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   Реферат: Алкилирование енаминов, бета-дикетонов и енаминокетонов

-      обнаружена значительная зависимость хода реакции бензилирования (3-амино-6,6-диметилбицикло[3.1.0]гекс-2-ен-2-ил)метилкетона от температуры реакционной смеси. Установлено, что оптимальный выход С-бензилированного производного достигается при t≥35˚C.

-      установлен тот факт, что “комнатная” температура – весьма ненадежная характеристика методики синтеза.

                                             


Литература.

1.      S. Dyke // Chemistry of enamines. // Cambridge University Press, Cambridge, 1973.

2.      A. Cook (ed) // Enamines: synthesis, structure and reactions. // Marcell Decker, New York, 1969.

3.      I. Chaaban, J. Greenhill, M. Ramli // Reactions between enaminones and enones. Part 2. C versus N-alkylation with cyclohex-2-enone. Structure confirmation by reduction of a dienaminone derivative of a dehydrated dimedone dimer. // J. Chem. Soc. Perkin Trans., 1981, 1, 3120-3124.

4.      J. Whitesell, M. Whitesell // Alkylation of ketones and aldehydes via their nitrogen derivatives. // Synthesis, 1983, 7, 517-536.

5.      A. Zanina, S. Shergina, I. Sokolov, M. Shvartsberg // Alkylation of sterically hindered 1,3-diketones under phase-transfer conditions. // Russ. Chem. Bl., 1996, 45, 2389-2392 // Izv. Akad. Nauk Ser. Khim. 1996, 10, 2518-2521.

6.      S. Lu, A. Lewin // Enamine-imine tautomerism in α,β-unsaturated α-amino acids. // Tetrahedron, 1998, 54, 15097-15014.

7.      J. Henriksen, S. Hammerum // Heats of formation of imine and enamine radical cations and the corresponding neutral molecules // Int. J. Mass Spect, 1998 179/180, 301-308.

8.      S. Caccamese, G Principato // Resolution of the enantiomers of tetrahydrozoline by chiral HPLC. The racemization of the enantiomers via an imine-enamine tautomerism. // Tetrahedron: Asymmetry, 1998, 9, 2939-2945.

9.      M. Shimizu, A. Morita, T. Kaga // Double nucleophilic addition to α,β-unsaturated aldimines induced by titanium tetrahalides. // Tetrahedron Lett., 1999, 40, 8401-8405.

10.    S. Knüppel, R. Frölich, G. Erker // Formation of functionalized [3]ferrocenophane derivatives by an enamine condensation reaction.// J. Organomet. Chem., 2000, 595, 308-312.

11.    A. Tkachev, A. Rukavishnikov // Enaminones of the 2-acetylcyclopent-1-en-1-ylamine type derived from the terpenic compounds limonene, 3-carene and δ-cadinol. // Mendeleev Commun., 1992, 1, 161-162.

12.    S. Popov, A. Tkachev // New chiral agents for resolution of racemic cis-permethric and cis-Z-cyhalothric acids. // Tetrahedron: Asymmetry, 1995, 6, 4, 1013-1018.

13.    J. Greenhill, A. Moten // N-Alkylation of enaminones. // Tetrahedron, 1983, 39, 3405-3408.

14.    A. Tkachev, S. Popov // Alkylation of enaminoketone with a modified carane skeleton. Formation of stable β-diketone monoimines. // Russ. J. Org. Chem., 1997, 33, 5, 601-606.

15.    T. Tiner-Harding, P. Mariano // Intramolecular photoarylations of N-(haloaryl)ethyl-β-enaminones. // J. Org. Chem., 1982, 47, 482-485.

16.    P. Bugler, I. Cottrell, C. Cowden, A. Davies, U. Dolling // An investigation into the alkylation of 1,2,4-triazole // Tetrahedron Lett., 2000, 41, 1297-1301.


Приложение 1

Данные и аннотации некоторых статей (Belstein Abstracts).

Alkylation of Enaminoketone with a Modified Carane Skeleton. Formation of Stable b-Diketone Monoimines

A. V. Tkachev; S. A. Popov

 Source details:               Russ.J.Org.Chem. 1997, 33 : 5 601-606.

 Document type:              Journal

 CODEN:                         RJOCEQ

 Language:                      EN

 CNR:                            6090629

 Original Source:            Zh.Org.Khim. 1997, 33 : 5 660-665.

 CODEN:                        ZORKAE

 Language:                      RU

 Abstract

 Alkylation of a bicyclic enaminoketone, 1-((1R,5R)-3-amino-6,6-dimethylbicyclo[3.1.0]hex-2-en-2-yl))ethanone, with highly reactive alkyl halides (methyl iodide, benzyl halides, and allyl halides) in a two-phase system benzene-40% aqueous NaOH in the presence of benzyltriethylammonium chloride (BTEA) as phase-transfer catalyst results in formation of stable b-diketone monoimines, derivatives of the series of 1-((1R,5R)-2-alkyl-3-imino-6,6-dimethylbicyclo[3.1.0]hex-2-yl)ethanone, in 53-81% yields.

Alkylation of sterically hindered 1,3-diketones under phase-transfer conditions

A. S. Zanina; S. I. Shergina; I. E. Sokolov; M. S. Shvartsberg

 Source details:                Russ.Chem.Bl. 1996, 45 : 10 2389-2392.

 Document type:              Journal

 CODEN:                       RCBUEY

 Language:                     EN

 CNR:                             6056087

 Original Source:             Izv.Akad.Nauk Ser.Khim. 1996, 10 2518-2521.

 CODEN:                       IASKEA

 Language:                     RU

 Abstract

 Sterically hindered 1,3-diketones react selectively with propargyl and allyl bromides under conditions of phase transfer catalysis to give C-alkylated products, whereas reactions with butyl and benzyl chlorides yield mixtures of C- and O-isomers.An increase in the size of the substituents present in the initial 1,3-diketone hampers introduction of the second propargyl group.The propargyl-substituted 1,3-diketones undergo cyclization under the alkylation conditions to give substituted furans.


Sequence of alkylation of cyclohexane-1,3-dione. Alternative synthesis of (+/-)-angustione

A. A. Zenyuk; L. G. Lis; L. I. Ukhova

 Source details:               Chem.Nat.Compd.(Engl.Transl.) 1991, 27 : 4 400-403.

 Document type:              Journal

 CODEN:                        CHNCA8

 Language:                      EN

 CNR:                             5645800

 Original Source:            Khim.Prir.Soedin. 1991, 4 460-463.

 CODEN:                        KPSUAR

 Language:                     RU

 Abstract

 A method is proposed for introducing one, two, or three alkyl substituents into positions 4 and 6 of the cyclohexane-1,3-dione molecule by successive alkylation under the action of strong bases. (+/-)-Angustione (a natural -diketone) has been synthesized.

A Tandem Amino-Cope Rearrangement/Enamine Alkylation Reaction

Steven M. Allin; Martin A. C. Button; Stephen J. Shuttleworth

 Source details:              Syn.Lett. 1997, 6 725-727.

 Document type:             Journal

 CODEN:                        SYNLES

 Language:                     EN

 CNR:                              6086563

 Abstract

 Thermally induced (3,3)-sigmatropic rearrangement of 3-amino-1,5-diene substrates occurs to give the corresponding enamine products in high yield and with excellent trans:cis enamine selectivity.The enamine produced during the amino-Cope rearrangement has been directly derivatized, representing the first report of a tandem amino-Cope rearrangement/enamine alkylation reaction.The potential of this novel synthetic strategy is outlined.

N-alkylation of enaminones

John V. Greenhill; Ashraf M. Moten

 Source details:              Tetrahedron 1983, 39 : 20 3405-3408.

 Document type:             Journal

 CODEN:                        TETRAB

 Language:                     EN

 CNR:                             5609239

 Abstract

 The base catalyzed N-alkylation of a series of primary and secondary enaminones has been examined in detail.The enaminone anion was found to be a weak nucleophile.Best results were obtained in tetrahydrofuran or dioxane with sodium hydride and an alkyl iodide.


Alkylation of Ketones and Aldehydes via their Nitrogen Derivatives

James K. Whitesell; Marilyn A. Whitesell

 Source details:              Synthesis 1983, 7 517-536.

 Document type:             Journal

 CODEN:                     SYNTBF

 Language:                   EN

 CNR:                           5572282

 Abstract

 In this review, methods for the alkylation of the aldehydes and ketones via formation of nitrogen derivatives such as enamines, metallated imines (imine anions), metallated N,N-dialkylhydrazones (N,N-dialkylhydrazone anions), dimetallated oximes (oxime dianions), and metallated O-methyloximes (O-methyloxime anions) are described.Scope, limitations, and advantages or disadvantages of the methods over comparative reactions of enolates are also mentioned.

Intramolecular Photoarylations of N-(Haloaryl)ethyl β-Enaminones

Tammy Tiner-Harding; Patrick S. Mariano

 Source details:               J.Org.Chem. 1982, 47 : 3 482-485.

 Document type:             Journal

 CODEN:                         JOCEAH

 Language:                      EN

 CNR:                              5570323

 Abstract

 The photochemistry of several N-(haloaryl)ethyl β-enaminones was investigated in order to develop methods for preparation of tricyclic enaminone systems.The efficiencies of intramolecular photoarylations of the haloaryl systems were found to be dependent upon the wavelength of irradiation.Accordingly, irradiations of the haloaryl β-enaminones 9a,c,d,f with Pyrex-filtered light leads to formation of the reduced N-cyclized and C-cyclized products 9b or 9e, 8a or 8b, and 10a or 10b, respectively. The major products in these processes are the reduced materials.In contrast, irradiations of the bromoaryl enaminones 9c or 9f with Vycor-filtered light results in high yielding conversions to the C-cyclized tricyclic enaminones 10a and 10b in synthetically useful yields ranging from 50% to 85%.A discussion of reasons for these wavelength dependencies is given in terms of excited-state discrimination in these bichromophoric systems.Possible reaction mechanisms are considered.The origin of another major product, 11, generated by irradiation of 9f with Vycor-filtered light, is also discussed.

Regioselective control of N-aryl enaminone alkylation

Denise Dugat; Daniel Gardette; Jean-Claude Gramain; Bertrand Perrin

 Source details:              Bull.Soc.Chim.Fr. 1994, 131 : 1 66-70.

 Document type:             Journal

 CODEN:                        BSCFAS

 Language:                    EN

 CNR:                            5851695

 Abstract

 The regioselectivity of the C-alkylation of unsubstituted N-aryl enaminones prepared 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 α’-alkylated compounds while lithium bis(trimethylsilyl)amide affords γ-alkylated products.In contrast, alkylation of α’- or γ-substituted compounds always occurs in the α’-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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