Rhodium-Catalyzed Cyclopropanation of Alkenes with Dimethyl Diazomalonate
作者:Francisco González-Bobes、Michaël D. B. Fenster、Susanne Kiau、Laxma Kolla、Sergei Kolotuchin、Maxime Soumeillant
DOI:10.1002/adsc.200800027
日期:2008.4.7
α′-tetramethyl-1,3-benzenedipropanoate] to catalyze the cyclopropanation of a wide range of alkenes with malonate-derived carbenoids under mild reaction conditions is reported in this communication. The experimental protocol is remarkably simple, uses readily accessible and stable dimethyldiazomalonate with very low catalyst loading. More importantly, the alkene is employed as a limiting reagent.
Lewis Acid Catalyzed Nucleophilic Ring Opening and 1,3-Bisfunctionalization of Donor–Acceptor Cyclopropanes with Hydroperoxides: Access to Highly Functionalized Peroxy/(α-Heteroatom Substituted)Peroxy Compounds
作者:Kuldeep Singh、Tishyasoumya Bera、Vandana Jaiswal、Subrata Biswas、Biplab Mondal、Dinabandhu Das、Jaideep Saha
DOI:10.1021/acs.joc.8b02561
日期:2019.1.18
catalyzed ring opening reaction of Donor–Acceptor (D–A) cyclopropanes with alkyl hydroperoxides is reported to furnish various peroxycarbonyls and 1,3-haloperoxygenated compounds in good to excellent yields. This method adds another instance to scarcely reported noncyclilizing 1,3-bisfunctionalization of D–A cyclopropanes with two different functional groups and relies on the dual role of peroxide as nucleophile
Kinetic Studies of Donor-Acceptor Cyclopropanes: The Influence of Structural and Electronic Properties on the Reactivity
作者:Alexander Kreft、Alexander Lücht、Jörg Grunenberg、Peter G. Jones、Daniel B. Werz
DOI:10.1002/anie.201812880
日期:2019.2.11
substituent parameter σ. The obtained rate constants from the (3+2) cycloadditions correlate well with data from additionally studied (3+n) cycloadditions with a nitrone (n=3) and an isobenzofuran (n=4). A comparison of the kinetic data with the bond lengths in the cyclopropane (obtained by X‐ray diffraction and computation), or the 1H and 13C NMR shifts, revealed no correlation. However, the computed relaxed
α-position of acetophenone derivatives to donor–acceptorcyclopropanes, were synthesized in two steps via first ringopening of donor–acceptorcyclopropanes with acyclic 1,3-diketones followed by DBU catalyzed retro-Claisen-type C–C bond cleavage reactions. In the first step, acyclic 1,3-diketones selectively worked as C-nucleophiles to add to donor–acceptorcyclopropanes. In the second step, the alkyl ketone
1,3-Cyclohexandione derived cyclic ketals and thiol ketals were used as O- and S-nucleophiles, respectively, for the ring opening of donor–acceptor cyclopropanes catalyzed by Cu(OTf)2 and a series of functionalized alkylene glycol diethers and dithiol diethers were obtained in good to high yields under mild conditions.