Michael Addition Initiated Carbocyclization Sequences with Nitroolefins for the Stereoselective Synthesis of Functionalized Heterocyclic and Carbocyclic Systems
The synthesis of various heterocycles and carbocycles (tetrahydrofurans, pyrrolidines, cyclopentanes) has been achieved by using new and efficient ionic addition/cyclization sequences. Nitroolefins play an important role in the Michael addition induced ring‐closing reactions (MIRC) reported in the present article, with various substituted alcohols, amines, Grignard reactants, or malonate derivatives
One-Pot Michael Addition/Intramolecular Carbocyclization of Dimethyl Propargylmalonate with Nitroalkenes: A New Stereoselective [3+2] Annulation to 1-Nitro 2-Methylenecyclopentanes
A new one-pot diastereoselective synthesis of nitro methylenecyclopentanes 3a-g has been achieved by [3+2] annulation of dimethyl propargylmalonate 2 and nitroalkenes la-g in the presence of Triton B.
1,3-Dipolar Cycloadditions of Diazomethane to Chiral Electron-Deficient Olefins: The Origin of the π-Facial Diastereoselection
作者:Elena Muray、Angel Alvarez-Larena、Joan F. Piniella、Vicenç Branchadell、Rosa M. Ortuño
DOI:10.1021/jo991227j
日期:2000.1.1
The stereochemical outcome of diazomethane cycloadditions to several chiral electron-deficientolefins has been investigated in order to establish the origin of the pi-facial diastereoselection. Nitro olefins, vinyl sulfones, enoates, and 2-amino enoates have been used for such a purpose. These substrates have been prepared from D-glyceraldehyde acetonide through Wittig-type condensations and present
Diastereoselective conjugate addition and cyclopropanation reactions with nitroalkenes derived from (R)-2,3-isopropylidene glyceraldehyde
作者:Guido Galley、Jan Hübner、Sven Anklam、Peter G Jones、Michael Pätzel
DOI:10.1016/0040-4039(96)01374-3
日期:1996.8
In the reactions of functionalized organometallics and of cyclopropanation reagents with chiral nitroalkenes 3 the conjugateaddition proceeded with modest to high diastereoselectivity depending on the metal and the substituent R. X-ray analyses showed the nitrocyclopropanes 6, formed with high stereoselectivity, to be syn-derivatives.
Stereoselective aza-MIRC reactions on optically active (E)-nitro alkenes
作者:Stefania Fioravanti、Fabio Marchetti、Lucio Pellacani、Luca Ranieri、Paolo A. Tardella
DOI:10.1016/j.tetasy.2007.12.007
日期:2008.2
Opticallyactive (E)-nitro alkenes carrying a 1,3-dioxolane or 1,3-oxazolidine residue undergo stereoselective aza-MIRC reactions, leading to the synthesis of the corresponding chiral nitro aziridines in high yields and with good diastereoselectivity. Interestingly, the stereochemical outcome of the aziridination reactions was strongly influenced by the chiral residue considered, giving stereoisomers