Алкилирование енаминов, бета-дикетонов и енаминокетонов
from cyclohexane-1,3-dione may be controlled by the
nature of the base used.Our results indicate that monoalkylation is
completely regioselective; lithium diisopropylamide leads to ?’-alkylated
compounds while lithium bis(trimethylsilyl)amide affords ?-alkylated
products.In contrast, alkylation of ?’- or ?-substituted compounds always
occurs in the ?’-position regardless of the base.
Regiospecificity and Regioselectivity of the Alkylation, Acylation,
Sulfenylation and Sulfonylation of Pyrrolidine Enaminones
Thomas Burgemeister; Gerd Dannhardt; Ernst Eibler; Brigitte Paulus; Klaus
Ziereis
Source details: Arch.Pharm.(Weinheim Ger.) 1988, 321 : 345-
348.
Document type: Journal
CODEN: ARPMAS
Language: GE
CNR: 5807249
Abstract
Different methods to modify a pyrrolidine enaminone regiospecifically or
regioselectively at the N- and C-atom, respectively, are described.All
compounds have been isolated and characterized, in case of the alkylation
reactions the ratio of regioisomers is determined by HPLC.NOE experiments
are performed in order to prove the configuration of some adducts.
Reactivity of N-substituted enaminones with unsaturated carbonyl compounds
Esther Caballero; Blanca Madrigal; Manuel Medarde; Pilar Puebla; Zoila
Honores; et al.
Source details: Ach.Mod.Chem. 1998, 135 : 4 457-474.
Document type: Journal
CODEN: ACMCEI
Language: EN
CNR: 6101721
Abstract
The reactivity of enaminones of 2-aminoethanol and 2-aminoethanothiol
towards polyelectrophilic reagents has been studied.A brief overview of our
previous results with this enaminones, which allowed us to describe new
synthesis of fused heterocycles, is included. In the present work, only the
formation of C-C bond is a common feature of the reaction, to produce
derivatives or simple heterocycles.Although no fused heterocycles were
obtained, the reaction products have complex functionalization which will
allow further cyclization to such a class of polyfused systems.
Reactions between Enaminones and Enones. Part 2. C versus N-Alkylation with
Cyclohex-2-enone. Structure Confirmation by Reduction of a Dienaminone
Derivative of Dehydrated Dimedone Dimer
Ibrahim Chaaban; John V. Greenhill; Mohamed Ramli
Source details: J.Chem.Soc.Perkin Trans.1 1981, 3120-3124.
Document type: Journal
CODEN: JCPRB4
Language: EN
CNR: 5625982
Abstract
Primary and secondary enaminones derived from cyclohexane-1,3-dione,
dimedone, and acetylacetone react with cyclohexenone to give exclusively C-
alkylated derivatives.In every case the products form carbinolamines which
exist as 1-hydroxy-2-azacyclo[3.3.1]nonenes.This was confirmed in some
examples by formation of an extra ring between nitrogen and oxygen.A series
of dienaminones were prepared from 2-(5,5-dimethyl-3-oxocyclohex-1-enyl)-
5,5-dimethylcyclohexane-1,3-dione and one of these was reduced to give an
azanonene identical with that from C-alkylation.
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