An Unexpected Michael-Aldol-Smiles Rearrangement Sequence for the Synthesis of Versatile Optically Active Bicyclic Structures by Using Asymmetric Organocatalysis

Autor:	Caterina Tiberi, Hao Jiang, Nicole Holub, Karl Anker Jørgensen, Márcio W. Paixão
Rok vydání:	2010
Předmět:	Bicyclic molecule Stereochemistry Organic Chemistry Enantioselective synthesis General Chemistry Metathesis Catalysis chemistry.chemical_compound chemistry Aldol reaction Intramolecular force Organocatalysis Trifluoroacetic acid Smiles rearrangement
Zdroj:	Chemistry - A European Journal. 16:4337-4346
ISSN:	1521-3765 0947-6539
Popis:	A facile and simple organocatalytic procedure to generate optically active 6-alkyl- and 6-aryl-substituted bicyclo[2.2.2]oct-5-en-2-ones is presented. The reaction is catalysed by a 9-amino-9-deoxyepiquinine trifluoroacetic acid salt, which activates alpha,beta-unsaturated cyclic ketones for the 1,4-addition of beta-keto benzothiazoyl sulfones in a stereoselective fashion. Subsequent intramolecular aldol reaction and Smiles rearrangement gives rise to important optically active bicycles, which are a common motif in natural products, ligands in asymmetric catalysis and substrates for Cope rearrangements, photochemical reactions, radical cyclisations and metathesis. Different bicyclic structures were obtained by utilisation of various cyclic enones or by performing ring-expanding reactions. Furthermore, two possible mechanistic pathways are outlined and discussed.
Databáze:	OpenAIRE
Externí odkaz:	https://explore.openaire.eu/search/publication?articleId=doi_dedup___::7fd58b0281f16b8196018c091b218b25 https://doi.org/10.1002/chem.200903274 Zobrazit plný text záznamu Plný text