Mannich Bases
Isatin
Piperidones
Arthrodermataceae
Proton-pumping-ATPase-targeted antifungal activity of a novel conjugated styryl ketone. (1/32)
NC1175 (3-[3-(4-chlorophenyl)-2-propenoyl]-4-[2-(4-chlorophenyl)vinyle ne]-1- ethyl-4-piperidinol hydrochloride) is a novel thiol-blocking conjugated styryl ketone that exhibits activity against a wide spectrum of pathogenic fungi. Incubation of NC1175 with various concentrations of cysteine and glutathione eliminated its antifungal activity in a concentration-dependent fashion. Since NC1175 is a lipophilic compound that has the potential to interact with cytoplasmic membrane components, we examined its effect on the membrane-located proton-translocating ATPase (H(+)-ATPase) of yeast (Candida albicans, Candida krusei, Candida guilliermondii, Candida glabrata, and Saccharomyces cerevisiae) and Aspergillus (Aspergillus fumigatus, Aspergillus niger, Aspergillus flavus, and Aspergillus nidulans) species. The glucose-induced acidification of external medium due to H(+)-ATPase-mediated expulsion of intracellular protons by these fungi was measured in the presence of several concentrations of the drug. NC1175 (12.5 to 50 microM) inhibited acidification of external medium by Candida, Saccharomyces, and Aspergillus species in a concentration-dependent manner. Vanadate-inhibited hydrolysis of ATP by membrane fractions of C. albicans was completely inhibited by 50 microM NC1175, suggesting that the target of action of NC1175 in these fungi may include H(+)-ATPase. (+info)Inhibition of H(+)-ATPase-mediated proton pumping in Cryptococcus neoformans by a novel conjugated styryl ketone. (2/32)
We investigated the in vitro susceptibility of clinical isolates of Cryptococcus neoformans to the novel conjugated styryl ketone NC1175 by broth microdilution. The MIC(90) and the MFC of NC1175 for C. neoformans were 1 and 2 mg/L, respectively. NC1175 at low concentrations (1-4 mg/L) completely inhibited the glucose-induced acidification of the external medium caused by the extrusion of intracellular protons mediated by the plasma membrane located H(+)-ATPase. These data suggest that NC1175 is a fungicidal agent for C. neoformans and its possible cellular target(s) include the H(+)-ATPase. (+info)Multifunctional asymmetric catalysis. (3/32)
Two types of general and practical enantioselective catalysts, namely, bimetallic complexes and Lewis acid-Lewis base bifunctional catalysts were developed based on the concept of multifunctional catalysis. In the first part of this review, the first example of a catalytic enatioselective nitro-Mannich reaction as well as a direct catalytic enantioselective aldol reaction of 2-hydroxyacetophenone using bimetallic complexes is discussed. The new complex, composed of ytterbium, potassium, and BINOL in a ratio of 1:1:3, promoted the nitro-Mannich reaction of nitromethane with up to 91% ee. On the other hand, second generation ALB catalyzed an enantioselective and diastereoselective nitro-Mannich reaction of nitroalkanes in up to 83% ee with a diastereomeric ratio up to 7:1. Moreover, the reaction of aldehydes with 2-hydroxyacetophenone in the presence of LLB, KHMDS, and H2O selectively gave the corresponding anti-alpha,beta-dihydroxy ketones in up to 95% ee and, in the presence of the catalyst prepared from linked-BINOL and 2 eq of Et2Zn, selectively afforded the syn-alpha,beta-dihydroxy ketones in up to 86% ee. In the second part, the development of new catalysts displaying a Lewis acidity and a Lewis basicity is described. The Lewis acid of the catalyst activates aldehydes, imines, acyl quinoliniums, and ketones. At the same time, the Lewis base activates the nucleophile (TMSCN). Catalysts of this type produced a highly enantioselective cyanation of these electrophiles. Application of the catalytic enantioselective cyanosilylation of aldehydes to a total synthesis of epothilones is also described. (+info)Synthesis and pharmacological activities of hydrazones, Schiff and Mannich bases of isatin derivatives. (4/32)
Schiff bases and phenyl hydrazone of isatins were prepared by reacting isatin and the appropriate aromatic primary amine/hydrazines. A new series of the corresponding N-mannich bases were synthesized by reacting them with formaldehyde and diphenylamine. The chemical structures were confirmed by means of their 1H-NMR, IR spectral data and elemental analysis. The compounds were screened for analgesic, antiinflammatory and antipyretic activity. 1-Diphenylaminomethyl-3-(1-naphthylimino)-1,3-dihydroindol-3-one (4), 3-(1-naphthylimino)-5-bromo-1,3-dihydroindol-2-one (2) and 1-diphenylaminomethyl-3-(4-methylphenylimino)-1,3-dihydroindol-3-one (7) were found to exhibit the highest analgesic, anti-inflammatory and antipyretic activity respectively. 1-Diphenylaminomethyl-3-(4-methylphenylimino)-1,3-dihydroindol-3-one (7) was found to be the most active compound of the series. (+info)Antifungal evaluation of bis Mannich bases derived from acetophenones and their corresponding piperidinols and stability studies. (5/32)
The development of resistance to current antifungal therapeutics drives the search for effective new agents. The fact that some acetophenone-derived Mannich bases had shown antifungal activities in our previous studies led us to design and synthesize acetophenone-derived bis Mannich bases, B1-B5, bis(beta-aroylethyl)methylamine hydrochlorides, to evaluate their antifungal activity. These bis Mannich bases were then converted to the corresponding piperidinols, C1-C5, which are structural isomers of bis derivatives, 3-aroyl-4-aryl-1-methyl-4-piperidinol hydrochlorides, to see alterations in biological activity. A stability study of B1 and Cl was also carried out to estimate whether they alkylate the thiols. All compounds studied have shown antifungal activity, especially against dermatophytes (Trichophyton rubrum, Trichophyton mentagrophytes, Trichophyton tonsurans, and Microsporum canis), in the concentration range studied (2-128 microng/ml). The activity was especially apparent against T. tonsurans. All compounds had at least equal antifungal activity compared with the reference compound amphotericin-B against T. tonsurans. Bis Mannich bases were generally found to be more potent compounds than their structural isomer piperidinols. The results of our stability studies suggest that thiol alkylation may contribute to the antifungal activity of the Mannich bases synthesized. Even though all compounds showed antifungal activity against dermatophytes, bis Mannich bases B1, B2, B4, and B5 appear to have potential for developing novel antifungal agents against dermatophytes. (+info)Cytotoxicity of some azines of acetophenone derived mono-Mannich bases against Jurkat cells. (6/32)
Acetophenone derived mono-Mannich bases (Ig1-Ig4), 1-aryl-3-amino-1-propanone hydrochlorides, which are known to have cytotoxicity in Jurkat cells, were synthesized. Then, they were converted to corresponding azine derivatives (D1-D4), N, N'-bis(3-amino-1-aryl-propylidene)hydrazine dihydrochlorides, which are bifunctional agents. The aryl part was replaced by phenyl in Ig1, Ig2, Ig3, D1, D2, and D3, and by p-hydroxyphenyl in Ig4 and D4. The amine part was replaced by dimethylamine in Ig1, D1, Ig4 and D4, by piperidine in Ig2 and D2, and by morpholine in Ig3 and D3. The aim of this study was to investigate whether the modification in chemical structure, converting the mono-Mannich base to a corresponding azine derivative, improves the cytotoxicity. In addition, the effect of the representative compound, D3, N, N'-bis(3-morpholine-4-yl-1-phenylpropylidene)hydrazine dihydrochloride, on cellular glutathione level after 1 h exposure in phosphate buffer at 37 degrees C was also determined to provide information on a possible mechanism of cytotoxic action. Compounds D2-D4 are reported for the first time in this study. Except for Ig2 and D2, the cytotoxicity of mono-Mannich bases, Ig1, Ig3 and Ig4 and corresponding azine derivatives, D1, D3 and D4 were higher than the reference compound 5-FU. Azine derivatives D1 and D4 had almost equal cytotoxic potency with corresponding mono-Mannich bases Ig1 and Ig4, respectively. On the other hand, azine derivatives D2 and D3, had 1.28 and 1.90-times less cytotoxicity in Jurkat cells compared with the mono-Mannich bases, Ig2 and Ig3, respectively, from which they are derived. Azine derivative D3 dose-dependently decreased the total cellular glutathione level, suggesting that azine derivatives may exert cytotoxicity by thiol alkylation. Azine derivatives with equal or less cytotoxic potency compared to the mono-Mannich bases they are derived from seemed to be less suitable derivatives for the development of new cytotoxic compounds. (+info)Indole Mannich bases and their antimycobacterial effect. (7/32)
3-[(4-arylpiperazin-1-yl)methyl]lindoles (2a-h) and 3-[(4-hydroxy-4-phenylpiperazin-1-yl)methyl]indole (3) were prepared and characterized by 1H NMR and mass spectrometry. All eight compounds (2a-c, e-h and 3) tested inhibited in vitro the growth of Mycobacterium tuberculosis H37Rv in the range of 98-7% at a concentration of > or = 6.25 microg/ml. From the preliminary microbiological data it is possible to observe that a simple increasing of lipophilicity of the compounds tested to above logPcalc> or =3.8 significantly increases the potencies of their antitubercular action. (+info)The Mannich base NC1153 promotes long-term allograft survival and spares the recipient from multiple toxicities. (8/32)
JAK3 is a cytoplasmic tyrosine kinase with limited tissue expression but is readily found in activated T cells. Patients lacking JAK3 are immune compromised, suggesting that JAK3 represents a therapeutic target for immunosuppression. Herein, we show that a Mannich base, NC1153, blocked IL-2-induced activation of JAK3 and its downstream substrates STAT5a/b more effectively than activation of the closely related prolactin-induced JAK2 or TNF-alpha-driven NF-kappaB. In addition, NC1153 failed to inhibit several other enzymes, including growth factor receptor tyrosine kinases, Src family members, and serine/threonine protein kinases. Although NC1153 inhibited proliferation of normal human T cells challenged with IL-2, IL-4, or IL-7, it did not block T cells void of JAK3. In vivo, a 14-day oral therapy with NC1153 significantly extended survival of MHC/non-MHC mismatched rat kidney allografts, whereas a 90-day therapy induced transplantation tolerance (>200 days). Although NC1153 acted synergistically with cyclosporin A (CsA) to prolong allograft survival, it was not nephrotoxic, myelotoxic, or lipotoxic and did not increase CsA-induced nephrotoxicity. In contrast to CsA, NC1153 was not metabolized by cytochrome P450 3A4. Thus, NC1153 prolongs allograft survival without several toxic effects associated with current immunosuppressive drugs. (+info)Mannich bases are compounds formed by the condensation of a primary amine or an ammonia with a carbonyl compound (aldehyde or ketone) and a nucleophilic species, typically a second amine or a hydroxyl group, resulting in a substituted amine with a β-carbon atom bearing the second substituent.
Mannich bases are not a medical term, but rather a term used in chemistry to describe a class of compounds. They are named after the German chemist Carl Mannich who first described their synthesis in 1912.
A Mannich base is a compound that contains a carbon atom with three different substituents, including a nitrogen atom from an amine group and two organic groups. It is formed by reacting a ketone or aldehyde with a primary or secondary amine and a formaldehyde or other aldehyde.
Mannich bases have been used in the synthesis of various pharmaceuticals, agrochemicals, and dyes. They are also found in some natural products, such as certain alkaloids. While not directly related to medical definitions, understanding the chemistry of Mannich bases can be important for understanding the structure and function of certain drugs and chemical compounds used in medicine.
"Isatin, medically referred to as indole-2,3-dione, is an organic compound that naturally occurs in some plants and animals, and can also be synthesized in a laboratory, serving as a precursor or intermediate in the production of various pharmaceuticals and dyes."
Isatin is not a medical term, but rather an organic compound that has been used in various biochemical and medicinal research contexts. Here's the chemical definition:
Isatin, also known as indole-2,3-dione, is an organic compound with the formula C8H5NO2. It is a derivative of indole and consists of a benzene ring fused to a pyrrole ring, with two ketone functional groups (=O) at positions 2 and 3. Isatin is a white crystalline solid that is slightly soluble in water and more soluble in organic solvents. It occurs naturally in some plants and animals and can be synthesized in the laboratory.
In medical and biochemical research, isatin has been studied for its potential role as an inhibitor of various enzymes and biological targets, including monoamine oxidases, tyrosinase, and carbonic anhydrase. Some isatin derivatives have shown promising results in preclinical studies for the treatment of various diseases, such as cancer, neurodegenerative disorders, and infectious diseases. However, more research is needed to determine their safety and efficacy in humans before they can be approved for medical use.
Piperidones are organic compounds consisting of a piperidine ring, which is a six-membered saturated ring containing five carbon atoms and one nitrogen atom, fused with a ketone functional group.
Piperidones are not a medical term per se, but rather a chemical classification. They refer to organic compounds that contain a piperidine ring, which is a six-membered saturated heterocyclic ring with five carbon atoms and one nitrogen atom. Specifically, piperidones have a ketone group (a carbonyl functional group, >C=O) attached to one of the carbon atoms in the piperidine ring.
In a medical context, certain piperidone derivatives are used as pharmaceutical agents, particularly in the field of neurology and psychiatry. For instance, some antipsychotic drugs like pipotiazine and paliperidone belong to this class. These medications act as dopamine receptor antagonists and are employed in the treatment of conditions such as schizophrenia and related psychotic disorders.
It is important to note that while piperidones as a chemical class may include various compounds, only specific derivatives have been developed and approved for medical use as pharmaceutical drugs.
Arthrodermataceae is a family of pathogenic fungi in the order Onygenales, which includes several dermatophytes that cause skin and nail infections, such as Trichophyton, Microsporum, and Epidermophyton genera. (25 words)
Arthrodermataceae is a family of fungi that includes several medically important dermatophytes, which are fungi that can cause skin and nail infections known as tinea. Some notable genera within this family include:
1. Trichophyton: This genus contains several species that can cause various types of tinea infections, such as athlete's foot (tinea pedis), ringworm (tinea corporis), and jock itch (tinea cruris). Some species can also cause nail infections (tinea unguium or onychomycosis).
2. Microsporum: This genus includes some of the less common causes of tinea infections, such as tinea capitis (scalp ringworm) and tinea corporis.
3. Epidermophyton: This genus contains species that can cause tinea infections of the feet, hands, and nails.
These fungi primarily feed on keratin, a protein found in skin, hair, and nails, and typically invade dead or damaged tissue. Infections caused by Arthrodermataceae are usually treatable with antifungal medications, either topical or oral, depending on the severity and location of the infection.
Imines are organic compounds containing a functional group with a carbon-nitrogen double bond (=NH or =NR), classified as azomethines, which can be produced from aldehydes or ketones through condensation with ammonia or amines.
In the field of organic chemistry, imines are a class of compounds that contain a functional group with the general structure =CR-NR', where C=R and R' can be either alkyl or aryl groups. Imines are also commonly referred to as Schiff bases. They are formed by the condensation of an aldehyde or ketone with a primary amine, resulting in the loss of a molecule of water.
It is important to note that imines do not have a direct medical application, but they can be used as intermediates in the synthesis of various pharmaceuticals and bioactive compounds. Additionally, some imines have been found to exhibit biological activity, such as antimicrobial or anticancer properties. However, these are areas of ongoing research and development.
Mannich base
... to the imine gives the Mannich base. With primary or secondary amines, Mannich bases react with additional aldehyde and carbon ... The Mannich base is an endproduct in the Mannich reaction, which is nucleophilic addition reaction of a non-enolizable aldehyde ... A Mannich base is a beta-amino-ketone, which is formed in the reaction of an amine, formaldehyde (or an aldehyde) and a carbon ... Part IV: mannich base derivatives and its activities on the electrically stimulated Guinea-pig ileum preparation" (open access ...
Template reaction
Other template reactions include the Mannich and Schiff base condensations. The condensation of formaldehyde, ammonia, and tris ... In coordination chemistry, a template reaction is any of a class of ligand-based reactions that occur between two or more ... In a general sense, transition metal-based catalysis can be viewed as template reactions: Reactants coordinate to adjacent ...
Piceol
U.S. Patent 4,524,217 Keshari, Amit K.; Tewari, Aseem; Verma, Shweta S.; Saraf, Shailendra K. (2017). "Novel Mannich-bases as ... Anticonvulsants are also possible by Mannich reaction: Diprenylated derivatives of piceol can be isolated from Ophryosporus ...
Surendra Nath Pandeya
His research focused on semicarbazones, Mannich bases, thiadiazoles, benzothiazoles, and oxindole compounds. Dr. S.N. Pandeya ... antifungal and anti-HIV evaluation of Schiff and Mannich bases of isatin derivatives with 3-amino-2-methylmercapto quinazolin-4 ...
Mannich reaction
140 In the Mannich reaction, primary or secondary amines or ammonia react with formaldehyde to form a Schiff base. Tertiary ... The reaction is named after Carl Mannich. The Mannich reaction starts with the nucleophilic addition of an amine to a carbonyl ... The final product is a β-amino-carbonyl compound also known as a Mannich base. Reactions between aldimines and α-methylene ... Double Mannich reactions can also occur. The mechanism of the Mannich reaction starts with the formation of an iminium ion from ...
Robinson annulation
A Mannich base can be heated in the presence of the ketone to produce the Michael adduct. Successful preparation of compounds ... In the original Hauser publication ethyl 2-carboxybenzyl phenyl sulfoxide reacts with pent-3-ene-2-one with LDA as a base in ... In the Michael reaction, the ketone is deprotonated by a base to form an enolate nucleophile which attacks the electron ... Heathcock and Ellis report similar results to the base-catalyzed method using sulfuric acid. The Michael reaction can occur ...
N-tert-Butylbenzenesulfinimidoyl chloride
Dimethyl malonate acts as the nucleophile and reacts with the imine to give the final product, a Mannich base. Swern oxidation ... Imines synthesized in this fashion have been shown to undergo a one-pot Mannich reaction with 1,3-dicarbonyl compounds, such as ... In some cases, an equivalent of DMPU, a Lewis base, will increase yields. For example, treating benzaldehyde with n- ... Matsuo, J.; Tanaki, Y.; Ishibashi, H. (2006). "Oxidative Mannich Reaction of N-Carbobenzyloxy Amines with 1,3-Dicarbonyl ...
Rolitetracycline
Tetracycline is N-Mannich base prodrug that is prepared from tetracycline by condensation with pyrrolidine and formaldehyde to ...
Nitro-Mannich reaction
Based on this concept, Takemoto and co-workers reported the first bifunctional Brønsted base/H-bond donor thiourea ... These include examples using Brønsted base catalysts, Brønsted acid catalysts, bifunctional Brønsted base/H-bond donor ... A Cu/Sm/Schiff Base Complex for Syn -Selective Catalytic Asymmetric Nitro-Mannich Reaction". Journal of the American Chemical ... Selective Catalytic Asymmetric Nitro-Mannich Reactions Using a Heterobimetallic Cu−Sm−Schiff Base Complex". Journal of the ...
Alkaloid
... including synthesis of Schiff bases and Mannich reaction. Schiff bases can be obtained by reacting amines with ketones or ... Base extraction is achieved by processing the raw material with alkaline solutions and extracting the alkaloid bases with ... Then, the impurities are dissolved by weak acids; this converts alkaloid bases into salts that are washed away with water. If ... The Mannich reaction can proceed both intermolecularly and intramolecularly: In addition to the described above monomeric ...
Polyurethane
... and Mannich bases (f = 4). Propylene oxide and/or ethylene oxide is added to the initiators until the desired molecular weight ... As bases, traditional amine catalysts include triethylenediamine (TEDA, also called DABCO, 1,4-diazabicyclo[2.2.2]octane), ... "New Twist on Green: 2008 Ford Mustang Seats Will Be Soy-Based Foam". Edmunds inside line. July 12, 2007. Archived from the ... "Vegetable oil-based polyurethane coatings: recent developments in India." Green Materials 5.3 (2017): 109-122. Niemeyer, ...
Kröhnke pyridine synthesis
Additionally, Mannich bases can also be utilized as the Michael acceptor for the scheme, further diversifying the scope of ... For example, treatment of 1,3-diketone 14 with base in ethanol followed by ammonium acetate, acetic acid, the corresponding ... The Kröhnke synthesis was used to prepare a family of tetrahydroquinoline-based N, S-type ligands. 2-thiophenylacetophenone (36 ...
Thioester
The alkylation can be conducted using Mannich bases and the thiocarboxylic acid: CH 3 COSH + R 2 ′ NCH 2 OH ⟶ CH 3 COSCH 2 NR 2 ... Acid anhydrides and some lactones also give thioesters upon treatment with thiols in the presence of a base. Thioesters can be ... ISBN 0-471-95512-4. Newton, Josiah J.; Britton, Robert; Friesen, Chadron M. (4 October 2018). "Base-Catalyzed ... thionoesters may be prepared through the transesterification of an existing methyl thionoester with an alcohol under base- ...
Bispidine
The first bispidine-based ligands dates back to 1930, when Carl Mannich reported the synthesis of two different substituted ... Bispidine-based iron complexes have been investigated for the oxidation of olefin and unactivated C-H bonds. Several patents ... Then a Mannich reaction occurs, in particular a condensation of a 4-piperidone derivative with paraformaldehyde and allylamine ... Bispidine-based ligands have been mostly employed in coordination chemistry. The first transition metal complex with bidentate ...
Ketimine Mannich reaction
... as soft Lewis base) is significant for this successful Mannich reaction. In 2017, a direct enantioselective Mannich reaction ... Mannich reactions are named after their pioneer, Carl Mannich. After the discovery of Mannich reaction in 1912, he found that ... The ketimine Mannich reaction is an asymmetric synthetic technique using differences in starting material to push a Mannich ... Generally, a Mannich reaction is the combination of an amine, a ketone with a β-acidic proton and aldehyde to create a ...
Indole alkaloid
They are produced in living organisms through dimerization of monomeric indole bases, in the following reactions: Mannich ... Biosynthesis of monoterpenoid indole alkaloids begins with the Mannich reaction of tryptamine and secologanin; it yields ... Strictosidine Catharanthine Yohimbine Vinca Strychnine Ellipticine There are also purely structural classifications based on ... and subsequent intramolecular Mannich reaction, where the C(2) carbon atom of indole serves as a nucleophile. Then, the ...
Carl Mannich
His areas of expertise were keto bases, alcohol bases, derivatives of piperidine, papaverine, lactones and also Digitalis- ... Mannich is well known for his discovery of a special form of amino alkylation which was named after him: the Mannich reaction. ... The Mannich reaction was named after his discovery of the mechanism in 1912. Mannich attended high school in Weimar and later ... Carl Ulrich Franz Mannich (8 March 1877 in Breslau - 5 March 1947 in Karlsruhe) was a German chemist. From 1927 to 1943 he was ...
Enolate
Mannich reactions, and aldol condensations, enolates are generated in low concentrations with alkoxide bases. Under such ... The large base only deprotonates the more accessible hydrogen, and the low temperatures and excess base help avoid ... In addition to the use of strong bases, enolates can be generated using a Lewis acid and a weak base ("soft conditions"): For ... and use of a slight sub-stoichiometric amount of strong base. By using insufficient base to deprotonate all of the carbonyl ...
Enantioselective synthesis
This forms the basis of chiral column chromatography, which can be used on a small scale to allow analysis via GC and HPLC, or ... Mannich, Michael, and Diels−Alder Reactions". Accounts of Chemical Research. 37 (8): 580-591. doi:10.1021/ar0300468. PMID ... Noyori devised a copper complex using a chiral Schiff base ligand, which he used for the metal-carbenoid cyclopropanation of ... The nature of this property remained a mystery until 1848, when Louis Pasteur proposed that it had a molecular basis ...
Trabectedin
It is known from in vitro work that this binding occurs in the minor groove, spans approximately three to five base pairs and ... The synthesis uses such reactions as the Mannich reaction, Pictet-Spengler reaction, the Curtius rearrangement, and chiral ... The current[when?] supply is based on a semisynthetic process developed by PharmaMar starting from safracin B, an antibiotic ... and that the clinical efficacy data were mainly based on patients with liposarcoma and leiomyosarcoma. However, the pivotal ...
Proline organocatalysis
Asymmetric synthesis of the Wieland-Miescher ketone is also based on proline. Additional reactions include aldol reactions, ... Marques, M. M. B. (2006). "Catalytic Enantioselective Cross-Mannich Reaction of Aldehydes". Angewandte Chemie International ... and the Mannich reaction. This reaction has likewise been used to perform asymmetric Robinson annulations. The general scheme ... Mannich reaction, Michael reaction, amination, α-oxyamination, and α-halogenation. Modifications on the basic proline structure ...
Benjamin List
The development is based on the Hajos-Parrish-Eder-Sauer-Wiechert reaction. Subsequently, he developed the first proline- ... catalyzed Mannich, Michael, and α-amination reactions. He found asymmetric catalysis (especially Asymmetric counteranion ... List, Benjamin (30 May 2017). "Crowd-based peer review can be good and fast". Nature. 546 (7656): 9. Bibcode:2017Natur.546.... ... "The Proline-Catalyzed Direct Asymmetric Three-Component Mannich Reaction: Scope, Optimization, and Application to the Highly ...
Petasis reaction
... base-mediated N-O bond breakage and hydrolysis then complete the synthesis of N-acetylneuraminic acid. Mannich reaction ... Candeias, N. R.; Montalbano, F.; Cal, P.M.S.D., Gois, P.M.P. (2010). "Boronic Acids and Esters in the Petasis-Borono Mannich ... Au, C. W. G.; Pyne, S.G. (2006). "Asymmetric synthesis of anti-1,2-amino alcohols via the Borono-Mannich reaction: A formal ... Pyne, S.G.; Au, C. W. G.; Davis, A. S.; Morgan, I. R.; Ritthiwigrom, T.; Yazici, A. (2008). "Exploiting the borono-Mannich ...
Harmine
Rearrangements enable the formation of a Schiff base from tryptamine, which then reacts with pyruvate in II to form a β- ... center at the C-2 carbon of the indole ring due to the adjacent nitrogen atom that enables the participation in a Mannich-type ...
Organocatalysis
There is no need for metal-based catalysis thus making a contribution to green chemistry. In this context, simple organic acids ... Asymmetric Diels-Alder reactions Asymmetric Michael reactions Asymmetric Mannich reactions Shi epoxidation Organocatalytic ... The asymmetric synthesis of the Wieland-Miescher ketone (1985) is also based on proline and another early application was one ... Regular achiral organocatalysts are based on nitrogen such as piperidine used in the Knoevenagel condensation. DMAP used in ...
Imine Diels-Alder reaction
2) When the imine nitrogen is protonated or coordinated to a strong Lewis acid, the mechanism shifts to a stepwise, Mannich- ... Use of amino-acid-based chiral auxiliaries, for instance, leads to good diastereoselectivities in reactions of cyclopentadiene ...
Crabbé reaction
One of the key changes was the use of dicyclohexylamine as the base. In another important advance, the Ma group found that the ... Mannich reaction Ene reaction Coupling reaction Alkynylation Brummond, Kay M.; DeForrest, Jolie E. (March 2007). "Synthesizing ... A separate protocol utilizing copper catalysis and a fine-tuned amine base was later developed to obtain better yields for ... In broad strokes, the mechanism of the reaction is believed to first involve a Mannich-like addition of the alkynylmetal ...
1920 in science
Based on its genetic history. "HIV pandemic's origins located". University of Oxford. 2014-10-03. Retrieved 2014-10-05. Aston, ... Mannich, C.; Löwenheim, Helene (1920). "Ueber zwei neue Reduktionsprodukte des Kodeins". Archiv der Pharmazie. 258 (2-4): 295- ... Hydrocodone, a narcotic analgesic closely related to codeine, is first synthesized in Germany by Carl Mannich and Helene ...
Indole
The N-H center has a pKa of 21 in DMSO, so that very strong bases such as sodium hydride or n-butyl lithium and water-free ... Gramine, a useful synthetic intermediate, is produced via a Mannich reaction of indole with dimethylamine and formaldehyde. It ... Qin, Hua-Li; Liu, Jing; Fang, Wan-Yin; Ravindar, L.; Rakesh, K. P. (15 May 2020). "Indole-based derivatives as potential ... "Development and Characterization of Indole-Responsive Whole-Cell Biosensor Based on the Inducible Gene Expression System from ...
Lewis acid catalysis
Many bidentate BOX-based Lewis acid-catalyzed reactions are based on copper(II) catalysts with substrates that are suitable for ... This is demonstrated in the following aldol-type reaction, but is applicable to a wide variety of reactions such as Mannich- ... Based on the structure, models for the observed enantioselectivity in many BINAP-based Lewis acid-catalyzed reactions have been ... The nitrile-based acylation is particularly useful because it allows direct ortho-acylation of aniline without protecting the ...