Stereoselective Reactions. XXXIV.1) Enantioselective Deprotonation of Prochiral 4-Substituted Cyclohexanones Using Chiral Bidentate Lithium Amides Having a Bulky Group Instead of a Phenyl Group on the Chiral Carbon

Autor:	Keizo Sugasawa, Norio Tokutake, Masaharu Toriyama, Shigeyasu Motohashi, Kenji Koga
Rok vydání:	2001
Předmět:	chemistry.chemical_classification Trimethylsilyl chloride Ketone Enantioselective synthesis Substituent General Chemistry General Medicine Medicinal chemistry chemistry.chemical_compound Deprotonation chemistry Asymmetric carbon Drug Discovery Enol ether Organic chemistry Phenyl group
Zdroj:	CHEMICAL & PHARMACEUTICAL BULLETIN. 49:468-472
ISSN:	1347-5223 0009-2363
Popis:	Using chiral bidentate lithium amides having a bulky group instead of a phenyl group on the chiral carbon, enantioselective deprotonation of prochiral 4-substituted cyclohexanones in the presence of excess trimethylsilyl chloride was examined in THF in the absence and in the presence of HMPA. It is shown that enantioselectivity of the reactions decreases as the substituent on the chiral carbon of the chiral lithium amides and the substituent at the 4-position of cyclohexanones become reasonably bulky. An eight-membered cyclic transition state model is proposed for this deprotonation reaction.
Databáze:	OpenAIRE
Externí odkaz:	https://explore.openaire.eu/search/publication?articleId=doi_________::50ecc437d78a71b1ab18055ae67e8257 https://doi.org/10.1248/cpb.49.468 Zobrazit plný text záznamu