Montmorillonite K-10 catalyzed Mannich reaction: Synthesis of aminonaphthoquinone derivatives from Lawsone

An efficient one-pot protocol for the synthesis of 2-((substituted amino)(4-phenyl)methyl)-3-hydroxy-naphthalene-1,4-dione derivatives has been developed by the three-component reaction of 2-hydroxy-naphthalene-1,4-dione, aromatic aldehydes and anilines/heterocyclic amines using montmorillonite K-10 as a catalyst. The advantages of this method include short reaction time, excellent yield and easy work-up.     

Preparation of partially functionalised resorcinarene derivatives

The conditions for synthesis of mono-, di- and trifunctionalised resorcinarenes by catalysed Mannich reaction are described. A series of these compounds are functionalised with different functional groups.     

斯德酮与芳香胺的Mannich反应

3－（4－甲基苯甲酰基乙基）斯德酮和3－（3－羟基－3－苯基丙基）斯德酮 可以与芳香胺发生Mannich反应，得到斯德酮与芳香胺的Mannich碱。     

N-Benzylazacyclophane synthesis via aromatic Mannich reaction

A new method for synthesizing phenolic N-benzylazacyclophanes starting from tyramine is presented here. Computational calculations showed that macrocyclization is favored by the formation of hydrogen bond-based templates; these templates are not affected by including benzyl groups in the nitrogen atom of the tyramine moiety. The results showed that N-benzyl groups with electron-donating substituents have more nucleophilic nitrogen atoms, thereby favoring macrocyclization, while electron-withdrawing groups favor polymerization.     

百里香酚的Mannich反应及其产物的抑菌活性

作为单萜类家族的成员之一,百里香酚(thymol)主要来源于百里香属植物中,是百里香挥发油的主要组成成分,具有广泛的杀菌、抗氧化、消炎、祛痰、去蛔和除螨等活性[1].     

Parallel synthesis of an indole-based library via an iterative Mannich reaction sequence

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.     

Synthesis and NO production inhibition of novel Mannich base derivatives of irisolidone

Five new C-8 Mannich base derivatives of irisolidone 2a-2e were synthesized and their nitric oxide（NO）production inhibitory activity was evaluated.Compounds 2a,2b,2c and 2e displayed stronger activities in vitro than the parent compound irisolidone.     

Pentafluorophenyltrifluorosilane in the silicon Mannich reaction

The synthesis of α-C₆F₅-substituted amines by a three-component coupling reaction of C₆F₅SiF₃, aromatic aldehydes, and N-trimethylsilylamines has been elaborated. The optimized conditions include performing the reaction in dimethylformamide in the presence of stoichiometric amounts of lithium acetate.     

Synthesis and characterization of chiral, bridged resorcinarenes as templates for asymmetric catalysis

A full study of the synthesis of chiral, bridged resorcinarenes (3a-3l, 13a, 13b) is presented using Mannich condensation of C_2v-tetraprotected resorcinarenes with chiral 1,n-diamines bearing homochiral α-methylbenzyl auxiliaries at each terminal nitrogen. The study has revealed the methodology to be applicable to preparing a broad range of bridged structures with varying lengths of bridge, different functionality in the bridge and various protecting groups on the upper rim. Reproducible and satisfactory yields in the reaction were only obtained with the pendant R group as methyl. The bridged adducts have been fully characterized by a range of spectroscopic techniques, and NMR has revealed varying trends in the way the various bridges protrude into the cavity. Low temperature NMR as well as X-ray structures of tetramesylate 15 and tetratoluate 3g has revealed hydrogen bonding to the amine nitrogens in the bridge to be an important control element for positioning the bridge relative to the cavity of the bowl. The derivatives provide chiral templates for asymmetric catalysis studies using cooperative effects in the bowl.     

A catalyst-and solvent-free multicomponent synthesis of 7-azagramine analogues via a Mannich type reaction

A catalyst-and solvent-free protocol for the synthesis of 7-azagramine analogues is described via a three-component Mannich type reaction between 7-azaindole, aromatic aldehydes and heterocyclic amines in acceptable to excellent yields. Structures of the compounds were confirmed satisfactorily by ¹H NMR, IR, mass, TOCSY, HSQC and HMBC spectral analyses.     

New compounds via Mannich reaction of cytosine, paraformaldehyde and cyclic secondary amines

The Mannich reaction of cytosine, paraformaldehyde and cyclic secondary amines in the presence of acetic acid gives 5-(4′-morpholinyl)methylcytosine, 5-(1′-piperidinyl)methylcytosine, 5-(1′-pyrrolidinyl)methylcytosine, 5-(4′-methyl-1′-piperidinyl)methylcytosine, 5-(3′-methyl-1′-piperidinyl)methylcytosine and 5-(2′-methyl-1′-piperidinyl)methylcytosine. These products are quite different from those obtained via cytosine aminomethylation previously described in the literature.     

Synthesis of Resorcinarene Derivatives by the Catalyzed Mannich Reaction,Part 2: Resorcinarene Derivatives with Unsaturated Bonds

The conditions of a simple synthesis of alkenyloxymethyl and the alkynyloxymethyl derivatives of resorcinarene by the Mannich reaction catalyzed with iminodiacetic acid are described. The synthesis presented in this article is effective and uses readily available and inexpensive substrates.     

Theoretical study of aminoalkylation in the Mannich reaction of furan with methyleneimminium salt

The potential energy surface for the reaction of furan and methyleneimminium cation with formation of a Mannich base has been studied using AM1 and PM3 semiempirical calculations. Nonspecific solvent effects were taken account of in the framework of the multicavity self-consistent reaction field approach. Characteristics of the reaction path elucidated for various media are discussed. © 1998 John Wiley & Sons, Inc. Int J Quant Chem 67: 359–366, 1998     

Synthesis of Resorcinarene Derivatives via the Catalyzed Mannich Reaction,Part 3: Glycol Derivatives of Resorcinarene

A series of resorcinarene glycol derivatives have been synthesized as secondary substitution products via a Mannich reaction catalyzed by iminodiacetic acid. The products are potentially useful candidates as podands for supramolecular chemistry. The synthesis presented in this article is effective and uses readily available and inexpensive substrates.     

Novel one-pot Cu-nanoparticles-catalyzed Mannich reaction

Recyclable heterogeneous Cu-nanoparticles efficiently catalyzed the one-pot three-component Mannich reaction of ketones, aromatic aldehydes and amines in methanol. This method provides a novel and improved method for obtaining β-amino carbonyl compounds in terms of good yield with little catalyst loading.     

Covert Mannich Reaction via Carbon Transfer

1,3‐Dimethylbenzimidazolidine reacts with ketones, which can provide activating α hydrogens and primary or secondary amines under acidic conditions, to yield aminomethylation derivatives by a covert Mannich reaction.     

Anti-selective direct asymmetric Mannich reaction catalyzed by protease

The anti-selective direct asymmetric Mannich reaction of (hetero) aromatic aldehydes, 4-anisidine and O-protected hydroxyacetones for the synthesis of stereodefined anti-β-amino-α-hydroxycarbonyl compounds was developed. Protease type XIV from Streptomyces griseus (SGP) was used as a biocatalyst in 1,4-dioxane/phosphate buffer under mild reaction conditions. The excellent diastereoselectivities of up to >99:1 (anti/syn) and good enantioselectivities of up to 90% ee were achieved. This method provides a more sustainable complement to chemically catalyzed anti-selective direct asymmetric Mannich reactions.     

Highly efficient one-pot, three-component Mannich reaction catalysed by boric acid and glycerol in water with major ‘syn’ diastereoselectivity

Boric acid and glycerol efficiently catalysed the one-pot, three-component Mannich reaction of aldehydes, aromatic amines and cyclic ketones in water at ambient temperature to afford the corresponding β-amino carbonyl compounds in good yields. All but one reaction proceeded with moderate ‘syn’ diastereoselectivity. This observation is just the reverse of the major anti diastereoselectivity obtained in most of the earlier reported procedures. The methodology is mild and efficient using minute quantities of catalyst with no side products and a very simple work-up procedure.     

A simple and eco-friendly method for the aminomethylation of 3-substituted oxindoles via three-component Mannich reaction in aqueous media

A simple and eco-friendly method for the aminomethylation of various 3-substituted oxindoles via three-component Mannich reaction in aqueous media has been established. A variety of oxindoles containing a quaternary carbon center, which comprises an aminomethyl group were obtained smoothly in good yields (up to 93%) with this method. Particularly valuable features, such as employing cheap and readily available formalin as a useful aminomethylation C1 unit and using water as a reaction medium, are embodied in this method.