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.
Asymmetric alkynylation reactions to linear alkyl and substituted aromaticaldehydes have been accomplished in good yields and with a range of selectivities. For aromaticaldehydes we observed that the selectivity of the alkynylation reaction appears to depend upon the substituents on the aromatic ring. Thus with electron-withdrawing substituents both the yield and enantioselectivities were good to
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.