scholarly journals Solvent- and catalyst-free aza-Michael addition of imidazoles and related heterocycles

2020 ◽  
Author(s):  
Katharina Kodolitsch ◽  
Florian Gobec ◽  
Christian Slugovc
Keyword(s):  
Michael Addition ◽  
Catalyst Free ◽  
Michael Acceptor ◽  
Reaction Proceeds ◽  
Azole Derivative ◽  
Small Excess

This work demonstrates the scope and limitations of the aza-Michael addition of imidazoles and related heterocycles with electron deficient olefins under solvent- and catalyst-free conditions. The reaction proceeds at 80°C within hours towards completion as long as the azole derivative is sufficiently soluble in the Michael acceptor, which has been used in small excess. Workup only comprises evaporation of surplus Michael-acceptor and no additional solvents are necessary for purifying the products.<br>

scholarly journals Solvent- and catalyst-free aza-Michael addition of imidazoles and related heterocycles

2020 ◽  
Author(s):  
Katharina Kodolitsch ◽  
Florian Gobec ◽  
Christian Slugovc
Keyword(s):  
Michael Addition ◽  
Catalyst Free ◽  
Michael Acceptor ◽  
Reaction Proceeds ◽  
Azole Derivative ◽  
Small Excess

This work demonstrates the scope and limitations of the aza-Michael addition of imidazoles and related heterocycles with electron deficient olefins under solvent- and catalyst-free conditions. The reaction proceeds at 80°C within hours towards completion as long as the azole derivative is sufficiently soluble in the Michael acceptor, which has been used in small excess. Workup only comprises evaporation of surplus Michael-acceptor and no additional solvents are necessary for purifying the products.<br>

scholarly journals Solvent- and catalyst-free aza-Michael addition of imidazoles and related heterocycles

2020 ◽  
Author(s):  
Katharina Kodolitsch ◽  
Florian Gobec ◽  
Christian Slugovc
Keyword(s):  
Michael Addition ◽  
Catalyst Free ◽  
Michael Acceptor ◽  
Reaction Proceeds ◽  
Azole Derivative ◽  
Small Excess

This work demonstrates the scope and limitations of the aza-Michael addition of imidazoles and related heterocycles with electron deficient olefins under solvent- and catalyst-free conditions. The reaction proceeds at 80°C within hours towards completion as long as the azole derivative is sufficiently soluble in the Michael acceptor, which has been used in small excess. Workup only comprises evaporation of surplus Michael-acceptor and no additional solvents are necessary for purifying the products.<br>

Diversity-Oriented Synthesis via Catalyst-Free Addition of Ketones to [e]-Fused 1H-Pyrrole-2,3-diones

Synthesis ◽  
2018 ◽  
Vol 50 (24) ◽  
pp. 4897-4904 ◽  
Author(s):  
Ekaterina Stepanova ◽  
Andrey Maslivets ◽  
Svetlana Kasatkina ◽  
Maksim Dmitriev
Keyword(s):  
Intramolecular Cyclization ◽  
Aromatic Hydrocarbons ◽  
Michael Addition ◽  
Aldol Reaction ◽  
Synthetic Approach ◽  
Reaction Conditions ◽  
Diversity Oriented Synthesis ◽  
Catalyst Free ◽  
Solvent Free Conditions ◽  
Reaction Proceeds

A facile synthetic approach towards two distinct pyrrole-based heterocyclic scaffolds has been developed by the interaction of 1H-pyrrole-2,3-diones fused at the [e]-side to a 1,4-benzoxazin-2-one or quinoxalin-2(1H)-one moiety with ketones. The described interaction proceeds either as an aldol reaction or as a Michael addition/intramolecular cyclization depending on the reaction conditions. The disclosed aldol reaction proceeds with good diastereoselectivity under catalyst-free conditions when the reaction is carried out in aromatic hydrocarbons. Products of the cascade Michael addition/intramolecular cyclization reaction are predominantly formed under catalyst-free and solvent-free conditions. The proposed strategy provides facile access to pharmaceutically interesting pyrrole-based polyheterocycles.

Tandem Alkylation/Michael Addition Reaction of Dithiocarbamic Acids with Alkyl γ-Bromocrotonates: Access to Functionalized 1,3-Thiazolidine-2-thiones

Synthesis ◽  
2021 ◽  
Author(s):  
Azim Ziyaei Halimehjani ◽  
Petr Beier ◽  
Maryam Khalili Foumeshi ◽  
Ali Alaei ◽  
Blanka Klepetářová
Keyword(s):  
Amino Acids ◽  
Carbon Disulfide ◽  
Multicomponent Reaction ◽  
Michael Addition ◽  
Addition Reaction ◽  
Primary Amines ◽  
Oxidation Reactions ◽  
Michael Addition Reaction ◽  
Synthetic Utility ◽  
Reaction Proceeds

AbstractThiazolidine-2-thiones were prepared via a novel multicomponent reaction of primary amines (amino acids), carbon disulfide, and γ-bromocrotonates. The reaction proceeds via a domino alkylation/intramolecular Michael addition to provide the corresponding thiazolidine-2-thiones in high to excellent yields. By using diamines in this protocol, bis(thiazolidine-2-thiones) derivatives were synthesized. The synthetic utility of the adducts was demonstrated by hydrolysis, amidation, and oxidation reactions.

Catalyst-Free One-Pot Synthesis of Novel Heteroarylamine Substituted Furo[3,2-c]coumarins

Synlett ◽  
2018 ◽  
Vol 29 (12) ◽  
pp. 1589-1592 ◽  
Author(s):  
Abolfazl Olyaei ◽  
Mahnaz Saraei ◽  
Reyhaneh Khoeiniha
Keyword(s):  
Michael Addition ◽  
Aldol Condensation ◽  
Ring Closure ◽  
Dehydration Reaction ◽  
One Pot ◽  
Catalyst Free ◽  
One Pot Synthesis ◽  
Tandem Process ◽  
First Time

A high-yielding cyclocondensation of 4-hydroxycoumarin, phenylglyoxal monohydrate, and heteroarylamines proceeds without catalysis, which gives novel functionalized furo[3,2-c]coumarins and heteroarylamino alkylation of coumarin products in acetonitrile under reflux, is reported for the first time. This tandem process involves sequentially an aldol condensation, Michael addition, a ring closure, and dehydration reaction.

Base and catalyst-free synthesis of nitrobenzodiazepines via a cascade N-nitroallylation-intramolecular aza-Michael addition involving o-phenylenediamines and nitroallylic acetates

Tetrahedron ◽  
2019 ◽  
Vol 75 (51) ◽  
pp. 130761 ◽  
Author(s):  
Divya K. Nair ◽  
Sudheesh T. Sivanandan ◽  
Pravin Kendrekar ◽  
Irishi N.N. Namboothiri
Keyword(s):  
Michael Addition ◽  
Catalyst Free

scholarly journals Hydroalkynylative cyclization of 1,6-enynes with terminal alkynes

2019 ◽  
Vol 10 (28) ◽  
pp. 6863-6867 ◽  
Author(s):  
Qi Teng ◽  
Nuligonda Thirupathi ◽  
Chen-Ho Tung ◽  
Zhenghu Xu
Keyword(s):  
Symmetry Breaking ◽  
Michael Addition ◽  
Terminal Alkynes ◽  
Reaction Proceeds

A rhodium-catalyzed highly regio- and enantioselective hydroalkynylation generating cis-hydrobenzofuranone-tethered enynes has been developed. The reaction proceeds with a dynamic kinetic head-to-head insertion and symmetry breaking Michael addition cascade.

Catalyst-Free Synthesis of Chromane-Type N,O-Acetals via Intramolecular Addition of Phenols to Enamines

Synthesis ◽  
2020 ◽  
Vol 52 (23) ◽  
pp. 3604-3621 ◽  
Author(s):  
Vitaly A. Osyanin ◽  
Dmitry V. Osipov ◽  
Irina V. Melnikova ◽  
Kirill S. Korzhenko ◽  
Irina A. Semenova ◽  
...  
Keyword(s):  
Cascade Reaction ◽  
Secondary Amines ◽  
Catalyst Free ◽  
Reaction Proceeds ◽  
New Strategy

A new strategy to 2-aminochromanes through catalyst-free cascade reaction of 3-trifluoroacetyl-4H-chromenes and 4H-chromene-3-carbaldehydes with cyclic secondary amines is presented. The reaction proceeds through subsequent 1,4- and 1,2-additions of amine, bimolecular elimination of trifluoroacetamide or formamide, and 6-exo-trig cyclization. The latter stage is a very rare example of addition of phenols to enamines. The obtained semicyclic N,O-acetals were applied as useful precursors for the synthesis of other chromanes.

tert-Butyl nitrite promoted transamidation of secondary amides under metal and catalyst free conditions

2019 ◽  
Vol 17 (4) ◽  
pp. 845-850 ◽  
Author(s):  
Popuri Sureshbabu ◽  
Sadaf Azeez ◽  
Priyanka Chaudhary ◽  
Jeyakumar Kandasamy
Keyword(s):  
Tert Butyl ◽  
Catalyst Free ◽  
Reaction Proceeds ◽  
Secondary Amides

Transamidation of secondary amides with various amines is demonstrated using tert-butyl nitrite. The reaction proceeds through the N-nitrosamide intermediate and provides the desired products in excellent yields.

scholarly journals Substrate-controlled Diastereoselective Michael Addition of Alkylidene Malonates by Grignard Reagents

2019 ◽  
Vol 25 (1) ◽  
pp. 116-121
Author(s):  
Wei Zhou ◽  
Qingwei Xiao ◽  
Yuanyuan Chang ◽  
Qifa Liu ◽  
Xiaohao Zang ◽  
...  
Keyword(s):  
Amino Acid ◽  
Asymmetric Synthesis ◽  
Michael Addition ◽  
Chiral Auxiliary ◽  
Grignard Reagents ◽  
Amino Acid Derivatives ◽  
Catalyst Free ◽  
Chemical Efficiency

AbstractHerein is described a diastereoselective Michael addition of Grignard reagents to α, β- unsaturated diethyl malonates incorporated with a 2-oxazolidone chiral auxiliary. The catalyst-free Michael addition proceeds with good chemical efficiency and excellent stereoselectivity; and it provides new thoughts to the asymmetric synthesis of β-substituted β3 amino acid derivatives.

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