Phase-transfer catalysed asymmetric epoxidation of enones using N-anthracenylmethyl-substituted Cinchona alkaloids

Autor:	P. G. Wainwright, Barry Lygo
Rok vydání:	1999
Předmět:	chemistry.chemical_classification biology Chemistry Aryl Organic Chemistry Enantioselective synthesis Cinchona Cinchona Alkaloids biology.organism_classification Biochemistry Catalysis Reaction rate chemistry.chemical_compound Drug Discovery Organic chemistry Ammonium Alkyl
Zdroj:	Tetrahedron. 55:6289-6300
ISSN:	0040-4020
DOI:	10.1016/s0040-4020(99)00205-7
Popis:	A study into the enantioselective epoxidation of α,β-unsaturated ketones utilising Cinchona alkaloid-derived quaternary ammonium phase-transfer catalysts bearing an N-anthracenylmethyl function is presented. It has been found that the O-benzyl derivatives of these catalysts in conjunction with sodium hypochlorite give high enantio- and diastereoselectivities in the epoxidation of a range of substrates R1CH=CHCOR2, where R1=alkyl or aryl and R2=aryl. In the cases where R2=alkyl high enantioselectivity has also been observed, however the rate of reaction is substantially reduced. Application of this process to the enantioselective synthesis of a range of trans-α, β-epoxy ketones (e.e. 71–90%) is presented.
Databáze:	OpenAIRE
Externí odkaz:	https://explore.openaire.eu/search/publication?articleId=doi_________::525249ba8b002ef8ee4b8dccb7b8a983 https://doi.org/10.1016/s0040-4020(99)00205-7 Zobrazit plný text záznamu Full Text from ScienceDirect