Acylation of aromatic substrates with ketenes. II. Hammett–Brown studies on substituted aromatic compounds

Autor:	K. R. Fountain, Greg Gerhardt, Paul John, Pamela Heinze, Dave Maddox
Rok vydání:	1980
Předmět:	Organic Chemistry Ketene General Chemistry Chloride Medicinal chemistry Catalysis Acylation chemistry.chemical_compound chemistry Reagent Benzene derivatives medicine Organic chemistry Vinyl cation Diphenylketene medicine.drug
Zdroj:	Canadian Journal of Chemistry. 58:1939-1946
ISSN:	1480-3291 0008-4042
Popis:	Competition reactions using dimethylketene (DMK) – aluminum chloride complexes on a variety of substituted benzene derivatives gave partial rate factors. The logs of these Pfx values when plotted versus σ+ values gave two line segments of ρ = −6.59 for less active substrates, and ρ = −0.92 for more active substrates. Similar results were found for diphenylketene (ρ = −9.47 and −1.07).These results were rationalized by analogy to vinyl cation alkylations. A pair of π complexes (outer then inner) occur between initial approach of the reagent and final, product-determining π-complex formation. In one of these complexes the C=C bond of the ketene complex may be able to back-bond in a manner similar to that found in inorganic complexes of CO and metals.
Databáze:	OpenAIRE
Externí odkaz:	https://explore.openaire.eu/search/publication?articleId=doi_dedup___::f5b6b552f3f1b3e0e7a9b3b3b4e5ecb2 https://doi.org/10.1139/v80-308 Zobrazit plný text záznamu