One-Pot Regioselective Synthesis of meta-Terphenyls via [3 + 3] Annulation of Nitroallylic Acetates with Alkylidenemalononitriles

Metal free synthesis of thermally stable blue fluorescent m-terphenyls by ring transformation of 2H-pyran-2-ones: chemical synthesis, spectroscopy and computational studies

A simple yet convenient nucleophile-induced synthetic route for the construction of thermally stable fluorescent active functionalized stilbenes has been delineated. The nucleophile-induced base encouraged synthetic protocol was performed under mild conditions without harming the environment and products were achieved in good yields. The synthesized stilbenes showed amazing emission properties and good thermal stability. Synthesized products displayed interesting positive solvatochromism in different solvents based on variation in polarity. Further, we present a comprehensive analysis of the eight molecules, leveraging a combination of Density Functional Tight Binding (DFTB), Density Functional Theory (DFT) calculations, and Molecular Dynamics (MD) simulations. This integrated approach allowed for an in-depth exploration of the electronic structures, reactivity profiles, and dynamic behaviors of these complex molecular systems. Our findings reveal significant insights into the physicochemical properties of the synthesized molecules, contributing to a deeper understanding of their potential applications in various fields.

Stereocontrolled Construction of Spirooxindole-Containing 5,6,7,8-Tetrahydropyrrolo[1,2-a]pyridine via Michael/Friedel-Crafts Domino Reaction Promoted by Secondary Amine-Squaramide

An asymmetric Michael/Friedel-Crafts cascade reaction with Morita-Baylis-Hillman (MBH) nitroallylic esters and 3-pyrrolyloxindoles has been developed for the stereoselective construction of spirooxindole-containing tetrahydroindolizines. A range of tetracyclic scaffolds possessing three consecutive chiral centers, including an all-carbon quaternary stereocenter, were generated in 53-85% isolated yields with high diastereoselectivities and enantiopurities (≥3:1 dr, 50-98% ee). A newly synthesized bifunctional secondary amine/squaramide organocatalyst was demonstrated to exhibit better stereochemical control than their tertiary analogues.

Synthesis of tetrahydrochromenes and dihydronaphthofurans via a cascade process of [3 + 3] and [3 + 2] annulation reactions: mechanistic insight for 6-endo-trig and 5-exo-trig cyclisation

Substituted tetrahydrochromenes and dihydronaphthofurans are easily accessible by the treatment of β-tetralone with trans-β-nitro styrene derived Morita-Baylis-Hillman (MBH) acetates through a formal [3 + 3]/[3 + 2] annulation. The reaction proceeds through a cascade Michael/oxa-Michael pathway with moderate to good yields. A DFT study was carried out to account for the formation of the corresponding six and five-membered heterocycles via 6-endo-trig and 5-exo-trig cyclization.

Synthesis of fully functionalised spiropyran pyrazolone skeletons via a formal [4 + 2] cascade process using β-nitro-styrene-derived MBH-alcohols

An efficient protocol was established to construct spiro pyrazolone tetrahydropyran scaffolds at ambient temperature under metal-free conditions. The reaction proceeded via formal [4 + 2] cyclisation of trans-β-nitro-styrene-derived Morita-Baylis-Hillman (MBH) alcohol with α-arylidene pyrazolone. The reaction followed an oxa-Michael/Michael cascade pathway, resulting in the formation of new C-C and C-O bonds. Organocatalytic synthesis of spiropyrazolones using quinine-derived catalyst resulted in 94% enantiomeric excess (ee) and excellent (>20 : 1) diastereoselectivity.

Design, synthesis, and biological evaluation of tetrahydro-αcarbolines as Akt1 inhibitors that inhibit colorectal cancer cells proliferation

A series of densely functionalized THαCs were designed and synthesized as Akt1 inhibitors. Organocatalytic [3+3] annulation between indolin-2-imines 1 and nitroallylic acetates 2 provided rapid access to this pharmacologically interesting framework. In vitro kinase inhibitory abilities and cytotoxicity assays revealed that compound 3af was the most potent Akt1 inhibitor, and mechanistic study indicated that compound 3af suppressed the proliferation of colorectal cancer cells via inducing apoptosis and autophagy. Molecular docking suggested that the indole fragment of 3af was inserted into the hydrophobic pocket of Akt1 protein, and the H-bond between 3af and residue Lys179 also contributed to the stable binding. This article provides an efficient strategy to design and synthesize biologically important compounds as novel Akt1 inhibitors.

Recent advances in the synthesis of cyclic compounds using α,α-dicyanoolefins as versatile vinylogous nucleophiles

This article provides a review of the applications of α,α-dicyanoolefins as versatile vinylogous nucleophiles in the synthesis of various cyclic compounds, covering the literature from the past 13 years.

Benzannulation Reactions: A Case for Perspective Change From Arene Decoration to Arene Construction

Benzannulation reactions involve construction of a benzene ring from acyclic precursors. This class of reactions offer a versatile and often superior alternative to aromatic substitution for construction of substituted arenes. Selected pioneering and recent reports of various benzannulation reactions are categorised and discussed in this review.

Metal-Free and Regioselective Synthesis of Functionalized α-Carbolines via [3 + 3] Annulation of Morita-Baylis-Hillman Acetates of Nitroalkenes with Iminoindolines

A facile, metal-free method for the synthesis of substituted α-carbolines from secondary Morita-Baylis-Hillman (MBH) acetates of nitroalkenes is presented. The cascade reaction of MBH acetates with tosyliminoindolines occurs regioselectively to form various α-carbolines with a wide substrate scope. The reaction involves mild conditions, and the products are formed in high yields within a short reaction time. The amenability of the reaction to scale up and synthetic applications of the products have been demonstrated.

Regioselective synthesis of benzonitriles via amino-catalyzed [3+3] benzannulation reaction

A straightforward synthesis of benzonitriles is achieved via amino-catalyzed [3+3] benzannulation of α,β-unsaturated aldehydes and 4-arylsulfonyl-2-butenenitriles. Using pyrrolidine as an organocatalyst via iminium activation, a series of substituted benzonitriles were obtained in good to high yields in a regioselective manner. This reaction can proceed smoothly under mild reaction conditions and without the aid of any metals, additional oxidants, or strong bases, thus making this an efficient and environmentally friendly method to access benzonitriles.

Synthesis of tetrahydrothiopyrano[2,3-b]indoles via [3+3] annulation of nitroallylic acetates with indoline-2-thiones

[3+3] annulation of 1,3-binucleophilic indolin-2-thione with 1,3-bielectrophilic nitroallylic acetate via an S_N2-reaction-6-endo-trig cyclization takes place with high regio- and stereoselectivity to afford tetrahydrothiopyranoindoles.

Substrate-directed chemo- and regioselective synthesis of polyfunctionalized trifluoromethylarenes via organocatalytic benzannulation

Highly chemo- and regioselective substrate-directed benzannulation of trisubstituted CF₃-alkenes and 2-benzylidenemalononitriles or 2-nitroallylic acetates has been achieved via Michael-initiated [4 + 2] or Rauhut–Currier-initiated [3 + 3] annulation.

Direct access to multi-functionalized benzenes via [4 + 2] annulation of α-cyano-β-methylenones and α,β-unsaturated aldehydes

An efficient [4 + 2] benzannulation of α-cyano-β-methylenones and α,β-unsaturated aldehydes was achieved under metal-free reaction conditions selectively delivering a wide range of polyfunctional benzenes in high yields respectively (up to 94% yield).

An efficient [4 + 2] benzannulation of α-cyano-β-methylenones and α,β-unsaturated aldehydes was achieved under metal-free reaction conditions selectively delivering a wide range of polyfunctional benzenes in high yields respectively (up to 94% yield).

Facile synthesis of biarylmethanes and tetrasubstituted arenes via a base-mediated [3 + 3] benzannulation reaction of Morita–Baylis–Hillman adducts and unsaturated sulfones

A regioselective DBU-mediated [3 + 3] benzannulation reaction of 1,3-bis-sulfonyl propenes and Morita–Baylis–Hillman (MBH) bromides to afford bis-sulfonyl biarylmethanes/arenes is described.

Facile synthesis of substituted diaryl sulfones via a [3 + 3] benzannulation strategy

A metal-free and efficient synthesis of highly substituted diaryl sulfones via a base-mediated [3 + 3] benzannulation strategy.

An efficient synthesis of 4,5-disubstituted-2H-1,2,3-triazoles from nitroallylic derivatives via a cycloaddition–denitration process

A variety of nitroallylic derivatives were smoothly reacted with sodium azide in the presence of p-TsOH to form synthetically-viable triazoles.

R, Sajith AM, K. V. D, C. S, Anwar S. Functionalised dihydroazo pyrimidine derivatives from Morita–Baylis–Hillman acetates: synthesis and studies against acetylcholinesterase as its inhibitors

Dihydroazo pyrimidine derivatives were synthesized at room temperature using MBH acetates and aminoazole derivatives. The in vitro studies carried on a couple of derivatives exhibited much higher potency for Alzheimer's disease (AD).

Base-mediated synthesis of highly functionalized 2-aminonicotinonitriles from α-keto vinyl azides and α,α-dicyanoalkenes

A novel access to highly functionalized 2-aminonicotinonitriles via efficient annulations of α-keto vinyl azides and α,α-dicyanoalkenes is described.

Synthesis of hydrazinoheterocycles from Morita–Baylis–Hillman adducts of nitroalkenes with azodicarboxylates

Hydrazinonitroalkenes derived from nitroalkenes and azodicarboxylates are excellent substrates for the synthesis of hitherto unreported hydrazinotriazoles and hydrazinodihydrofurans.

Imidazoles from nitroallylic acetates and α-bromonitroalkenes with amidines: synthesis and trypanocidal activity studies

One-pot cascade reactions of amidines with nitroallylic acetates and α-bromonitroalkenes provide functionalized imidazoles that exhibit trypanocidal activity.

One-pot regioselective synthesis of functionalized and fused furans from Morita–Baylis–Hillman and Rauhut–Currier adducts of nitroalkenes

Functionalized and fused furans were synthesized by a one-pot regioselective cascade reaction from Morita–Baylis–Hillman acetates and Rauhut–Currier adducts of nitroalkenes.

Synthesis of imidazoles via cascade reaction of nitroallylic acetates with amidines and studies on their trypanocidal activity

Functionalized imidazoles derived from nitroallylic acetates and amidines exhibit potent activity against T. cruzi, the etiological agent of Chagas disease.

Synthesis of highly diversified 1,2,3-triazole derivatives via domino [3 + 2] azide cycloaddition and denitration reaction sequence

Synthesis of 1,2,3-triazoles via domino azide cycloaddition and denitration reaction sequence under catalyst free conditions is described. Sodium azide treatment of Baylis–Hillman adducts and their cyclic derivatives from nitro olefins gave the triazoles in excellent yield.