The regioselectivity of nitrone and nitrile oxide cycloadditions to alkylidenecyclopropanes
作者:Alberto Brandi、Franca M. Cordero、Francesco De Sarlo、Remo Gandolfi、Andrea Rastelli、Marisa Bagatti
DOI:10.1016/0040-4020(92)85008-3
日期:1992.1
The 1,3-dipolarcycloaddition of nitrile oxides and a nitrone to alkylidencyclopropanes 1–5,used as model for methylenecyclopropanes substituted with arylgroup (1), electron-releasing groups (2 and 3) and electron-attracting groups (4 and 5) is reported. The cycloaddition to alkylidenecyclopropanes 1–3 gives prevalently or exclusively adducts bearing the cyclopropane ring on the C4 position of the
Regioselectivity in the 1,3-dipolar cycloaddition of nitrile oxides to alkylidenecyclopropanes.
作者:Alberto Brandi、Silvio Carli、Antonio Guarna、Francesco De Sarlo
DOI:10.1016/s0040-4039(00)96402-5
日期:1987.1
The 1,3-dipolarcycloaddition of nitrileoxides to methylenecyclopropanes substituted on the exocyclic double bond gives prevalently or exclusively 4-spirocyclopropane isoxazolines when the substituent is arylic or alkylic group, 5-spirocyclopropane isoxazolines when the substituent is an electron-withdrawing group. Adducts 16 and 17 selectively rearrange photochemically to the enaminoenone 19.
The First Facile Synthesis of Some 1,2a,3,8b-Tetrahydro-2H-Cyclobuta[c] Chromenes Through Intramolecular Alkylation of an Aromatic Ring by a Cyclobutanone
作者:Angela M. Bernard、Costantino Floris、Angelo Frongia、Pier P. Piras
DOI:10.1055/s-2002-25355
日期:——
Starting from cyclobutanones several new chromenes containing a cyclobutane ring are prepared. Ring fission of these derivatives gives easy access to functionalized 3-isoflavenes.
Cobalt-Catalyzed Hydrocyanation of Methylenecyclopropanes to Homoallylic Nitriles
作者:Mingdong Jiao、Xianjie Fang
DOI:10.1021/acs.orglett.2c03726
日期:2022.12.9
We describe herein a novel synthesis of various homoallylic nitriles via cobalt-catalyzed hydrocyanation of methylenecyclopropanes. Excellent selectivity, mild reaction conditions, good functional group compatibility, gram-scale reaction, and product transformations demonstrate the power of this protocol. This extraordinary selectivity can probably be attributed to the stronger aptitude of the alkyl–cobalt