Catalytic enantioselective cascade Michael/cyclization reaction of 3-isothiocyanato oxindoles with exocyclic α,β-unsaturated ketones en route to 3,2′-pyrrolidinyl bispirooxindoles

2016 ◽  
Vol 14 (43) ◽  
pp. 10175-10179 ◽  
Author(s):  
Satavisha Kayal ◽  
Santanu Mukherjee
Keyword(s):  
Cyclization Reaction ◽  
Cyclization Reactions ◽  
Unsaturated Ketones ◽  
Tertiary Amino

Cascade Michael/cyclization reactions between 3-isothiocyanato oxindoles and exocyclic α,β-unsaturated ketones are shown to proceed in the presence of a tertiary amino-squaramide catalyst and furnish 3,2′-pyrrolidinyl bispirooxindoles with excellent enantioselectivities (up to 99 : 1 er).

Triamide macrocyclic chloride receptors via a one-pot tandem reduction–condensation–cyclization reaction

2017 ◽  
Vol 15 (23) ◽  
pp. 4937-4940 ◽  
Author(s):  
Harekrushna Behera ◽  
Venkatachalam Ramkumar ◽  
Nandita Madhavan
Keyword(s):  
Cyclization Reaction ◽  
Chloride Binding ◽  
Cyclization Reactions ◽  
One Pot

A chloride binding triamide macrocycle has been developed in one pot from the corresponding monomer via tandem reduction–condensation–cyclization reactions.

scholarly journals Thiol-to-amine cyclization reaction enables screening of large libraries of macrocyclic compounds and the generation of sub-kilodalton ligands

2019 ◽  
Vol 5 (8) ◽  
pp. eaaw2851 ◽  
Author(s):  
S. S. Kale ◽  
M. Bergeron-Brlek ◽  
Y. Wu ◽  
M. G. Kumar ◽  
M. V. Pham ◽  
...  
Keyword(s):  
Drug Development ◽  
Structure Analysis ◽  
Drug Targets ◽  
Macrocyclic Ligands ◽  
Cyclization Reaction ◽  
Thrombin Inhibitor ◽  
Macrocyclic Compounds ◽  
Cyclization Reactions ◽  
X Ray ◽  
High Yields

Macrocyclic compounds are an attractive modality for drug development, but the limited availability of large, structurally diverse macrocyclic libraries hampers the discovery of leads. Here, we describe the discovery of efficient macrocyclization reactions based on thiol-to-amine ligations using bis-electrophiles, their application to synthesize and screen large libraries of macrocyclic compounds, and the identification of potent small macrocyclic ligands. The thiol-to-amine cyclization reactions showed unexpectedly high yields for a wide substrate range, which obviated product purification and enabled the generation and screening of an 8988 macrocycle library with a comparatively small effort. X-ray structure analysis of an identified thrombin inhibitor (Ki = 42 ± 5 nM) revealed a snug fit with the target, validating the strategy of screening large libraries with a high skeletal diversity. The approach provides a route for screening large sub-kilodalton macrocyclic libraries and may be applied to many challenging drug targets.

Facile synthesis of 2,3-benzodiazepines using one-pot two-step phosphate-assisted acylation–hydrazine cyclization reactions

2018 ◽  
Vol 16 (21) ◽  
pp. 4013-4020 ◽  
Author(s):  
Akinari Sumita ◽  
Jinhee Lee ◽  
Yuko Otani ◽  
Tomohiko Ohwada
Keyword(s):  
Cyclization Reaction ◽  
Cyclization Reactions ◽  
Acylation Reaction ◽  
Facile Synthesis ◽  
One Pot

We present a one-pot two-step methodology, in which an unprotected amino is tolerated, for rapidly synthesizing 2,3-benzodiazepines via phosphate-assisted acylation reaction and hydrazine cyclization reaction.

Iodine-mediated regioselective 5-endo-dig electrophilic cyclization reaction of selenoenynes: synthesis of selenophene derivatives

2017 ◽  
Vol 4 (2) ◽  
pp. 277-282 ◽  
Author(s):  
Renan P. Pistoia ◽  
Juliano A. Roehrs ◽  
Davi F. Back ◽  
Gilson Zeni
Keyword(s):  
Cyclization Reaction ◽  
Electrophilic Cyclization ◽  
Cyclization Reactions

Selenoenynes underwent electrophilic cyclization reactions with iodine in the presence of an appropriate nucleophile to give 3-iodo-selenophenes and 3-organoselenyl-selenophenes.

Kinetics and mechanism of base-catalyzed cyclization of substituted amides and nitriles of hydantoic acid

1987 ◽  
Vol 52 (1) ◽  
pp. 140-155 ◽  
Author(s):  
Vladimír Macháček ◽  
Gabriela Svobodová ◽  
Vojeslav Štěrba
Keyword(s):  
Rate Constant ◽  
Acid Amide ◽  
Phenyl Group ◽  
Reaction Rate Constant ◽  
Amide Group ◽  
Cyclization Reaction ◽  
Hydrolysis Rate ◽  
Cyclization Reactions ◽  
Hydrolysis Of ◽  
Derivatives Of

Rates of base-catalyzed cyclizations of 8 substituted derivatives of hydantoic acid amide type R3-NH(5)-CO(4)-NR2(3)-CH2(2)-CO(1)-NHR1 and 9 nitriles type R3-NH(5)-CO(4)-NR2(3)-CHR1(2)-CN have been measured in aqueous and methanolic media. The cyclization of the amides in aqueous medium is also accompanied by hydrolysis of the hydantoins formed. In some cases the hydrolysis rate constant is greater than the corresponding cyclization reaction rate constant. With the least reactive amides, the cyclization is also accompanied by hydrolysis of the amide group. The rate of the cyclization reactions in water is higher than that in methanol (at the same concentration of the lyate ions) by the factor of 10-100. Substitution of hydrogen at 3 and 5 positions by methyl or phenyl groups causes an acceleration of the cyclization reaction, whereas a substitution in the amide group causes a considerable retardation. The greatest acceleration of the cyclization (by as much as 4 orders) is caused by introduction of phenyl group to the N(5) position, which is due to a substantial increase of concentration of the reactive anion.

Addition-cyclization reactions of ethyl isothiocyanatoacetate with carboxylic acid hydrazides

1987 ◽  
Vol 52 (1) ◽  
pp. 113-119 ◽  
Author(s):  
Miroslav Veverka ◽  
Miroslav Marchalín
Keyword(s):  
Carboxylic Acid ◽  
Sodium Ethoxide ◽  
Cyclization Reaction ◽  
Thermal Cyclization ◽  
Cyclization Reactions ◽  
Effect Of Substituents

Ethyl (3-substituted 5-thioxo-1,2,4-triazolin-4-yl)acetates were prepared by addition-cyclization reaction of ethyl isothiocyanatoacetate with carboxylic acid hydrazides in the presence of sodium ethoxide. Thermal cyclization of the adduct in dimethylformamide afforded 1-acetamido-2-thiohydantoin. The effect of substituents on the cyclization course and the thione-thiol tautomerism are discussed.

Synthesis and cyclization reactions with pyrazolopyrimidinyl keto esters part I. Reactivity of pyrazolopyrimidinyl β-keto ester and pyrazolopyrimidinyl α,β-unsaturated ketones

2006 ◽  
Vol 60 (5) ◽  
Author(s):  
M. Awas
Keyword(s):  
Spectral Analysis ◽  
Biological Activity ◽  
Chemical Transformations ◽  
Cyclization Reactions ◽  
Keto Ester ◽  
Unsaturated Ketones ◽  
Keto Esters ◽  
Chemical Behaviour ◽  
Derivatives Of

Abstract5-Acetyl-4,5-dihydro-1-phenylpyrazolo[3,4-d]pyrimidin-4-one was prepared and subjected to various chemical transformations to give novel 5-heterocyclic pyrazolopyrimidinone derivatives of expected important biological activity. Then, the latter compounds were used to obtain β-keto ester and α,β-unsaturated carbonylpyrazolopyrimidinones which were used as alternate precursors to produce new pyrazolopyrimidinones substituted with five-membered heterocycles such as pyrazole and isoxazole. The structure of these compounds was identified on the basis of their chemical behaviour as well as elemental and spectral analysis.

scholarly journals Asymmetric Sequential Michael Addition and Cyclization Reactions of 2-(2-Nitrovinyl)phenols Catalyzed by Bifunctional Amino-Squaramides

SynOpen ◽  
2021 ◽  
Vol 05 (04) ◽  
pp. 278-284
Author(s):  
Radovan Šebesta ◽  
Eva Veverková ◽  
Pavlína Molnosiová
Keyword(s):  
Michael Addition ◽  
Cyclization Reaction ◽  
Side Chains ◽  
Green Solvents ◽  
Cyclization Reactions ◽  
Reaction Media ◽  
The Michael Addition

AbstractIn this work, we describe the Michael addition–cyclization reaction of 2-(2-nitrovinyl)phenol with two different reactive Michael donors, which lead to chiral benzopyran derivatives. Specifically, bifunctional amino-squaramides with one or two chiral units in the side chains were evaluated as catalysts in these transformations. Furthermore, the utility of selected green solvents as reaction media for these processes was also tested. The best result was achieved with methyl-cyclopentanone-2-carboxylate as the Michael donor in ethyl (–)-l-lactate with quinine-based amino-squaramide as catalyst (yield 72%, dr >99:1, ee 99%).

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