Cycloaddition Reaction Of Azomethine Ylides Research Articles

Highly Efficient Construction of Sugar-Fused Spirochromanono Pyrrolidines/Pyrrolizidines/Thiolizidines via 1,3-Dipolar Cycloaddition of Azomethine Ylides

A variety of sugar-fused chromanono pyrrolidines/pyrrolizidines/thiolizidines have been synthesized by intermolecular 1,3-dipolar cycloaddition reaction of azomethine ylides (generated from glucose aldehyde and different secondary amino acids) with various 3-arylidene chroman-4-ones as dipolarophiles. The solvent effect on the 1,3-dipolar cycloaddition reaction is also studied.

A synthesis of functionalized dihydro-1Η-pyrrolizines and spiropyrrolizines via [2 + 3] cycloaddition reactions.

A one-pot synthesis of dihydro-1H-pyrrolizine derivatives via [Formula: see text] cycloaddition reaction of azomethine ylides, prepared in situ from proline and ninhydrin, with dialkyl acetylenedicarboxylates, in alcohols, is described. When sarcosine was used instead of proline, functionalized spiropyrrolizines were obtained. Under these conditions, alkyl propiolates produced stable spirans.

Regio- and stereoselective synthesis of novel trispiropyrrolidine/thiapyrrolizidines using deep eutectic solvent as an efficient reaction media

An efficient synthesis of novel trispiropyrrolidine/thiapyrrolizidines has been reported by the 1,3-dipolar cycloaddition reaction of azomethine ylides with a novel dipolarophile 8,10-bis[(E)arylidene]-3,3-dimethyl-1,5-dioxaspiro[5.5]undecan-9-one using deep eutectic solvent (DES). The DES is cheaper, biodegradable, non-toxic, recyclable and serves as dual role of catalyst as well as solvent. The suitable azomethine ylides were generated ‘in situ’ from the reaction of substituted isatin/acenaphthenequinone and sarcosine/1,3-thiazolane-4-carboxylic acid. In this protocol generation of one new five-membered pyrrolidine ring with three contiguous stereocenters occurred in a single operation. The stereochemistry of the synthesized compounds including regio- and diastereo was confirmed by spectroscopic techniques and single-crystal X-ray of one representative compound.

A synthesis of fused acenaphthopyrrolizines via the 1,3-dipolar cycloaddition reaction of azomethine ylides with acetylenic esters.

An efficient synthesis of tetraalkyl 6a-hydroxy-3-alkyl-3H,6aH-acenaphtho[1,2-g] pyrrolizine-1,2,5,6-tetracarboxylates via the 1,3-dipolar cycloaddition reaction of azomethine ylides (generated in situ from [Formula: see text]-amino acids and acenaphthylene-1,2-dione) with dialkyl acetylenedicarboxylates is described. When glycine was used instead of alanine, phenylalanine, valine, or isoleucine, dialkyl (E)-1[Formula: see text]-(1,4-dialkoxy-1,4-dioxobut-2-en-2-yl)-2-oxo-[Formula: see text],5[Formula: see text]-dihydro-2H-spiro [acenaphthylene-1,2[Formula: see text]-pyrrole]-3[Formula: see text],4[Formula: see text]-dicarboxylates were obtained. The steric effects of the [Formula: see text]-amino acids side chains may be responsible for their different behaviors.

Alkenyl Arenes as Dipolarophiles in Catalytic Asymmetric 1,3-Dipolar Cycloaddition Reactions of Azomethine Ylides.

The use of alkenyl arenes as dipolarophiles in the catalytic asymmetric 1,3-dipolar cycloaddition of azomethine ylides is reported. Under appropriate reaction conditions with a CuI or AgI catalyst either the exo or the endo adduct was obtained with high stereoselectivity. This process provides efficient access to highly enantiomerically enriched 4-aryl proline derivatives. The observed results are compatible with the blockage of one prochiral face of the 1,3-dipole, as well as with the efficient transmission of electrophilicity towards the terminal carbon atom of the dipolarophile. This polarization results in a change from a concerted to a stepwise mechanism.

Alkenyl Arenes as Dipolarophiles in Catalytic Asymmetric 1,3‐Dipolar Cycloaddition Reactions of Azomethine Ylides

AbstractThe use of alkenyl arenes as dipolarophiles in the catalytic asymmetric 1,3‐dipolar cycloaddition of azomethine ylides is reported. Under appropriate reaction conditions with a CuI or AgI catalyst either the exo or the endo adduct was obtained with high stereoselectivity. This process provides efficient access to highly enantiomerically enriched 4‐aryl proline derivatives. The observed results are compatible with the blockage of one prochiral face of the 1,3‐dipole, as well as with the efficient transmission of electrophilicity towards the terminal carbon atom of the dipolarophile. This polarization results in a change from a concerted to a stepwise mechanism.

Synthesis of first ever 4-quinolone-3-carboxylic acid-appended spirooxindole-pyrrolidine derivatives and their biological applications.

A series of 4-quinolone-3-carboxylic acid-containing spirooxindole-pyrrolidine derivatives was synthesized via multicomponent 1,3-dipolar cycloaddition reactions of azomethine ylides with new (E)-4-oxo-6-(3-phenyl-acryloyl)-1,4-dihydroquinoline-3-carboxylic acids in good yields with high regioselectivity. The cycloadducts were characterized by analytical and spectral data including [Formula: see text], [Formula: see text], 2D NMR and mass spectroscopy. The structure of one of the compounds (8a) was investigated theoretically by computational techniques. DFT studies support the proposed mechanism for this cycloaddition reaction. Furthermore, antibacterial activities of the new compounds were evaluated against Gram-positive and Gram-negative bacterial strains. Compounds 8f, 8m and 8p showed potent inhibition activities against selected bacteria. The in vitro cytotoxicity of spirooxindole derivatives (8a-r) was evaluated against MCF-7 breast cancer cell line. Among the various compounds tested, compound 8f [Formula: see text] showed significant cytotoxic activity compared to the standard drug doxorubicin [Formula: see text].

ChemInform Abstract: Diastereo‐ and Enantioselective Copper(I)‐Catalyzed Intermolecular [3 + 2] Cycloaddition of Azomethine Ylides with β‐Trifluoromethyl β,β‐Disubstituted Enones.

Reported herein is an asymmetric [3+2] cycloaddition reaction of azomethine ylides with β-trifluoromethyl β,β-disubstituted enones, a reaction which is enabled by a Ming-Phos-derived copper(I) catalyst (Ming-Phos=chiral sulfinamide monophosphines, Figure 1). This method provides scalable and efficient access to the highly substituted pyrrolidines with a trifluoromethylated, all-carbon quaternary stereocenter in good yields with up to greater than 20:1 d.r. and 98 % ee. The reaction has a broad substrate scope and tolerates a wide range of functional groups.

ChemInform Abstract: Highly Efficient and Regioselective Synthesis of Spirooxindolo Pyrrolizidines by Reaction of Isatin, Proline and Acrylonitrile/Methyl Acrylate in Water.

AbstractThe 1,3‐dipolar cycloaddition reaction of azomethine ylides generated in situ by isatin and L‐proline to acrylonitrile and methyl acrylate in water affords a series of spirooxindolo pyrrolizidines in good yields.

1,3-Dipolar Cycloaddition Reactions of Azomethine Ylides with Carbonyl Dipolarophiles Yielding Oxazolidine Derivatives.

We provide a comprehensive account of the 1,3-dipolar cycloaddition reactions of azomethine ylides with carbonyl dipolarophiles. Many different azomethine ylides have been studied, including stabilized and non-stabilized ylides. Of the carbonyl dipolarophiles, aldehydes including formaldehyde are the most studied, although there are now examples of cycloadditions with ketones, ketenes and carboxyl systems, in particular isatoic anhydrides and phthalic anhydrides. Intramolecular cycloadditions with esters can also occur under certain circumstances. The oxazolidine cycloadducts undergo a range of reactions triggered by the ring-opening of the oxazolidine ring system.

Regio- and diastereoselective construction of a new set of functionalized pyrrolidine, spiropyrrolidine and spiropyrrolizidine scaffolds appended with aryl- and heteroaryl moieties via the azomethine ylide cycloadditions

Highly regio- and diastereoselective syntheses of a new set of functionalized pyrrolidines, spiro-pyrrolidine/pyrrolizidine oxindoles, spiroacenaphthylenolyl-pyrrolidines/pyrrolizidines and spiro-1,3-indandionolyl-pyrrolidines/pyrrolizidines appended with various aryl- and heteroaryl moieties via the azomethine ylide cycloaddition reaction are reported. The Ag-catalyzed [3+2] cycloaddition of azomethine ylides derived from N-benzylideneiminoglycinates with various arylidene/heteroarylidenemalononitriles gave C-3,C-5-aryl/heteroaryl substituted C-4,C-4-dicyanopyrrolidine-2-carboxylate scaffolds with good regio- and diastereoselectivity. Further, the [3+2] cycloaddition of azomethine ylides derived from the decarboxylative reactions of different 1,2-dicarbonyls and α-amino acids with the indole/pyrrole-based dipolarophiles were investigated. In the context of enriching the library of functionalized spiropyrrolidine- and spiropyrrolizidine scaffolds, these reactions have led to the assembling of various spiro-pyrrolidine/pyrrolizidine oxindoles, spiroacenaphthylenolyl-pyrrolidines/pyrrolizidines and spiro-1,3-indandionolyl-pyrrolidines/pyrrolizidines appended with the indolyl- and pyrrolyl moieties at the C-3 position of the spiro-pyrrolidine/pyrrolizidine rings. The stereochemistry of the cycloadducts was assigned based on the single crystal X-ray structures of representative major diastereomers 8c, 8d, 9b, 9c, 17a, 17b, 17c, 18a, 18e and 19a obtained from the azomethine ylide cycloaddition reactions.

REGIOSPECIFIC SYNTHESIS AND RATIONALIZATION OF THE REGIODIVERGENCE SOME SPIROOXINDOLES AS EXPECTED ANTIOXIDANT AGENTS

The spirooxindolo pyrrolidine frameworks form core units of many naturally occurring molecules possess significant pharmacological activities. The [3+2] cycloaddition reactions of azomethine ylides has been realized through multi-component reaction (MCR) affording regiospecific spiroindoline-3, 2’-pyrrolidine derivatives. The reactivity of the spiroindoline (increase EHOMO value) has been depended upon electron repelling and attracting groups. The behavior of spiroindoline towards carbon electrophile and nitrogen nucleophile can be investigated. All compound structures are fully supported by spectroscopic data and elemental analysis.The antioxidant activity for these synthesized compounds could be expected that highly antioxidant activity was with compounds which proved to possess high HOMO values

ChemInform Abstract: Ag2CO3/CA‐AA‐AmidPhos Multifunctional Catalysis in the Enantioselective 1,3‐Dipolar Cycloaddition of Azomethine Ylides.

AbstractCinchona alkaloid—amino acid derived amidophosphanes complexes (CA‐AA‐Amidphos) are shown to be efficient ligands in Ag‐catalyzed 1,3‐dipolar cycloaddition reactions of azomethine ylides with maleates.

Diastereo- and Enantioselective Copper(I)-Catalyzed Intermolecular [3+2] Cycloaddition of Azomethine Ylides with β-Trifluoromethyl β,β-Disubstituted Enones.

Reported herein is an asymmetric [3+2] cycloaddition reaction of azomethine ylides with β-trifluoromethyl β,β-disubstituted enones, a reaction which is enabled by a Ming-Phos-derived copper(I) catalyst (Ming-Phos=chiral sulfinamide monophosphines, Figure ). This method provides scalable and efficient access to the highly substituted pyrrolidines with a trifluoromethylated, all-carbon quaternary stereocenter in good yields with up to greater than 20:1 d.r. and 98 % ee. The reaction has a broad substrate scope and tolerates a wide range of functional groups.

Diastereo‐ and Enantioselective Copper(I)‐Catalyzed Intermolecular [3+2] Cycloaddition of Azomethine Ylides with β‐Trifluoromethyl β,β‐Disubstituted Enones

AbstractReported herein is an asymmetric [3+2] cycloaddition reaction of azomethine ylides with β‐trifluoromethyl β,β‐disubstituted enones, a reaction which is enabled by a Ming‐Phos‐derived copper(I) catalyst (Ming‐Phos=chiral sulfinamide monophosphines, Figure ). This method provides scalable and efficient access to the highly substituted pyrrolidines with a trifluoromethylated, all‐carbon quaternary stereocenter in good yields with up to greater than 20:1 d.r. and 98 % ee. The reaction has a broad substrate scope and tolerates a wide range of functional groups.

3 + 2] cycloaddition reaction of azomethine ylides generated by thermal ring opening of aziridines onto carbon nanohorns

Functionalization of carbon nanohorns via [3 + 2] cycloaddition of azomethine ylides generated by thermal ring opening of aziridines.

ChemInform Abstract: Regio‐ and Stereoselective Synthesis of Spiropyrrolizidines and Piperazines Through Azomethine Ylide Cycloaddition Reaction.

AbstractA new family of spirooxindolepyrrolizidines is obtained by an unprecedented isomerization of some spiroadducts obtained by one‐pot three‐component [3+2] cycloaddition reaction of pyrrolidinediones, L‐proline, and cyclic ketones.

Asymmetric synthesis approach of enantiomerically pure spiro-indenoquinoxaline pyrrolidines and spiro-indenoquinoxaline pyrrolizidines

An efficient, one-pot, four-component procedure for the synthesis of a small library of novel chiral spiro-indenoquinoxaline pyrrolidines and chiral spiro-indenoquinoxaline pyrrolizidines with high regio-, diastereo- (up to 96 dr), and enantioselectivity (up to 99% ee), through a 1,3-dipolar cycloaddition reaction of azomethine ylides and an optically active cinnamoyl–crotonoyl oxazolidinone is described. This methodology was very simple and was utilized to construct complex products from simple starting materials. The process was carried out in aqueous ethanol as an eco-friendly solvent and in the absence of any Lewis acids catalysts. The oxazolidinone chiral auxiliary was removed through a non-destructive protocol. The reaction mechanism is discussed on the basis of the assignment of the absolute configuration of the cycloadducts and using quantum mechanical calculations. The regio- and stereoselectivity were described on the basis of transition states’ stabilities and global and local reactivity indices of the reactants. The results of the theoretical calculations are in agreement with the experimental outcomes.

Synthesis of Bis-pyrrolizidine-Fused Dispiro-oxindole Analogues of Curcumin via One-Pot Azomethine Ylide Cycloaddition: Experimental and Computational Approach toward Regio- and Diastereoselection.

Curcumin has been transformed to racemic curcuminoids via an azomethine ylide cycloaddition reaction using isatin/acenaphthoquinone and proline as the reagents. The products were characterized by extensive 1D/2D NMR analysis and single-crystal X-ray crystallographic studies. The enantiomers of one racemic product were separated by HPLC on a Chiralcel OD-H column and were indeed confirmed by the CD spectra of the separated enantiomers.

Regio- and Stereoselective Synthesis of Spiropyrrolizidines and Piperazines through Azomethine Ylide Cycloaddition Reaction

A series of original spiropyrrolizidine derivatives has been prepared by a one-pot three-component [3 + 2] cycloaddition reaction of (E)-3-arylidene-1-phenyl-pyrrolidine-2,5-diones, l-proline, and the cyclic ketones 1H-indole-2,3-dione (isatin), indenoquinoxaline-11-one and acenaphthenequinone. We disclose an unprecedented isomerization of some spiroadducts leading to a new family of spirooxindolepyrrolizidines. Furthermore, these cycloadducts underwent retro-1,3-dipolar cycloaddition yielding unexpected regioisomers. Upon treatment of the dipolarophiles with in situ generated azomethine ylides from l-proline or acenaphthenequinone, formation of spiroadducts and unusual polycyclic fused piperazines through a stepwise [3 + 3] cycloaddition pathway is observed. The stereochemistry of these N-heterocycles has been confirmed by several X-ray diffraction studies. Some of these compounds exhibit extensive hydrogen bonding in the crystalline state. To enlighten the observed regio- and stereoselectivity of the [3 + 2] cycloaddition, calculations using the DFT approach at the B3LYP/6-31G(d,p) level were carried out. It was found that this reaction is under kinetic control.