Substituted γ and δ-ketoaldehydes may be conveniently synthesized in two steps from imine carbanions, which are obtained by reaction with hyperbasic media. These anions are stable at low temperature (−30°); they react with functional electrophiles to afford masked ketoaldehydes which may be cyclised into various cyclopentenones or cyclohexenones.
1,5-Dicarbonyl-Verbindungen durch Michael-Addition deprotonierter Enamine und Allylamine an 2-(<i>N</i>-Methylanilino)-acrylnitril
作者:Hubertus Ahlbrecht、Manfred Dietz、Lothar Weber
DOI:10.1055/s-1987-27904
日期:——
1,5-Dicarbonyl Compounds via Michael-Addition of Deprotonated Enamines and Allylamines to 2-(N-Methylanilino) acrylonitrile A new method for the synthesis of the title compounds by a onepot, three component, coupling reaction is described. Is consists of the reaction of a homoenolate anion and an enol cation equivalent with subsequent alkylation of an acyl-anion equivalent. Hence the methodology of Umpolung is used in a threefold manner within the reaction sequence.
The invention provides a compound of formula I:
wherein A
1
, A
2
, A
3
, R
1
, X, Y, and B have any of the values described herein, as well as salts of such compounds, compositions comprising such compounds, and therapeutic methods that comprise the administration of such compounds. The compounds are inhibitors of monoamine oxidase B (MAO-B) enzyme function and are useful for improving cognitive function and for treating psychiatric disorders in animals.
molecules by incorporating a key enzymatic step into the synthesis. Herein, we describe a general biocatalytic approach for the enantioselective preparation of 2,6-disubstituted piperidines starting from easily accessible pro-chiral ketoenones. The strategy represents a new biocatalytic disconnection, which relies on an ω-TA-mediated aza-Michael reaction. Significantly, we show that the reversible enzymatic
Benzoxazine and benzothiazine derivatives and pharmaceutical compositions containing them
申请人:Bhuniya Debnath
公开号:US20050113368A1
公开(公告)日:2005-05-26
The present invention relates to novel antidiabetic, hypolipidemic, antiobesity and hypocholesterolemic compounds of formula (I) their derivatives, their analogs, their tautomeric forms, their stereoisomers, their polymorphs, their pharmaceutically acceptable salts, their pharmaceutically acceptable solvates and pharmaceutically acceptable compositions containing them, to a process for preparing such compounds. More particularly, the present invention relates to novel alkyl carboxylic acids of the general, their derivatives, their analogs, their tautomeric forms, their stereoisomers, their polymorphs, their pharmaceutically acceptable salts, their pharmaceutically acceptable solvates and pharmaceutically acceptable compositions containing them, to a process for preparing such compounds. The present invention also relates to processes for the preparation of the compounds of formula (I), novel intermediates, processes for their preparation, their use in the preparation of the above said compounds and their use as antidiabetic, hypolipidemic, antiobesity and hypocholesterolemic compounds.