Lewis Acid Catalyzed Regio- and Diastereoselective Synthesis of Spiroisoxazolines via One-Pot Sequential Knoevenagel Condensation/1,3-Dipolar Cycloaddition Reaction

Synthesis ◽  
2019 ◽  
Vol 51 (07) ◽  
pp. 1669-1679 ◽  
Author(s):  
Ayoob Bazgir ◽  
Hossein Yazdani

A ZnCl2-catalyzed regio- and diastereoselective one-pot sequential Knoevenagel condensation/1,3-dipolar cycloaddition reaction of CH acids (oxindole, 1,3-indandione, and 3H-pyrazol-3-one), aldehydes, and dibromoformaldoxime has been established. The method allows the synthesis of diversely functionalized spiroisoxazolines in good isolated yields under mild reaction conditions. Moreover, the preparation of spiroindene-isoxazole-1,3-diones containing benzoimidazole or benzothiazole moieties as new ligands for the metal-catalyzed coupling reactions and C–H activation is demonstrated.

Synlett ◽  
2019 ◽  
Vol 31 (03) ◽  
pp. 267-271 ◽  
Author(s):  
Firouz Matloubi Moghaddam ◽  
Atiyeh Moafi ◽  
Behzad Jafari ◽  
Alexander Vilinger ◽  
Peter Langer

A regio- and diastereoselective synthesis of 2,3-dihydro-10b′H-spiro[indeno[1,2-b]quinoxaline-11,1′-pyrrolo[2,1-a]isoquinoline]-2′,3′-diylbis(phenylmethanone) derivatives containing four contiguous chiral stereocenters was achieved through 1,3-dipolar cycloaddition of isoquinolinium N-ylides in a one-pot three-component reaction. The desired products were obtained in short reaction times and in moderate to high yields (up to 92%) under relatively mild reaction conditions. The structure and relative stereochemistry of the desired product was confirmed by X-ray diffraction analysis.


2014 ◽  
Vol 16 (9) ◽  
pp. 466-477 ◽  
Author(s):  
Ram Awatar Maurya ◽  
Praveen Reddy Adiyala ◽  
D. Chandrasekhar ◽  
Chada Narsimha Reddy ◽  
Jeevak Sopanrao Kapure ◽  
...  

Author(s):  
Elisabeth Sitte ◽  
Brendan Twamley ◽  
nitika grover ◽  
Mathias Senge

The bicyclo[1.1.1]pentane (BCP) unit exhibits special physical and chemical properties and is under scrutiny as a bioisostere in drug molecules. We employed methodologies for the synthesis of different BCP triazole building blocks from one precursor, 1-azido-3-iodobicyclo[1.1.1]pentane, by Cu(I)-catalyzed 1,3-dipolar cycloaddition (“click”) reactions and integrated cycloaddition-Sonogashira coupling reactions. Thereby, we accessed three classes of substituted BCP derivatives: 1,4-disubstituted triazoles, 5-iodo-1,4,5-trisubstituted triazoles and 5-alkynylated 1,4,5-trisubstituted triazoles. This gives entry to the synthesis of multiply substituted BCP triazoles either on a modular or a one-pot basis. These methodologies were further utilized for appending large chromophoric porphyrin moieties onto the BCP core.


2020 ◽  
Author(s):  
Elisabeth Sitte ◽  
Brendan Twamley ◽  
nitika grover ◽  
Mathias Senge

The bicyclo[1.1.1]pentane (BCP) unit exhibits special physical and chemical properties and is under scrutiny as a bioisostere in drug molecules. We employed methodologies for the synthesis of different BCP triazole building blocks from one precursor, 1-azido-3-iodobicyclo[1.1.1]pentane, by Cu(I)-catalyzed 1,3-dipolar cycloaddition (“click”) reactions and integrated cycloaddition-Sonogashira coupling reactions. Thereby, we accessed three classes of substituted BCP derivatives: 1,4-disubstituted triazoles, 5-iodo-1,4,5-trisubstituted triazoles and 5-alkynylated 1,4,5-trisubstituted triazoles. This gives entry to the synthesis of multiply substituted BCP triazoles either on a modular or a one-pot basis. These methodologies were further utilized for appending large chromophoric porphyrin moieties onto the BCP core.


2019 ◽  
Vol 23 (16) ◽  
pp. 1778-1788 ◽  
Author(s):  
Gurpreet Kaur ◽  
Arvind Singh ◽  
Kiran Bala ◽  
Mamta Devi ◽  
Anjana Kumari ◽  
...  

A simple, straightforward and efficient method has been developed for the synthesis of (E)-3-(arylimino)indolin-2-one derivatives and (E)-2-((4-methoxyphenyl)imino)- acenaphthylen-1(2H)-one. The synthesis of these biologically-significant scaffolds was achieved from the reactions of various substituted anilines and isatins or acenaphthaquinone, respectively, using commercially available, environmentally benign and naturally occurring organic acids such as mandelic acid or itaconic acid as catalyst in aqueous medium at room temperature. Mild reaction conditions, energy efficiency, good to excellent yields, environmentally benign conditions, easy isolation of products, no need of column chromatographic separation and the reusability of reaction media are some of the significant features of the present protocol.


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