with enzymatic approaches ultimately led to the most convenient route to enantiomerically pure starting materials. Again, this was especially proven for the synthesis of cyclopropanols 18a/j and 19a/j. Key to the successful investigation was to rigorously establish an analytical tool for the analysis of enantiomeric composition of reaction mixtures.
ARYLCYCLOPROPANE PHOTOCHEMISTRY. UNUSUAL AROMATIC SUBSTITUENT EFFECTS ON THE PHOTOCHEMICAL REARRANGEMENT OF (2-ARYLCYCLOPROPYL)METHYL ACETATES TO 1-ARYLHOMOALLYL ACETATES.
Hixson,Franke,Gere,Xing
, p. 3601 - 3610 (2007/10/02)
Irradiation of trans(2-arylcyclopropyl)methyl acetates a 4-butenyl-1-arylacetate (7a,b,d-h) via an ionic mechanism from the singlet state. Similar rearrangements occurred with exo-(1,1a,6,6a-tetrahydrocycloprop left bracket a right bracket inden-1-yl)methyl acetate and the 4-cyano derivative. Excited state reaction rate constants were determined from reactant fluorescence lifetimes and product quantum yields. It is concluded that the rate-determining step involves conversion of the initially formed aromatic excited state to a reactive cyclopropane excited state and that cyclopropane to aromatic ring charge transfer enhances this process.
