Synthesis of Heterocycles via Cycloadditions I

ISBN-13: 9783540783688 / Angielski / Twarda / 2008 / 229 str.

Alfred Hassner

Opis

Heterocyclicmoleculesplayasigni?cantroleinlifeprocessesandhaveplayed a major rolein industrial developments of the last century, for instance in the ?eld of dyes, pharmaceuticals, pesticides, polymers etc. They comprise not onlysomeofthemostinterestingandbiologicallyimportantnaturalproducts like alkaloids, carbohydrates, nucleic acids, and antibiotics but include many practical drugs and a large segment of known synthetic organic compounds. Hencescientistshavedevotedagreatamountofeffortto?ndoptimalsynthetic approachesto a variety ofheterocyclic compounds. Amongthemostsuccessfulandselectivesyntheticprocessesarecycload- tionreactions, since theyinvolvesimultaneous orsequential formationoftwo ormorebondsoftenwithahighdegreeofstereoselectivityandregioselectivity. Forinstance, 1,3 dipolar cycloadditionsareelectronicallyequivalent to Diels Alder reactions and are among the most common 5-membered ring-forming systems. In addition they usually proceed with a high degree of stereo- and regio-control.It is therefore, not surprising that synthesis of many important classesofheterocycles, includingthoseofusefulbiologicallyactivemolecules, haveutilized cycloadditionsteps intheir formation.Furthermore, manyhe- rocyclesserve as intermediates in the synthesis of polyfunctional molecules. In this volume we present ?ve selected contributions by well-known - thors, each an authority in his ?eld. The ?rst chapter deals with construction ofisoxazolines(dihydroisoxazoles)via1,3-dipolarcycloadditionsofnitronates or of nitrile oxides generated from nitroalkanes. This includes inter- as well as intramolecular processes. Many of these heterocycles possess important synthetic and biological properties and are shown to lead to stereo- and - gioselectiveintroductionofmultifunctionalmoleculessuchasaminoalcohols, ?-amino acids, aldols, nitriles, and others."

Spis treści

I.N.N. Namboothiri, N. Rastogi: Isoxazolines from Nitro Compounds: Synthesis and Applications.- S. Bräse, A. Friedrich, M. Gartner, T. Schröder: Cycloaddition Reactions of Azides Including Bioconjugation.- C. Nájera, J.M. Sansano: Enantioselective Cycloadditions of Azomethine Ylides.- S. Muthusamy, J. Krishnamurthi: Heterocycles by Cycloadditions of Carbonyl Ylides Generated from Diazo Ketones.- R. Schobert, C. Hölzel: Heterocycles from Unsaturated Phosphorus Ylides.