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.
The synthesis and biological evaluation of a range of novel functionalised benzopyrans as potential potassium channel activators
作者:Elizabeth Tyrrell、Kibur Hunie Tesfa、Iain Greenwood、Alistair Mann
DOI:10.1016/j.bmcl.2007.11.135
日期:2008.2
A range of novel benzopyrans have been synthesised and biologically evaluated for K-ATP channel activity employing cromakalim 1 as a benchmark K-ATP channel opener. Although the compounds that were evaluated demonstrated a reduced ability to relax phenylephrine stimulated rat thoracic tissue, we provide evidence that benzopyrans 7a-h may be operating via an alternative mechanism than ATP-sensitive K+ channel activity. (C) 2008 Published by Elsevier Ltd.