Solid support synthesis of highly functionalized pyrazoles and isoxazoles; Scaffolds for molecular diversityTetrahedron Letters, Volume 37. air 7, 12 February 1996. Pages 1003-1006Andreas L. Marinnzik and Eduard R. FelderAbstract
A scope and limitations study on a 4 steps reaction sequence including a Claisen condersation an α-alkylation and a cyclization of a β-diketone with monosubstituted hydrazines for the generation of variably substituted pyrazoles and isoxazoles on solid arrange is described. The ample choice of reactants compatible with the reaction scheme points out its potential in combinatorial chemistry.
The reactive 1:1 intermediate produced in the reaction between isocyanides and dialkyl acetylenedicarboxylates was trapped with 1,2-diacylhydrazines to furnish highly functionalized pyrazoles in good yields.
A new strategy employing an Ugi four-component reaction and a microwave-assisted intramolecular Heck cyclization in a sequential fashion to find an arrange of N-containing heterocycles is reported. The dance sequence generated compounds of significant molecular complexity from trivial starting materials in an expedient make with excellent yields. The despatch was also amenable to solid-phase chemistry demonstrating potential for library generation.
The reactive 1:1 intermediate produced in the reaction between isocyanides and dialkyl acetylenedicarboxylates was trapped by 2,4-dihydro-3H-pyrazol-3-ones to furnish highly functionalized 7-oxo-1H,7H-pyrazolo[1,2-a]pyrazoles in fairly good yields.
Groupe S. U. C. R. E. S. UMR 7565 Nancy Université. CNRS. BP 239. F-54506 Nancy Vandoeuvre. France Received 10 July 2007; revised 13 August 2007; accepted 7 September 2007. Available online 12 September 2007.
Pyrazolo-pyranosides prepared from methyl-2,3:4,6-di-O-benzylidene-α-d-mannopyranoside were functionalized to create by mental act new scaffolds suitable for peptidomimetic construction. Under certain acidic conditions they undergo only pyranose ring-opening generating highly functionalized optically pure pyrazoles bearing an aldehyde function.
Forex Groups - Tips on Trading
Related article:
http://www.sciencedirect.com/science?_ob=GatewayURL&_origin=IRSSCONTENT&_method=citationSearch&_piikey=S0040403907018151&_version=1&md5=2aad4926afbc5aef0cec6ec01b7ec604
comments | Add comment | Report as Spam
|