Bifunctional squaramide catalyzed stereoselective Mannich reaction of α-azido ketones with isatin-derived ketimines

2020 ◽  
Vol 18 (3) ◽  
pp. 479-487 ◽  
Author(s):  
Seda Karahan ◽  
Cihangir Tanyeli
Keyword(s):  
Mannich Reaction ◽  
Optically Active ◽  
First Time ◽  
High Stereoselectivity

Bifunctional squaramide catalyzed asymmetric Mannich reaction of alpha-azido ketones and isatin derived ketiminines were established for the first time with high stereoselectivity. Adducts are valuable synthons for optically active heterocycles.

scholarly journals Broad scope gold(i)-catalysed polyenyne cyclisations for the formation of up to four carbon–carbon bonds

2017 ◽  
Vol 15 (10) ◽  
pp. 2163-2167 ◽  
Author(s):  
Zhouting Rong ◽  
Antonio M. Echavarren
Keyword(s):  
Single Step ◽  
Simultaneous Formation ◽  
Broad Scope ◽  
Carbon Carbon Bonds ◽  
Carbon Bonds ◽  
First Time ◽  
High Stereoselectivity

The polycyclisation of polyeneynes catalyzed by gold(i) has been extended for the first time to the simultaneous formation of up to four carbon–carbon bonds, leading to steroid-like molecules with high stereoselectivity in a single step with low catalyst loadings.

Thermal rearrangement of optically active tetradeuterated 2-methoxymethyl-methylenecyclopropane and the bent bond/antiperiplanar hypothesis

2019 ◽  
Vol 17 (29) ◽  
pp. 7007-7012 ◽  
Author(s):  
Ghislain Deslongchamps ◽  
Pierre Deslongchamps
Keyword(s):  
Mechanistic Model ◽  
Optically Active ◽  
Thermal Rearrangement ◽  
First Time

The bent bond/antiperiplanar hypothesis (BBAH) provides, for the first time, a mechanistic model that rationalizes methylenecyclopropane rearrangements.

A Highly Diastereoselective Decarboxylative Mannich Reaction of β-Keto Acids with Optically Active N-Sulfinyl α-Imino Esters

2012 ◽  
Vol 14 (12) ◽  
pp. 3092-3095 ◽  
Author(s):  
Cui-Feng Yang ◽  
Chen Shen ◽  
Jian-Yong Wang ◽  
Shi-Kai Tian
Keyword(s):  
Mannich Reaction ◽  
Optically Active ◽  
Keto Acids ◽  
Imino Esters

Enantioselective construction of imidazolines having vicinal tetra-substituted stereocenters by direct Mannich reaction of α-substituted α-isocyanoacetates with ketimines

2016 ◽  
Vol 52 (47) ◽  
pp. 7462-7465 ◽  
Author(s):  
Shuichi Nakamura ◽  
Ryota Yamaji ◽  
Masaru Iwanaga
Keyword(s):  
Mannich Reaction ◽  
Type Reaction ◽  
High Stereoselectivity

Enantioselective direct Mannich-type reaction of ketimines with α-substituted α-isocyanoacetates gave imidazolines having vicinal tetra-substituted stereocenters with high stereoselectivity.

scholarly journals Biocatalyzed Sulfoxidation in Presence of Deep Eutectic Solvents

2020 ◽  
Vol 1 (3) ◽  
pp. 290-297
Author(s):  
Gonzalo de Gonzalo
Keyword(s):  
Deep Eutectic Solvents ◽  
Optically Active ◽  
Cofactor Regeneration ◽  
Natural Deep Eutectic Solvents ◽  
Phosphite Dehydrogenase ◽  
Valuable Compounds ◽  
First Time ◽  
Substrate Concentrations

The flavin-containing monooxygenase from Methylophaga sp. strain SK1 (mFMO) is a valuable biocatalyst for the preparation of optically active sulfoxides, among other valuable compounds. In this study, we explored to benefits of using Natural Deep Eutectic Solvents (NADESs) when doing oxidation with this biocatalyst, fused to phosphite dehydrogenase for cofactor regeneration (PTDH-mFMO). It was found that optically active sulfoxides could be obtained with slightly higher conversions in 10% v/v NADES when working at substrate concentrations of 50–200 mM, whereas there was no loss in the enantioselectivity. With these results, it is demonstrated for the first time that flavin-containing monooxygenases can be employed as biocatalysts in presence of NADESs.

Synthesis, Transformations and Characterization of 8 Aminomethyl Substituted Umbelliferones as Probable Anti-Arrhythmic Agents

2019 ◽  
Vol 15 (1) ◽  
pp. 71-82 ◽  
Author(s):  
Alla V. Lipeeva ◽  
Arkady O. Brysgalov ◽  
Tatyana G. Tolstikova ◽  
Elvira E. Shults
Keyword(s):  
Mannich Reaction ◽  
Suzuki Reaction ◽  
Mannich Bases ◽  
Pharmacological Agents ◽  
Natural Coumarin ◽  
The Mannich Reaction ◽  
First Time ◽  
Substituted Coumarins

Background: Coumarin and modified nitrogen heterocyclic nuclei show biological activity. Combining these into a hybrid molecule could lead to new pharmacological agents. A series of hybrid compounds combining coumarin and piperidine, piperazine, purine or tetrahydroisoquinoline moieties were synthesized and evaluated for anti-arrhythmic activity. Methods: The Mannich reaction of coumarins (peurutenicin, peucenol and 6-cyanoumbelliferrone) with formaldehyde and various amines, including several alkaloids – anabasine, theophylline or tetrahydroisoquinolines, proceeds by heating under reflux in dioxane in the presence of 4-dimethylaminopyridine. The Suzuki reaction of 6,8-disubstituted umbelliferone triflate was used for the introduction of an aryl substituent in position 7 of the the coumarin framework. Results: Twenty two novel coumarin-based Mannich bases were synthesized via introduction of functional aminomethyl group at position 8 of 6 substituted 7-hydroxy-2H-chromen-2-ones by Mannich reaction. The results illustrated that the C-6 and C-8 substituents’ effect was obvious in our designed system and there was a relationship between the structures and the anti-arrhythmic activity of the 6,7,8- trisubstituted coumarins. 8-(6,7-dimethoxy-1-(3,4,5-trimethoxyphenyl)-tetrahydroisoquinolinylmethyl)- substituted peucenol derivatives shown in vivo a pronounced and selective anti-arrhythmic activity on epinephrine arrhythmias in comparison with natural coumarin peucenol. The moderate toxicity of the new compound encouraged further design of therapeutically relevant analogues based on this novel type of coumarin- tetrahydroisoquinoline hybrids. Conclusion: We have developed a mild reaction protocol to synthesize new mannich products on the basis of substituted coumarins. The anti-arrhythmic activity of coumarin-tetrahydroisoquinoline hybrids was revealed. We report for the first time that coumarin containing 8-(1-(3,4,5-trimethoxyphenyl) tetrahydroisoquinolinyl)methyl) substituent offer a suitable scaffold for the development of novel anti-arrhythmic agents.

Studien zum Vorgang der Wasserstoffübertragung, 72 [1] Versuche zur enantioselektiven Homogenhydrierung von N-Acyl-α-aminozimtsäuren mit Rh(I)-Komplexen unter Verwendung neuer optisch aktiver Co-Katalysatoren/Studies on the Occurrence of Hydrogen Transfer, 72, [1] Investigation on the Enantioselective Homogeneous Hydrogenation of N-Acyl-α-aminocinnamic Acids with Rh(I)-Complexes Using New Optically Active Co-Catalysts

1984 ◽  
Vol 39 (4) ◽  
pp. 512-516 ◽  
Author(s):  
L. Horner ◽  
G. Simons
Keyword(s):  
Hydrogen Transfer ◽  
Optically Active ◽  
Type I ◽  
Type Ii ◽  
Homogeneous Hydrogenation ◽  
Active Compounds ◽  
Co Catalyst ◽  
Co Catalysts ◽  
Optical Induction ◽  
First Time

3 Optically active compounds of the type I and 15 optically active compounds of the type II were investigated as co-catalysts in the homogeneous hydrogenation of N-acyl-α-aminocinnamic acids using standard conditions. In the co-catalysts of the type I the phosphorus atom is the center of the asymmetry. In the representatives of type II the side chain is optically active and the three bonded phosphorus either achiral or optically active.The results of the homogeneous hydrogenation are deposited in the Tables I-IV. In the Tables I and IV the degree of the optical induction and the configuration of the excess enantiomer are determined using Rh/P-ratios 1:1,1 and 1:2,2. The Tables II and III show the results applying a Rh/P-ratio of 1:2,2. The observed degree of optical induction is low with the co-catalysts 1-18; only the co-catalyst 19 shows an optical induction of 68%. A change of the configuration of the excess enantiomer of N-benzoylphenylalanine formed by the homogeneous hydrogenation of N-benzoyl-α-cinnamic acid for the first time was observed by varying the Rh/P-ratio of the co-catalysts 14, 17 and 18 from 1:1,1 to 1:2,2.

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