共查询到20条相似文献,搜索用时 46 毫秒
1.
Elsayed M. Afsah Ez-el-Din M. Kandil Soha M. Abdelmageed Fatma T. Elbarhmtoushi 《Journal of heterocyclic chemistry》2020,57(1):346-354
Treatment of isoindolin-1,3-dione ( 1 ) with formalin and the appropriate amine or diamine afforded new N-Mannich bases and bis-(Mannich bases) 2 to 6 . The use of the appropriate hydrazide or dihydrazide as the amine component in the Mannich reaction with 1 led to Mannich bases and bis-(Mannich bases) incorporating a hydrazide moiety. The synthetic potential of sec-Mannich bases as precursors in synthesis of hybrid Mannich bases incorporating 1 was described. The N-alkylation of 1 with ketonic Mannich bases was investigated. 相似文献
2.
HUANG Wenqiang CHENG Shaoling CHEN Yu SUN Weimin HE Binglin Institute of Polymer Chemistry Nankai University Tianjin China 《Chinese Journal of Reactive Polymers》2000,(2)
1.INTRODUCTIONCombinatorialsynthesisisapowerfultoolforpreparationanddiscoveryofdrugleads[1].However,becauseofthelackofefficientanalyticalmeanstocharacterizetheintermediatesandsmallamountofbyproductsonthepolymersupportsproducedinsolid-phasesynthesis,manychemistshaveturnedtheirintereststosolution-phasemethodsforlibrarygenerationinsteadofsolid-phasesynthesis[2].Buttheconventionalseparationtechniquescannotmeettherequirementtopurifyeveryproductofasolution-phaselibrary,thusthesolid-phasescavenge… 相似文献
3.
TheoreticalStudiesontheMechanismofMannichReactionInvolvingIminiumSaltasPotentialMannichReagent(1)——UseAcetaldehydeasPseudo┐ac... 相似文献
4.
Since the early studies of Mannich, Mannich reaction has become an important tool for the synthesis of new compounds. Mannich bases can be either directly employed or used as intermediates. In this work, the one‐carbon unit transfer reaction of tetrahydrofolate coenzyme was initiated. 1,3‐Dimethylimidazolidine as a new tetrahydrofolate coenzyme model at formaldehyde oxidation level was used to react with ketone having active hydrogen atoms and amine to give the corresponding Mannich base in good yield by a covert Mannich reaction. A novel method for biomimetic synthesis of various Mannich bases is provided. 相似文献
5.
Structures, heats of formation, and vibrational eigenvalues have been calculated by semiempirical AM 1 quantum mechanical method for the reactants, products, and activated complexes of three Mannich reactions, namely, the reaction between potential Mannich reagent H2N+ = CH2Cl? and furan and the conventional Mannich reactions between ammonia, formaldehyde, and furan in neutral and acidic media. It has been found that the Mannich reaction involving the potential Mannich reagent occurs more quickly than do the conventional Mannich reactions in neutral medium; the Mannich reaction in acidic medium proceeds most quickly. The results have been discussed in terms of the orbital match and static electric interaction between some atoms of reactant complexes. © 1995 John Wiley & Sons, Inc. 相似文献
6.
《Journal of heterocyclic chemistry》2018,55(3):736-742
The reaction of isatin 1 with benzaldehyde and a sec‐amine or the appropriate aldimine afforded the N‐Mannich bases 2 – 3 and the bis‐base 4 . Treatment of 1 with glutaric dialdehyde and morpholine gave the bis‐base 5 . Mannich reaction of the Schiff bases 6a – f derived from 1 , led to the new Mannich bases and bis‐bases 7 – 9 . The use of N‐methyl‐D‐glucamine as the amine component in the Mannich reaction with 6b – f led to the polyhydroxy Mannich bases 11 – 13 . 相似文献
7.
Marigo M Kjaersgaard A Juhl K Gathergood N Jørgensen KA 《Chemistry (Weinheim an der Bergstrasse, Germany)》2003,9(10):2359-2367
The first catalytic asymmetric direct Mannich reaction of malonates and beta-keto esters has been developed. Malonates react with an activated N-tosyl-alpha-imino ester catalyzed by chiral tert-butyl-bisoxazoline/Cu(OTf)(2) to give the Mannich adducts in high yields and with up to 96% ee. These reactions create a chiral quaternary carbon center and it is demonstrated that this new direct Mannich reactions provides for example a new synthetic procedure for the formation of optically active beta-carboxylic ester alpha-amino acid derivatives. A series of different beta-keto esters with various ester substituents has been screened as substrates for the catalytic asymmetric direct Mannich reaction and it was found that the best results in terms of yield, diastereo- and enantioselectivity were obtained when tert-butyl esters of beta-keto esters were used as the substrate. The reaction of different beta-keto tert-butyl esters with the N-tosyl-alpha-imino ester gave the Mannich adducts in high yields, diastereo- and enantioselectivities (up to 95% ee) in the presence of chiral tert-butyl-bisoxazoline/Cu(OTf)(2) as the catalyst. To expand the synthetic utility of this direct Mannich reaction a diastereoselective decarboxylation reaction was developed for the Mannich adducts leading to a new synthetic approach to attractive optically active beta-keto alpha-amino acid derivatives. Based on the stereochemical outcome of the reactions, various approaches of the N-tosyl-alpha-imino ester to the chiral bisoxazoline/Cu(II)-substrate intermediate are discussed. 相似文献
8.
把3-[N,N-双(羧甲基)氨甲基]邻苯二酚和哌啶,吡咯,二乙胺,吗啉和哌嗪在加热可得到相应的5-取位Mannich碱.研究了Mannich反应的机理,理解了这一Mannich反应的定位是由于反应物的分子内氢键.但是在与亚胺基二乙酸反应时或3-吗啉甲基邻苯二酚与吗啉反应,得到正常的6-取代Mannich碱. 相似文献
9.
芳香胺参加的Mannich反应——3-芳氨基-3-苯基-1-(4-溴苯基)丙酮的合成 总被引:2,自引:0,他引:2
文献报道过芳香胺与苯甲醛生成的Schiff碱可在少量相应的芳香胺盐酸盐或浓盐酸催化下制备Mannich碱(Ⅰ),所用的Schiff碱系事先合成,且产率较低(15-68.9%)。本文报导用4-溴苯乙酮、苯甲醛和芳香胺在少量浓盐酸催化下能直接发生Mannich反应, 相似文献
10.
Ibrahem I Zou W Engqvist M Xu Y Córdova A 《Chemistry (Weinheim an der Bergstrasse, Germany)》2005,11(23):7024-7029
The direct three-component asymmetric Mannich reaction catalyzed by acyclic chiral amines or amino acids is presented. Simple acyclic chiral amines and amino acids--such as alanine-tetrazole (9), alanine, valine, and serine-catalyzed the three-component asymmetric Mannich reactions between unmodified ketones, p-anisidine, and aldehydes with high chemo- and stereoselectivity, furnishing the corresponding Mannich bases with up to >99 % ee. This study demonstrates that the whole range of amino acids in nature, as well as nonproteogenic amino acid derivatives, can be considered in the design and tuning of novel, inexpensive organocatalysts for the direct asymmetric Mannich reaction. 相似文献
11.
The transition metal salt-catalyzed direct three-component Mannich reactions of aryl aldehydes, aryl ketones, and carbamates are described. The RuCl(3).xH(2)O-, AuCl(3)-PPh(3)-, and AuCl(3)-catalyzed direct Mannich reactions led to the synthesis of N-protected beta-aryl-beta-amino ketones, and the results create new possibilities for exploiting the transition metal salt-catalyzed direct Mannich reaction and facile synthesis of beta-amino ketone libraries. 相似文献
12.
Diazo esters, arylboranes, and carbamoyl imines undergo a 3-component Mannich condensation reaction. Catalyzed by Cu(II) salts, the reaction affords the corresponding isocyanate Mannich product: one that can be easily trapped in situ by other nucleophiles. The Mannich condensation corresponds to an α,α-disubstituted enolate addition to imines. The reaction was rendered asymmetric by using the (-)-phenylmenthol ester in good yield and selectivities. 相似文献
13.
Swor CD Hanson KR Zakharov LN Tyler DR 《Dalton transactions (Cambridge, England : 2003)》2011,40(34):8604-8610
Non-coordinated hydroxymethylphosphines react readily with primary and secondary amines by the phosphorus Mannich reaction. To determine if this reactivity can be used to synthesize phosphine macrocycles, trans-Fe(DHMPE)(2)Cl(2) (DHMPE = 1,2-bis(dihydroxymethylphosphino)ethane) was prepared and reacted with various amines. However, no phosphorus Mannich reactivity was observed. In order to understand why no reactions occurred, the Mannich reactivity of the borane-coordinated hydroxymethylphosphines DHMPE·2BH(3) and Ph(2)PCH(2)OH·BH(3) was investigated. These borane-coordinated phosphines also did not undergo the phosphorus Mannich reaction. These results suggest that the lone pair of electrons on the phosphorus atom is essential for the phosphorus Mannich reaction to occur, and therefore it is not possible to use this reaction in a templated synthesis of phosphine macrocycles. It is speculated that the mechanism of the phosphorus Mannich reaction may involve a methylenephosphonium intermediate, analogous to an iminium in the standard Mannich reaction. X-ray crystal structures of trans-Fe(DHMPE)(2)Cl(2) and DHMPE·2BH(3) are also presented. Both crystal structures display an extended hydrogen-bonding network in the solid state. 相似文献
14.
A library of 1,3-disubstituted indoles has been prepared via an iterative Mannich reaction sequence. The first Mannich reaction with secondary amines and formaldehyde preferentially yields 3-aminomethyl indoles, while the second Mannich reaction introduces an additional aminomethyl group at the N1-position of the indole ring. A library of 25 substituted indoles has thus been prepared in moderate to good yields with purity. 相似文献
15.
16.
Aime S Cavallotti C Gianolio E Giovenzana GB Palmisano G Sisti M 《Organic letters》2004,6(8):1201-1204
The Mannich reaction was successfully employed to obtain two pyridine-based ligands 1 and 2. The latter represents the first example of a Mannich reaction leading to a 12-membered pyridine-containing macrocycle. [reaction: see text] 相似文献
17.
This paper describes a combinatorial synthesis the mannich bases in Solution through the Mannich reaction using 3 ketones,5 amines and formaldehyde in solution and hydrochloride as a catalyst and then using a macroporous quarterized ammonium resin(CO32-form)as a scavenge agent to remove the acid catalyst when the Mannich reaction is completed.It was found by GC/MS analysis that the symmetrical ketone,such as acetone,in the Mannich reaction mainly produces one Mannich base;while the asymmetrical ketone,such as 2-pentanone,gives two. 相似文献
18.
A catalytic Mannich reaction of a simple ester with no activating functionality at the α-position via a product-base mechanism was reported. The desired Mannich adducts were obtained in high yields using a catalytic amount of KH. This is a rare example of a Br?nsted base-catalyzed Mannich reaction of unactivated esters as substrates. 相似文献
19.
Amino acids have been found to participate as the amine component in the Mannich reaction with both ketones and phenols. The phenolic Mannich bases may be cyclized with sulfuric acid to 1,2-dihydro-4(3/H)isoquinolones. In the presence of thionyl chloride the same Mannich bases undergo lactonization to benz[f]-1,4-oxazepin-4(3H)ones. 相似文献
20.
Li Yuan MOU Zi Yun LIN Li Ya ZHU* Xiao Tian LIANG Institute of Materia Medica Chinese Academy of Medical Sciencesand Peking Union Medical College Beijing Center for Biophysical Science Engineering University of Alabama at Birmingham 《中国化学快报》2001,(6)
Mannich reaction is widely used for the synthesis of many kinds of compounds1. In the synthesis of the derivatives of styryl ketonic Mannich bases, a one-pot method is used, in which ketone, secondary-amine hydrochloride, paraformaldehyde are refluxed together in alcohol2,3. In most cases the normal Mannich product MA is obtained. But when certain amine is used as the reactant, a side-product IM, instead of MA is obtained. MS and 1HNMR data indicate that compound IM is a new type of Man… 相似文献