NHC-mediated enantioselective formal [4 + 2] cycloadditions of alkylarylketenes and β,γ-unsaturated α-ketocarboxylic esters and amides

Autor:	Stuart M. Leckie, David Pryde, Alexandra M. Z. Slawin, Andrew D. Smith, Tomas Lebl, T. Bruce Brown
Rok vydání:	2013
Předmět:	Models Molecular Molecular Structure Chemistry Stereochemistry Organic Chemistry Enantioselective synthesis Carboxylic Acids Esters Stereoisomerism Ethylenes Ketones Crystallography X-Ray Biochemistry Amides Cycloaddition Cyclization Heterocyclic Compounds Physical and Theoretical Chemistry Methane
Zdroj:	Organicbiomolecular chemistry. 11(19)
ISSN:	1477-0539
Popis:	Chiral N-heterocyclic carbenes (NHCs) promote the asymmetric formal [4 + 2] cycloaddition of alkylarylketenes with β,γ-unsaturated α-ketocarboxylic esters and amides. Divergent diastereoselectivity is observed in this process, with γ-aryl-β,γ-unsaturated α-ketocarboxylic esters and amides giving preferentially syn-dihydropyranones (up to 68 : 32 dr syn : anti, up to 98% ee), while γ-alkyl-derivatives generate anti-dihydropyranones (up to 18 : 82 dr syn : anti, up to 75% ee).
Databáze:	OpenAIRE
Externí odkaz:	https://explore.openaire.eu/search/publication?articleId=doi_dedup___::bc31ff88b6f5d32f3931cfbcb579467b https://pubmed.ncbi.nlm.nih.gov/23584232 Zobrazit plný text záznamu