An Efficient, One-Pot Synthesis of Isomeric Ellipticine Derivatives through Intramolecular Imino-Diels−Alder Reaction
作者:Vikram Gaddam、Rajagopal Nagarajan
DOI:10.1021/ol800497u
日期:2008.5.1
New analogues of isomeric ellipticine derivatives fused with biologically important pyrroloindole or chromene moiety have been synthesized by utilizing an intramolecular imino Diels-Alder reaction in a single step.
A highly diastereo- and enantioselective intramolecular Alder-ene reaction with an alkene as the enophile has been developed by using a chiral N,N′-dioxide/nickel(II) complex as the catalyst. This protocol provides a facileroute towards the synthesis of diverse 3,4-disubstituted chroman, tetrahydroquinoline, piperidine and thiochroman derivatives in high yields with good to excellent diastereo- and
In situ mechanochemical synthesis of nitrones followed by 1,3-dipolar cycloaddition: a catalyst-free, “green” route to cis-fused chromano[4,3-c]isoxazoles
作者:Zigmee T. Bhutia、Geethika P.、Anurag Malik、Vikash Kumar、Amrita Chatterjee、Biswajit Gopal Roy、Mainak Banerjee
DOI:10.1039/c5ra21044e
日期:——
An efficient, catalyst free mechanochemical route to cis-fused chromano[4,3-c]isoxazoles has been developed via a simple mortar-pestle grinding method.
A Rapid Intramolecular Imino Diels-Alder Reaction of Aminoanthraquinones with Citronellal or Prenylated Salicylaldehydes: Substituent Effect on Changing the Reaction Pathway from Diels-Alder to Ene-Type Cyclization
作者:Rajagopal Nagarajan、Vikram Gaddam、Ramu Meesala
DOI:10.1055/s-2007-983790
日期:2007.8
The reaction of 1-aminoanthraquinone with citronellal or substituted prenylated salicylaldehyde catalyzed by triphenylphosphonium perchlorate (TPPP) is reported. The nature of the substituents in salicylaldehyde changes the reaction pathway from Diels-Alder to ene-type cyclization.
First Examples of Proline-Catalyzed Domino Knoevenagel/Hetero-Diels-Alder/Elimination Reactions
作者:Gowravaram Sabitha、Narjis Fatima、E. Venkata Reddy、J. S. Yadav
DOI:10.1002/adsc.200505144
日期:2005.8
A novel and efficient one-pot synthesis of lactones (pyranones) has been achieved by domino Knoevenagel/hetero-Diels–Alder/elimination reactions of O- and N-prenyl aldehyde derivatives with Meldrum's acid in the presence of L- or D,L-proline. The reaction proceeds cleanly at room temperature to afford cis- or trans-fused products in good yields with high diastereoselectivity.