scholarly journals A consecutive process for C–C and C–N bond formation with high enantio-and diastereo-control: direct reductive amination of chiral ketones using hydrogenation catalysts

2019 ◽  
Vol 55 (45) ◽  
pp. 6409-6412 ◽  
Author(s):  
Sophie H. Gilbert ◽  
Virginie Viseur ◽  
Matthew L. Clarke
Keyword(s):  
Reductive Amination ◽  
Bond Formation ◽  
High Yield ◽  
Hydrogenation Catalysts ◽  
Chiral Ketones ◽  
Rh Catalyst

A Rh catalyst derived from tri-(2-furyl)phosphine enables the direct reductive amination of 1,3-substituted ketones to occur in high yield and diastereoselectivity.

scholarly journals C-N Bond Formation by Consecutive Continuous-Flow Reductions towards A Medicinally Relevant Piperazine Derivative

Molecules ◽  
2021 ◽  
Vol 26 (7) ◽  
pp. 2040
Author(s):  
Zsolt Fülöp ◽  
Péter Bana ◽  
István Greiner ◽  
János Éles
Keyword(s):  
Antipsychotic Drug ◽  
Catalytic Hydrogenation ◽  
Continuous Flow ◽  
Reductive Amination ◽  
Reduction Method ◽  
Bond Formation ◽  
Aluminum Salt ◽  
Line Extraction ◽  
Piperazine Derivative ◽  
Step Procedure

A new, continuous-flow consecutive reduction method was developed for the C-N bond formation in the synthesis of the key intermediate of the antipsychotic drug cariprazine. The two-step procedure consists of a DIBAL-H mediated selective ester reduction conducted in a novel, miniature alternating diameter reactor, followed by reductive amination using catalytic hydrogenation on 5% Pt/C. The connection of the optimized modules was accomplished using an at-line extraction to prevent precipitation of the aluminum salt byproducts.

scholarly journals Cathodic hydrodimerization of nitroolefins

2015 ◽  
Vol 11 ◽  
pp. 1163-1174 ◽  
Author(s):  
Michael Weßling ◽  
Hans J Schäfer
Keyword(s):  
Double Bond ◽  
Nitro Group ◽  
Bond Formation ◽  
Cathodic Reduction ◽  
High Yield ◽  
Easy Access ◽  
Electrolysis Cell ◽  
Aldehydes And Ketones ◽  
Nef Reaction

Nitroalkenes are easily accessible in high variety by condensation of aldehydes with aliphatic nitroalkanes. They belong to the group of activated alkenes that can be hydrodimerized by cathodic reduction. There are many olefins with different electron withdrawing groups used for cathodic hydrodimerization, but not much is known about the behaviour of the nitro group. Synthetic applications of this group could profit from the easy access to nitroolefins in large variety, the C–C bond formation with the introduction of two nitro groups in a 1,4-distance and the conversions of the nitro group by reduction to oximes and amines, the conversion into aldehydes and ketones via the Nef reaction and base catalyzed condensations at the acidic CH bond. Eight 1-aryl-2-nitro-1-propenes have been electrolyzed in an undivided electrolysis cell to afford 2,5-dinitro-3,4-diaryl hexanes in high yield. The 4-methoxy-, 4-trifluoromethyl-, 2-chloro- and 2,6-difluorophenyl group and furthermore the 2-furyl and 2-pyrrolyl group have been applied. The reaction is chemoselective as only the double bond but not the nitro group undergoes reaction, is regioselective as a ß,ß-coupling with regard to the nitro group and forms preferentially two out of six possible diastereomers as major products.

Visible Light-Promoted C–C Bond Formation from Hydroxyaryls in Water

2019 ◽  
Vol 72 (12) ◽  
pp. 978 ◽  
Author(s):  
Dafne Saporito ◽  
Sergio A. Rodriguez ◽  
Maria T. Baumgartner
Keyword(s):  
Visible Light ◽  
Bond Formation ◽  
High Yield ◽  
Reaction Yield ◽  
Halogen Lamp ◽  
One Pot ◽  
Direct Arylation ◽  
Photoinduced Reactions ◽  
Optical Applications ◽  
Very High

An eco-friendly and direct arylation of hydroxyaryls in water using photoinduced reactions with different substrates (1-bromo-2-naphthol, 1-iodo-2-naphthol, N-(2-iodophenyl)acetamide, 5-bromouracil, 2-iodo-N-methylbenzamide, and 2-iodobenzamide) was studied. For example, π-expanded coumarins, compounds with potential optical applications, were synthesized in very high yield, without the use of toxic reagents, in a one-pot reaction. In addition, we demonstrate that the irradiation source (halogen lamp) can be efficiently replaced by an LED without altering the reaction yield.

One-pot synthesis of carbazoles via tandem C–C cross-coupling and reductive amination

2016 ◽  
Vol 14 (1) ◽  
pp. 122-130 ◽  
Author(s):  
Deuk-Young Goo ◽  
Sang Kook Woo
Keyword(s):  
Natural Products ◽  
Reductive Amination ◽  
Bond Formation ◽  
Cross Coupling ◽  
Synthetic Route ◽  
One Pot ◽  
Highly Efficient ◽  
One Pot Synthesis ◽  
Synthetic Utility

We have developed a highly efficient synthetic route to carbazoles that employs sequential C–C/C–N bond formation via Suzuki cross-coupling and Cadogan cyclization. The developed method is compatible with electron neutral, rich or deficient substrates. The synthetic utility of this method was demonstrated by the concise syntheses of four natural products.

scholarly journals Flow synthesis of secondary amines over Ag/Al2O3 catalyst by one-pot reductive amination of aldehydes with nitroarenes

RSC Advances ◽  
2017 ◽  
Vol 7 (72) ◽  
pp. 45856-45861 ◽  
Author(s):  
Ekaterina A. Artiukha ◽  
Alexey L. Nuzhdin ◽  
Galina A. Bukhtiyarova ◽  
Valerii I. Bukhtiyarov
Keyword(s):  
Reductive Amination ◽  
Flow Reactor ◽  
Secondary Amines ◽  
High Yield ◽  
One Pot ◽  
Flow Synthesis ◽  
Al2o3 Catalyst

The reaction of aldehydes with nitroarenes over Ag/Al2O3 catalyst under H2 in a flow reactor gives secondary amines in high yield.

scholarly journals Easy assembly of ligands for glycosidase affinity chromatography

1990 ◽  
Vol 270 (2) ◽  
pp. 539-540 ◽  
Author(s):  
R C Bernotas ◽  
B Ganem
Keyword(s):  
Amino Acids ◽  
Affinity Chromatography ◽  
Enzyme Purification ◽  
Reductive Amination ◽  
Water Soluble ◽  
High Yield ◽  
Glycosidase Inhibitors ◽  
Neutral Ph ◽  
Sepharose 4B ◽  
Derivatives Of

An improved, high-yield synthesis of the corresponding N-carboxypentyl derivatives of three iminoalditol glycosidase inhibitors has been developed for affinity chromatography enzyme purification. Reductive amination of 1-deoxynojirimycin (or its D-manno or D-galacto analogues) with methyl 5-formylvalerate and NaBH3CN at neutral pH afforted an aminoester which upon hydrolysis with aqueous 5% HCl gave the desired aminoacid in 97% overall yield. These amino acids could then be covalently attached using water-soluble carbodi-imide to 6-aminohexyl Sepharose 4B.

Highly γ-Regioselective 1,2-Addition of α,β-Unsaturated Oxime Ethers with Allylzinc Bromides: A Straightforward Approach for the Synthesis of Homoallylic Amines

Synthesis ◽  
2019 ◽  
Vol 51 (19) ◽  
pp. 3736-3746
Author(s):  
Bo Yang ◽  
Songlin Zhang
Keyword(s):  
Addition Reaction ◽  
Bond Formation ◽  
High Yield ◽  
Carbon Bond ◽  
Carbon Carbon Bond ◽  
Homoallylic Amines ◽  
One Step ◽  
The One ◽  
Straightforward Approach

A highly regioselective reaction between allylzinc bromide reagents and α,β-unsaturated oxime ethers for the one-step synthesis of the homoallylic amines is reported. This process is a regioselective 1,2-addition reaction providing a new γ-position with carbon–carbon bond formation. Furthermore, the reaction substrates are widely applicable and can be produced in a high yield.

scholarly journals Palladium- and copper-mediated N-aryl bond formation reactions for the synthesis of biological active compounds

2011 ◽  
Vol 7 ◽  
pp. 59-74 ◽  
Author(s):  
Carolin Fischer ◽  
Burkhard Koenig
Keyword(s):  
Large Scale ◽  
Standard Procedure ◽  
Bond Formation ◽  
Reaction Times ◽  
Biologically Active Compounds ◽  
Biologically Active ◽  
High Yield ◽  
Active Compounds ◽  
Advantages And Disadvantages ◽  
Ring Structures

N-Arylated aliphatic and aromatic amines are important substituents in many biologically active compounds. In the last few years, transition-metal-mediated N-aryl bond formation has become a standard procedure for the introduction of amines into aromatic systems. While N-arylation of simple aromatic halides by simple amines works with many of the described methods in high yield, the reactions may require detailed optimization if applied to the synthesis of complex molecules with additional functional groups, such as natural products or drugs. We discuss and compare in this review the three main N-arylation methods in their application to the synthesis of biologically active compounds: Palladium-catalysed Buchwald–Hartwig-type reactions, copper-mediated Ullmann-type and Chan–Lam-type N-arylation reactions. The discussed examples show that palladium-catalysed reactions are favoured for large-scale applications and tolerate sterically demanding substituents on the coupling partners better than Chan–Lam reactions. Chan–Lam N-arylations are particularly mild and do not require additional ligands, which facilitates the work-up. However, reaction times can be very long. Ullmann- and Buchwald–Hartwig-type methods have been used in intramolecular reactions, giving access to complex ring structures. All three N-arylation methods have specific advantages and disadvantages that should be considered when selecting the reaction conditions for a desired C–N bond formation in the course of a total synthesis or drug synthesis.

Mechanosynthesis of imine, β-ketoenamine, and hydrogen-bonded imine-linked covalent organic frameworks using liquid-assisted grinding

2014 ◽  
Vol 50 (84) ◽  
pp. 12615-12618 ◽  
Author(s):  
Gobinda Das ◽  
Digambar Balaji Shinde ◽  
Sharath Kandambeth ◽  
Bishnu P. Biswal ◽  
Rahul Banerjee
Keyword(s):  
Bond Formation ◽  
Covalent Bond ◽  
High Yield ◽  
Covalent Organic Frameworks ◽  
Covalent Bond Formation ◽  
Hydrogen Bonded

Dynamic covalent bond formation is dramatically accelerated under Liquid-Assisted Grinding (LAG) conditions leading to improved crystalline COFs efficiently at a faster rate and in high yield.

Sign in / Sign up

Export Citation Format

Share Document