scholarly journals Efficient synthesis of dihydropyrimidinones via a three-component Biginelli-type reaction of urea, alkylaldehyde and arylaldehyde

2013 ◽  
Vol 9 ◽  
pp. 2846-2851 ◽  
Author(s):  
Haijun Qu ◽  
Xuejian Li ◽  
Fan Mo ◽  
Xufeng Lin
Keyword(s):  
Molecular Iodine ◽  
Tandem Reaction ◽  
Efficient Synthesis ◽  
Reaction Conditions ◽  
One Pot ◽  
Type Reaction ◽  
Reaction Proceeds ◽  
Phosphoric Acids ◽  
Substituted Urea

A one-pot three-component synthesis of dihydropyrimidinones via a molecular iodine-catalyzed tandem reaction of simple readily available mono-substituted urea, alkylaldehyde, and arylaldehyde has been developed. The reaction proceeds with high chemo- and regioselectivity to give highly diverse dihydropyrimidinones in reasonable yields under mild reaction conditions. Moreover, the first catalytic enantioselective version of this reaction was also realized by using chiral spirocyclic SPINOL-phosphoric acids.

I2/DMSO-Promoted the synthesis of chromeno[4,3‑b]quinolines through an imine formation/aza-Diels-Alder/aromatization tandem reaction under metal-catalyst and photosensitizer-free conditions

Synthesis ◽  
2021 ◽  
Author(s):  
Angelica Peñaranda ◽  
Carlos Eduardo E. Puerto Galvis ◽  
Mario Alberto Macias ◽  
Cristian Ochoa-Puentes ◽  
Vladimir V. Kouznetsov
Keyword(s):  
Lewis Acid ◽  
Molecular Iodine ◽  
Diels Alder ◽  
Metal Catalyst ◽  
Tandem Reaction ◽  
Efficient Synthesis ◽  
Reaction Conditions ◽  
Heterocyclic Molecules ◽  
Dmso System ◽  
Tandem Process

A tandem approach was developed for the efficient synthesis of substituted chromeno[4,3-b]quinolines from arylamines and O-cinnamyloxy salicylaldehydes under metal-catalyst and photosensitizer-free reaction conditions. Our protocol is based on an inexpensive I2/DMSO system in which molecular iodine first acts as a Lewis acid to promote the formation of the corresponding imine bearing the alkene moiety, then, this species fulfills a second role by catalyzing the intramolecular aza-Diels-Alder cycloaddition to generate the respective tetrahydro-chromenoquinolines as an intermediates. Finally, the dual behaviour of DMSO as an oxidant and as a solvent resulted crucial at this stage, allowing the regeneration of I2 and promoting the aromatization of the tetrahydro-chromenoquinoline intermediates to yield the desired 7-aryl-6H-chromeno[4,3-b]quinolines. This protocol features by being mild, easy to perform, high step-economy (tandem process) and for providing a new access to biologically important nitrogen and oxygen containing heterocyclic molecules.

Visible-Light Photoredox-Catalyzed Cascade Reaction for the Synthesis of Pyrrolo[2,1-a]isoquinoline-Substituted Phosphonates

Synthesis ◽  
2018 ◽  
Vol 51 (02) ◽  
pp. 522-529 ◽  
Author(s):  
Deqing Shi ◽  
Lingna Wang ◽  
Tiancong Ma ◽  
Mingming Qiao ◽  
Qiangxian Wu ◽  
...  
Keyword(s):  
Visible Light ◽  
Visible Light Irradiation ◽  
Room Temperature ◽  
Cascade Reaction ◽  
Efficient Synthesis ◽  
Reaction Conditions ◽  
One Pot ◽  
Oxidative Aromatization ◽  
Activated Olefins ◽  
Catalyzed Oxidation

A visible-light photoredox-catalyzed oxidation/[3+2] cycloaddition/oxidative aromatization cascade reaction of [(3,4-dihydroisoquinolin-2(1H)-yl)methyl]phosphonates and activated olefins or alkynes for the efficient synthesis of potentially biological active pyrrolo[2,1-a]isoquinoline-substituted phosphonates was developed. This transformation features mild reaction conditions (i.e., visible light irradiation, room temperature), molecular oxygen (O2) as a green oxidant, simple ‘one-pot’ operation.

An Example of Ketone Olefination via Praseodymium-Mediated Barbier Reaction in the Presence of Diethyl Phosphite

Synlett ◽  
2019 ◽  
Vol 30 (12) ◽  
pp. 1437-1441
Author(s):  
Xu yan Cao ◽  
Fei Huang ◽  
Songlin Zhang
Keyword(s):  
Double Bond ◽  
Bond Formation ◽  
Point Of View ◽  
Diethyl Phosphite ◽  
Reaction Conditions ◽  
One Pot ◽  
Type Reaction ◽  
Mild Conditions ◽  
Allyl Halides ◽  
Barbier Reaction

The first example of carbon double-bond formation via praseodymium-mediated Barbier type reaction of ketones and allyl halides in the presence of diethyl phosphite is reported. The reaction is highly α-regioselective and conveniently carried out under mild conditions in a one-pot fashion. From a synthetic point of view, a series of conjugated alkenes were obtained in moderate to good yields in this one-pot reaction with practical reaction conditions.

Copper(II)-Promoted Oxidation/[3+2]Cycloaddition/Aromatization Cascade: Efficient Synthesis of Tetrasubstituted NH-Pyrrole from Chalcones and Iminodiacetates

Synlett ◽  
2019 ◽  
Vol 30 (12) ◽  
pp. 1442-1446 ◽  
Author(s):  
Zhang-qi Lin ◽  
Chao-dong Li ◽  
Zi-chun Zhou ◽  
Shuai Xue ◽  
Jian-rong Gao ◽  
...  
Keyword(s):  
Efficient Method ◽  
Cascade Reaction ◽  
Oxidative Cyclization ◽  
Efficient Synthesis ◽  
Reaction Conditions ◽  
Highly Efficient ◽  
Wide Range ◽  
Reaction Proceeds

A simple and highly efficient method for the preparation of tetrasubstituted NH-pyrrole from a wide range of chalcones and diethyl iminodiacetates via a Cu(OAc)2-promoted oxidation/[3+2]cycloaddition/aromatization cascade reaction has been developed. This reaction proceeds through dehydrogenations, deamination, and oxidative cyclization, affording the corresponding products in good to excellent yields. This convenient methodology for constructing tetrasubstituted NH-pyrroles has several advantages over existing methods, such as the use of easily accessible chalcones and readily available diethyl iminodiacetates, and mild reaction conditions. A wide range of substrates are tolerated.

One-pot atom-efficient synthesis of bio-renewable polyesters and cyclic carbonates through tandem catalysis

2015 ◽  
Vol 51 (40) ◽  
pp. 8504-8507 ◽  
Author(s):  
Fan Jia ◽  
Xiaoyu Chen ◽  
Yan Zheng ◽  
Yusheng Qin ◽  
Youhua Tao ◽  
...  
Keyword(s):  
Tandem Reaction ◽  
Cyclic Carbonates ◽  
Tandem Catalysis ◽  
Efficient Synthesis ◽  
One Pot ◽  
One Pot Synthesis ◽  
Salen Complexes ◽  
High Yields ◽  
First Time

One-pot synthesis of well-defined bio-renewable polyesters and cyclic carbonates in high yields was successfully realized for the first time by way of a tandem reaction using metal salen complexes as catalysts.

A chiral Brønsted acid-catalyzed highly enantioselective Mannich-type reaction of α-diazo esters with in situ generated N-acyl ketimines

2018 ◽  
Vol 54 (28) ◽  
pp. 3516-3519 ◽  
Author(s):  
Rajshekhar A. Unhale ◽  
Milon M. Sadhu ◽  
Sumit K. Ray ◽  
Rayhan G. Biswas ◽  
Vinod K. Singh
Keyword(s):  
Phosphoric Acid ◽  
Reaction Conditions ◽  
Type Reaction ◽  
Chiral Phosphoric Acid ◽  
Brönsted Acid ◽  
Diazo Esters ◽  
Reaction Proceeds ◽  
Acid Catalyzed ◽  
Chiral Bronsted Acid

A chiral phosphoric acid-catalyzed asymmetric Mannich-type reaction of α-diazo esters with in situ generated N-acyl ketimines, derived from 3-aryl-3-hydroxyisoindolinones has been demonstrated. The reaction proceeds smoothly under mild reaction conditions.

A one-pot synthesis of 2,2′-disubstituted diindolylmethanes (DIMs) via a sequential Sonogashira coupling and cycloisomerization/C3-functionalization of 2-iodoanilines

2017 ◽  
Vol 15 (33) ◽  
pp. 6997-7007 ◽  
Author(s):  
Anirban Kayet ◽  
Vinod K. Singh
Keyword(s):  
Sonogashira Coupling ◽  
Efficient Synthesis ◽  
Reaction Conditions ◽  
One Pot ◽  
Highly Efficient ◽  
One Pot Synthesis

Pd(ii)–Ag(i) catalysed, highly efficient synthesis of diindolylmethanes under mild reaction conditions, with six new bonds being formed in a one-pot fashion, and the products being transformed into synthetically useful compounds.

scholarly journals Palladium-catalyzed Heck-type reaction of secondary trifluoromethylated alkyl bromides

2017 ◽  
Vol 13 ◽  
pp. 2610-2616 ◽  
Author(s):  
Tao Fan ◽  
Wei-Dong Meng ◽  
Xingang Zhang
Keyword(s):  
Alkyl Radical ◽  
Functional Group ◽  
High Efficiency ◽  
Mechanistic Studies ◽  
Reaction Conditions ◽  
Type Reaction ◽  
Alkyl Bromides ◽  
Reaction Proceeds ◽  
Palladium Catalyzed ◽  
Hydroxy Groups

An efficient palladium-catalyzed Heck-type reaction of secondary trifluoromethylated alkyl bromides has been developed. The reaction proceeds under mild reaction conditions with high efficiency and excellent functional group tolerance, even towards formyl and hydroxy groups. Preliminary mechanistic studies reveal that a secondary trifluoromethylated alkyl radical is involved in the reaction.

Efficient Synthesis of Spirooxindole-Fused 3-Thiazoline Derivatives by a One-Pot Asinger-Type Reaction

Synlett ◽  
2016 ◽  
Vol 27 (20) ◽  
pp. 2831-2835 ◽  
Author(s):  
Alessandra Silvani ◽  
Giulia Rainoldi ◽  
Fabio Begnini ◽  
Giordano Lesma
Keyword(s):  
Efficient Synthesis ◽  
One Pot ◽  
Type Reaction

Nanofibre Sepiolite Catalyzed Green and Rapid Synthesis of 2-Amino-4H-chromene Derivatives

2018 ◽  
Vol 71 (1) ◽  
pp. 32 ◽  
Author(s):  
Arezou Mohammadinezhad ◽  
Batool Akhlaghinia
Keyword(s):  
Column Chromatography ◽  
Present Method ◽  
Simple Procedure ◽  
Reaction Times ◽  
Significant Decline ◽  
Efficient Synthesis ◽  
Reaction Conditions ◽  
Rapid Synthesis ◽  
One Pot ◽  
Highly Efficient

Nanofibre sepiolite catalyzed the rapid, clean, and highly efficient synthesis of 2-amino-4H-chromene derivatives by a one-pot, three-component condensation of a series of aldehydes, various enolizable C–H bonds (such as dimedone, α-naphthol, resorcinol, and 4-hydroxy-2H-chromen-2-one), and malononitrile in a mixture of water/ethanol. The present method offers several advantages such as high to excellent yields, short reaction times, mild reaction conditions, simple procedure, use of inexpensive, non-toxic, and naturally available catalyst, easy isolation of the products, and no need for column chromatography. The catalyst could be easily separated from the reaction mixture and can be reused for many consecutive trials without a significant decline in its reactivity.

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