Amination Of Aldehydes Research Articles

Direct and Indirect Reductive Amination of Aldehydes and Ketones with Solid Acid Activated Sodium Borohydride under Solvent‐Free Conditions.

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Reductive Amination of Aldehydes and Ketones with Sodium Borohydride Supported Onto HZSM-5 Zeolite Under Microwave Irradiation in a Solvent Free System

Sodium borohydride supported onto a HZSM-5 zeolite is presented as a general reducing agent for the reductive amination of aldehydes and ketones under microwave irradiation in solventless system.

TiCl(OiPr)3 and NaBH(OAc)3: An Efficient Reagent Combination for the Reductive Amination of Aldehydes by Electron‐Deficient Amines.

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Efficient Synthesis of N-Alkyl Tetrahydroisoquinolines by Reductive Amination

An expedient access to diverse N-alkyl 1,2,3,4-tetrahydroisoquinolines is reported by reductive amination of aldehydes and ketones with tetrahydroisoquinoline (THIQ) in the presence of Ti(Oi-Pr) 4 and NaBH 4 . The N-alkyl THIQ products were rapidly purified by flow-through catch and release technique using commercially available polymer-supported sulfonic acid, MP-TsOH columns.

HCl‐Catalyzed Stereoselective Mannich Reaction in H2O—SDS System.

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Direct and indirect reductive amination of aldehydes and ketones with solid acid-activated sodium borohydride under solvent-free conditions

A simple and convenient procedure for reductive amination of aldehydes and ketones using sodium borohydride activated by boric acid, p-toluenesulfonic acid monohydrate or benzoic acid as reducing agent under solvent-free conditions is described.

Synthesis and antimycobacterial activities of glycosylated amino alcohols and amines

Reduction of glycosyl β-amino esters ( 6– 14 and 25– 30) with lithium aluminum hydride resulted in glycosyl amino alcohols ( 15– 23 and 31– 36) in good yields. However, reductive amination of glycosyl aldehydes ( 1– 3) with different amines in presence of sodium borohydride resulted in good to moderate yields of glycosyl amines ( 37– 41). All the compounds were evaluated for antitubercular activity against Mycobacterium tuberculosis H 37Ra and H 37Rv. Compounds 18, 21, 35 and 36 exhibited antitubercular activities with MIC ranging from 6.25 to 3.12 μg ml –1.

Basic function of Cu/Ni-based catalyst in a colloidal state for one-pot amination alcohols to N,N-dimethyl tertiary amines

One-pot amination of fatty alcohols with dimethylamine at normal pressure, using Cu/Ni-based colloidal catalyst stabilized by barium sterate (Cu/Ni/Ba colloidal catalyst, Cu:Ni:B = 5:1:1). proceeded without charging bulk hydrogen with an amine yield of more than 90%. It demonstrated the effective use of active hydrogen, generated by the dehydrogenation of a starting alcohol over copper, for the following hydrogenolysis of an aldehyde-dimethylamine adduct to form the final product, N,N-dimethil-long alkyl-tertiary amines. The basic function generated by the combination of copper and nickel, especially in a colloidal state, was named as “Self-supplying System for Active Hydrogen”. On the other hand, reductive amination of aldehydes with dimethylamine, in the presence of hydrogen flow at a normal pressure using the same colloidal catalyst, proceeded with an amine yield of 40–80%, and significant amount (12–26%) of aldols were formed. These observations demonstrated the essential difference between one-pot amination of alcohols containing active hydrogen and reductive amination of aldehydes in the presence of bulk hydrogen which has to be activated separately. This is the first description of basic function of Cu/Ni-based catalyst by the original inventors of the catalytic system. More than five-fold increase in catalytic activity by incorporation of calcium stearate with Cu/Ni was observed for one-pot amination of fatty alcohols. Comparison of catalytic activity of Cu/Ni-based catalyst in a colloidal state and in a solid state showed superiority of the former catalyst in catalytic activity, 40–50 times higher based on a unit amount of copper.

Studies on the reactions between daptomycin and glyceraldehyde

The objectives of this project were to determine the reaction pathways of daptomycin in the presence of glyceraldehyde in acidic solutions, and to quantitate the kinetics of the major pathways. In the presence of glyceraldehyde (pH range 1–7 at 25 to 60 °C), daptomycin formed two major products separable by RP-HPLC. The products were identified using UV spectroscopy, fluorimetry, mass spectrometry, and 2D- 1H NMR. The reaction scheme involved the reversible formation of imine and anilide derivatives. Carbinolamine was believed to be a common intermediate in formation pathways of both products. The carbinolamine intermediate underwent either acid catalyzed dehydration resulting in imine formation or intramolecular hydrogen bonding and bond cleavage giving rise to anilide formation. In mild acid conditions, both products reversed to daptomycin. The reaction between daptomycin and glyceraldehyde was first-order with respect to both reactants. In a pH range of 1–7, the imine formation rate was pH dependent with a maximum rate at approximate pH values of 3–4. The observed pH dependence was consistent with the pH dependence of typical amine–aldehyde reactions.

HCl-Catalyzed Stereoselective Mannich Reaction in H2O-SDS System

HCl-catalyzed Mannich reaction of cyclic ketone, aromatic aldehyde, and aromatic amine proceeded smoothly in water in the presence of SDS to afford the corresponding β-amino ketone with high anti selectivity.

High Loading Polymer Reagents Based on Polycationic Ultraresins. Polymer‐Supported Reductions and Oxidations with Increased Efficiency.

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One‐Pot Reductive Amination of Aldehydes and Ketones with α‐Picoline‐borane in Methanol, in Water, and in Neat Conditions.

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Synthesis and radioiodination of some daunorubicin and doxorubicin derivatives

Daunorubicin and doxorubicin are efficient agents for cancer treatment. Their clinical efficacy is, however, hampered by their indiscriminant toxicity. This problem may be circumvented by encapsulating the drugs in liposomes and selectively targeting the tumor cells using tumor targeting agents. Furthermore, the antitumor effect could be enhanced by attaching the Auger electron emitter, 125I, to daunorubicin and doxorubicin derivatives. In this context a number of ester, amide, and amine derivatives of daunorubicin and doxorubicin were synthesized. Benzoic acid ester derivatives of daunorubicin were synthesized by nucleophilic esterification of the 14-bromodaunorubicin with the potassium salt of the corresponding benzoic acid, resulting in good yields. Nicotinic acids and benzoic acids, activated with a succinimidyl group, were coupled to the amino group of daunorubicin to give the corresponding amide derivatives. Amine derivatives were obtained by the reductive amination of aromatic aldehydes with daunorubicin hydrochloride. The stannylated ester and amide derivatives were used as precursors for radioiodination. Radiolabeling with 125I was performed using chloramine-T as an oxidant. The optimized labeling resulted in high radiolabeling yields (85–95%) of the radioiodinated daunorubicin and doxorubicin derivatives. Radioiodination of the amines was conducted at the ortho position of the activated phenyl rings providing moderate radiochemical yields (55–75%).

A Selective Reductive Amination of Aldehydes by the Use of Hantzsch Dihydropyridines as Reductant.

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High loading polymer reagents based on polycationic Ultraresins. Polymer-supported reductions and oxidations with increased efficiency

Ultraresin 1 was prepared from highly branched polyethylene imine ( M n=10,000) via reductive cross-linking with terephthaldialdehyde. Following quaternization with methyl iodide, the polycationic Ultraresin 2 , with iodide as a counterion, was obtained. These novel resins combine low swelling with high mechanical stability. By anion exchange polycationic Ultraresins carrying borohydride ( 3 ) and periodate ( 22 ) were generated and were investigated as very high loading polymer reagents. Ultra-borohydride resin 3 had a reducing activity of up to 12 mmol/g depending on the substrate. It proved successful in diverse reductions including those of aldehydes, ketones, and nitroolefines. The resin was employed in the reductive amination of aldehydes with an excess of amines, which were removed by the use of a scavenger resin. Periodate resin 22 was obtained with an active loading of up to 5.4 mmol/g and was employed in oxidations of sulfides, diols, hydroquinones, and hydrazines.

One-pot reductive amination of aldehydes and ketones with α-picoline-borane in methanol, in water, and in neat conditions

A one-pot reductive amination of aldehydes and ketones with amines using α-picoline-borane as a reducing agent is described. The reaction has been carried out in MeOH, in H 2O, and in neat conditions in the presence of small amounts of AcOH. This is a highly efficient and mild procedure that is applicable for a wide variety of substrates. In particular, this is the first successful demonstration that this type of reaction can be carried out in water and in neat conditions.

A selective reductive amination of aldehydes by the use of Hantzsch dihydropyridines as reductant

Direct reductive amination of an aldehyde was carried out using a Hantzsch dihydropyridine as the reductant in the presence of a catalytic amount of scandium triflate. The reaction was highly selective towards aldehydes over ketones, and other reducible functional groups did not affect the reaction.

Direct Catalytic Asymmetric Amination of Aldehydes: Synthesis of Evans Oxazolidinones and α‐Amino Acids

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Reductive Amination of Glycosyl Aldoses: Synthesis of N‐Glycosylated β‐Glycosyl Amino Alcohols and their Enzyme Inhibitory Effect#

Reductive amination of glycosyl aldehydes (1a–c, 2) with glycosyl amino esters (3a–c, 4) in the presence of sodium borohydride gave diglycosylated amino esters (5–15) in good yield. N‐Glycosyl‐glycosylated amino esters were reduced to the respective diglycosyl amino alcohols (16–26) with LiAlH4 in good yield. All the synthesized compounds were studied for their inhibitory effect, if any, against hepatic glucose‐6‐phosphatase, glycogen phosphorylase, and intestinal brush border membrane α‐glucosidase; among these compounds 7, 21, and 25 have shown marked inhibition on these enzymes, respectively. #CDRI Communication No. 6605.

A Facile Synthesis of 4‐Aryl‐1H‐pyrazolo[3,4‐b]quinolines

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