Isoindolinone Synthesis via One-Pot Type Transition Metal Catalyzed C-C Bond Forming Reactions

Direct Access to Benzolactams and Benzolactones via Nickel Catalyzed Carbonylation with CO2

A new nickel catalyzed cross-electrophile coupling for accessing γ-lactams (isoindolinones) as well as γ-lactones (isobenzofuranones) via carbonylation with CO2 is documented. The protocol exploits the synergistic role of redox-active Ni(II) complexes and AlCl3 as a CO2 activator/oxygen scavenger, leading to the formation of a wide range of cyclic amides and esters (28 examples) in good to high yields (up to 87 %). A dedicated computational investigation revealed the multiple roles played by AlCl3. In particular, the simultaneous transient protection of the pendant amino group of the starting reagents and the formation of the electrophilically activated CO2-AlCl3 adduct are shown to concur in paving the way for an energetically favorable mechanistic pathway.

Copper-catalyzed asymmetric 1,2-arylboration of enamines: access to chiral borate-containing 3,3'-disubstituted isoindolinones

An enantioselective copper-catalyzed 1,2-arylboration reaction of enamines has been developed by employing (R)-xyl-BINAP as a chiral ligand. A number of chiral borate-containing 3,3'-disubstituted isoindolinones were obtained in moderate to good yields and good to excellent enantioselectivities from the reactions of N-(o-iodobenzoyl)enamines and bis(pinacolato)diboron (B2pin2) under mild reaction conditions. Synthetic transformations of the products were conducted to demonstrate the practicality of this reaction.

Synthetic Methods for Azaheterocyclic Phosphonates and Their Biological Activity: An Update 2004-2024

The increasing importance of azaheterocyclic phosphonates in the agrochemical, synthetic, and medicinal field has provoked an intense search in the development of synthetic routes for obtaining novel members of this family of compounds. This updated review covers methodologies established since 2004, focusing on the synthesis of azaheterocyclic phosphonates, of which the phosphonate moiety is directly substituted onto to the azaheterocyclic structure. Emphasizing recent advances, this review classifies newly developed synthetic approaches according to the ring size and providing information on biological activities whenever available. Furthermore, this review summarizes information on various methods for the formation of C-P bonds, examining sustainable approaches such as the Michaelis-Arbuzov reaction, the Michaelis-Becker reaction, the Pudovik reaction, the Hirao coupling, and the Kabachnik-Fields reaction. After analyzing the biological activities and applications of azaheterocyclic phosphonates investigated in recent years, a predominant focus on the evaluation of these compounds as anticancer agents is evident. Furthermore, emerging applications underline the versatility and potential of these compounds, highlighting the need for continued research on synthetic methods to expand this interesting family.

Formation, Selective Encapsulation, and Tautomerization Control of Isoindolone Utilizing Guanidinium Sulfonate Frameworks

Herein we report the use of tetrakis (guanidinium) pyrenetetrasulfonate (G4PYR) and bis (guanidinium) 1,5-napthalene disulfonate (G2NDS) to catalyze the cyclization of 2-cyanobenzamide (1) to isoindolone (2). Moreover, we demonstrate the remarkable selectivity of these guanidinium organosulfonate hosts in encapsulating 2 over 1. By thoroughly investigating the intramolecular cyclization reaction, we determined that guanidinium and the organosulfonate moiety acts as the catalyst in this process. Additionally, 2 is selectively encapsulated, even in mixtures of other structurally similar heterocycles like indole. Furthermore, the tautomeric state of 2 (amino isoindolone (2-A) and imino isoindolinone forms (2-I)) can be controlled by utilizing different guanidinium organosulfonate frameworks.

Exploring isoindolin-1-ones as potential CDK7 inhibitors using cheminformatic tools

In women who die from cancer, breast cancer is the most common cause of death. The development of small molecular scaffolds as specific Cyclin-dependent kinase (CDK) inhibitors is a promising strategy in the discovery of anti-breast cancer drugs. Isoindolin-1-ones are heterocyclic compounds with useful therapeutic properties. In this study, a library of 48 isoindolinones has been virtually screened by molecular docking that showed high binding affinity up to - 10.1 kcal/mol and conventional hydrogen bonding interactions with active amino acid residues of CDK7. The molecular dynamics simulation (MDS), fragment molecular orbital (FMO), density functional theory (DFT), and pharmacokinetics studies of the best two docked scored ligands 7 and 14 have been studied. Examining the ligand root mean square deviation and hydrogen bonding occupancy of the 100 ns MDS trajectory, both ligands 7 and 14 showed docked pose stability. FMO calculations displayed that LYS139 and LYS41 are majorly contributing to the binding interactions with ligands 7 and 14 in the docked poses. DFT studies of ligands 7 and 14 showed high values of global softness and low values of global hardness and chemical potential thus displaying chemically reactive soft molecules and this influences their anti-cancer activity. Our hits exhibited superior qualities to known CDK7 inhibitors, according to the comprehensive pharmacokinetic parameters that were predicted. The results indicate that isoindolin-1-one moieties are good candidates for anti-cancer action and could serve as effective CDK7 inhibitors.

Supplementary Information

The online version contains supplementary material available at 10.1007/s40203-024-00225-0.

Dehydrative alkynylation of 3-hydroxyisoindolinones with terminal alkynes for the synthesis of 3-alkynylated 3,3-disubstituted isoindolinones

A brand-new procedure for the synthesis of 3-alkynylated 3,3-disubstituted isoindolinones has been disclosed via a HOTf or Fe(OTf)3-catalyzed dehydrative alkynylation of 3-hydroxyisoindolinones with terminal alkynes. Aryl, alkenyl and alkyl terminal alkynes are suitable to couple with a broad range of 3-hydroxyisoindolinones to afford the desired products in moderate to good yields. This protocol features the use of an inexpensive catalyst, mild reaction conditions, broad substrate scope and easy elaboration of the products.

Ru(II)-Catalyzed Carboamination of Olefins with α-Carbonyl Sulfoxonium Ylides

The first ruthenium-catalyzed carboamination of olefins with α-carbonyl sulfoxonium ylides is reported. The utilization of an inexpensive ruthenium catalyst enables the concise synthesis of pharmaceutically important isoindolin-1-ones, which possess both a stereogenic center and β-carbonyl side chain. This method is mild, efficient, and scalable and allows for the coupling of a wide range of aryl-, heteroaryl-, alkenyl-, and alkyl-substituted sulfoxonium ylides. Moreover, the carbonyl side chain in the resulting product provides a good handle for downstream transformations. For mechanistic studies, a ruthacyle complex is obtained and proven to be the key intermediate in both catalytic and stoichiometric reactions.

Hybrid Heterocycles: Ag(I)-Catalyzed C-C/C-N/C-O Coupled Cascade Dual Cyclization to Valuable Indolo-4H-indolones and Indolo-4H-chromenes

Herein, we report a highly efficient Ag(I)-catalyzed indolyzation with Friedel-Crafts alkylation through a cascade cyclization strategy for accessing valuable hybrid heterocycles for the first time. This general strategy consists of forming four C-C/C-N/C-O bonds toward dual annulation reactions of 2-alkynylanilines with methyl benzoate-2-carboxaldehydes and aromatic amines, as well as with salicylaldehydes and malononitrile. Variably substituted new indolo-4H-phthalimidines and indolo-4H-chromenes were synthesized with excellent yields (85-93%) under mild reaction conditions.

Carbene-Catalyzed Tandem Imine Umpolung-Intramolecular Aza-Conjugate Addition-Oxidation to Access N-Substituted Isoindolinones

Herein, we have described a novel N-heterocyclic carbene (NHC)-catalyzed synthesis of N-substituted isoindolinone acetates. The presented transformation proceeds through NHC-catalyzed tandem imine umpolung-intramolecular aza-Michael addition followed by oxidation, while molecular oxygen in air acts as a sole oxidant. Atom efficiency, operational simplicity, large-scale syntheses, and mild reaction conditions are the salient features of this method. Mechanistic studies were indicative of the necessity of molecular oxygen in air as oxidant for the conversion of imine to amide.

Synthesis of fungicidal morpholines and isochromenopyridinones via acid-catalyzed intramolecular reactions of isoindolinones

Acid-catalyzed intramolecular cyclization or rearrangement of isoindolinone derivatives is described. 3-Hydroxy/ethoxy-3,4-dihydro-6H-[1,4]-oxazino-[3,4-a]-isoindol-6-ones are obtained in moderate to good yields. Further acid-catalyzed intramolecular rearrangement reactions give 6H-isochromeno-[4,3-b]-pyridin-6-ones. The mild reaction conditions with convenient starting materials show broad substrate scope and provide the target compounds as novel pesticide leads with good fungicidal or systemical acquired resistance activities.

[Cp*IrCl2]2-Catalyzed Amidocarbonation of Olefins with Sulfoxonium Ylides toward Functionalized Isoindolin-1-ones

A [Cp*IrCl2]2-catalyzed amidocarbonation of olefins with sulfoxonium ylides has been developed to generate diverse biologically important isoindolin-1-ones in high efficiency under mild reaction conditions. Mechanism studies indicated that this cascade reaction was triggered by amino-iridation of the olefin unit to generate iridacycle, followed by formal migratory insertion with sulfoxonium ylides. This newly developed method features broad substrate scopes and operational simplicity.

Novel Oleanolic Acid-Phtalimidines Tethered 1,2,3 Triazole Hybrids as Promising Antibacterial Agents: Design, Synthesis, In Vitro Experiments and In Silico Docking Studies

As part of the valorization of agricultural waste into bioactive compounds, a series of structurally novel oleanolic acid ((3β-hydroxyolean-12-en-28-oic acid, OA-1)-phtalimidines (isoindolinones) conjugates 18a-u bearing 1,2,3-triazole moieties were designed and synthesized by treating an azide 4 previously prepared from OA-1 isolated from olive pomace (Olea europaea L.) with a wide range of propargylated phtalimidines using the Cu(I)-catalyzed click chemistry approach. OA-1 and its newly prepared analogues, 18a-u, were screened in vitro for their antibacterial activity against two Gram-positive bacteria, Staphylococcus aureus and Listeria monocytogenes, and two Gram-negative bacteria, Salmonella thyphimurium and Pseudomonas aeruginosa. Attractive results were obtained, notably against L. monocytogenes. Compounds 18d, 18g, and 18h exhibited the highest antibacterial activity when compared with OA-1 and other compounds in the series against tested pathogenic bacterial strains. A molecular docking study was performed to explore the binding mode of the most active derivatives into the active site of the ABC substrate-binding protein Lmo0181 from L. monocytogenes. Results showed the importance of both hydrogen bonding and hydrophobic interactions with the target protein and are in favor of the experimental data.

Copper-Catalyzed Sulfonylation/Cyclization of Pent-4-ynamides toward Sulfonyl-Functionalized Pyrrol-2-ones

A domino sulfonylation/intramolecular C-N coupling/dehydrogenation reaction was realized between pent-4-ynamides and sulfonyl chlorides by catalysis of Cu(acac)₂ and 2,2'-bis(diphenylphosphanyl)-1,1'-binaphthalene. The reaction provides a convenient approach to sulfonyl-functionalized pyrrol-2-ones. This method can also be applied to the synthesis of 3-alkylidene isoindolinones from 2-ethynyl-benzamides.

Palladium-Catalyzed ortho-C-H Alkoxycarbonylation of Aromatic Aldehydes via a Transient Directing Group Strategy

Transient directing groups (TDGs) can be a powerful strategy for directly functionalizing C-H bonds of aldehydes. We report a palladium-catalyzed o-C-H alkoxycarbonylation of benzaldehydes using a catalytic amount of aromatic amine to form a transient imine that plays the role of a monodentate TDG. The reaction conditions were applied to a broad range of aldehydes, and the corresponding 2-formyl benzoates were used as direct precursors for the synthesis of phthalides and 1-isoindolinones.

Synthesis of Diverse γ-Lactams via Rh-Catalyzed C(sp2)-H Addition to Aliphatic Nitriles

We herein report an unprecedented pathway to access γ-lactams using acetonitrile analogues as coupling partners without oxidants, ligands, and Lewis acids. The reaction undergoes Rh-catalyzed C(sp²)-H addition to carbon-bound nitriles with the aid of an amide traceless auxiliary followed by an annulation sequence, featuring a broad substrate scope, good functional group tolerance, and excellent chemo/stereoselectivity. Scale-up reactions and late-stage derivatizations highlight the potential synthetic utility of this methodology. A plausible mechanism is proposed based on mechanistic investigations.

Asymmetric Cascade Aza-Henry/Lactamization Reaction in the Highly Enantioselective Organocatalytic Synthesis of 3-(Nitromethyl)isoindolin-1-ones from α-Amido Sulfones

The asymmetric synthesis of novel 3-substituted isoindolinones is herein reported. A new cascade reaction was developed that consisted of the asymmetric nitro-Mannich reaction of suitable α-amido sulfones designed from 2-formyl benzoates, followed by the in situ cyclization of the adducts. Very high enantioselectivities, up to 98% ee, and very good yields were obtained in the presence of the readily available neutral bifunctional organocatalyst derived from trans-1,2-diaminocyclohexane, which is known as Takemoto’s catalyst. The investigation of the reactivity of the obtained products allowed either the selective Boc-deprotection or reduction of the nitro group, leading to further functionalized 3-substituted isoindolinones without affecting the enantiomeric purity.

Isoindolinone synthesis through Rh/Cu-catalyzed oxidative C-H/N-H annulation of N-methoxy benzamides with saturated ketones

The synthesis of isoindolinones from N-methoxy benzamides and saturated ketones via a bimetallic tandem catalytic annulation has been accomplished. The reaction is catalyzed by a Rh/Cu-cocatalytic system and proceeds via the combination of Cu-catalyzed dehydrogenation of ketones and Rh-catalyzed direct C-H functionalization with the assistance of the N-methoxy amide group which also acts as an oxidant to regenerate the Rh catalyst. This method shows good compatibility with a wide range of substrates and functional groups, and provides an alternative strategy to obtain diverse isoindolinones.

Transition metal-free advanced synthetic approaches for isoindolinones and their fused analogues

The transition metal-free synthetic protocols of isoindolinone and its fused analogues are highlighted in this review since 2007 to 2021.

Visible light-promoted aerobic oxidative cleavage and cyclization of olefins to access 3-hydroxy-isoindolinones

An environmentally friendly synthetic approach is described from 2-vinylbenzamide to 3-hydroxy-isoindolinones through visible light-promoted transformations via iron/disulfide catalysis and molecular oxygen oxidation.

Pd-Catalyzed C(sp2)-H olefination: synthesis of N-alkylated isoindolinone scaffolds from aryl amides of amino acid esters

Isoindolinone is a constituent of various natural products and synthetic biologically active compounds. The classical multi-step synthetic methods used to prepare various indolinone derivatives are tedious and challenging. One-pot synthetic methods are attractive and economical. Transition-metal-catalyzed C-H activation is an emerging tool for synthesizing natural products and small organic molecules via reducing the number of synthetic steps necessary. This paper describes the synthesis of N-alkyl-3-methenyl chiral isoindolinone derivatives from aryl amides of L-amino acids and non-activated alkene via Pd-catalyzed C(sp²)-H olefination. Herein, the amino acid residue acts as a directing group for olefination at the aryl ring, and then cyclization occurs at the amide NH. Hence, this methodology could be helpful to transform standard amino acids into respective chiral isoindolinone derivatives.

Redox-neutral rhodium(III)-catalyzed chemo- and regiospecific [4 + 1] annulation between benzamides and alkenes for the synthesis of functionalized isoindolinones

Herein, using electron-deficient alkenes embedded with an oxidizing function/leaving group as a rare and nontraditional C₁ synthon, we have achieved the redox-neutral Rh(III)-catalyzed chemo- and regioselective [4 + 1] annulation of benzamides for the synthesis of functionalized isoindolinones. This method features broad substrate scope, good to excellent yields, excellent chemo- and regioselectivity, good tolerance of functional groups and mild external-oxidant-free conditions.

Base-Promoted Cascade Reactions for the Synthesis of 3,3-Dialkylated Isoindolin-1-ones and 3-Methyleneisoindolin-1-ones

Cascade reactions of ortho-carbonyl-substituted benzonitriles with ((chloromethyl)sulfonyl)benzenes as pronucleophiles led to new isoindolin-1-ones with a tetrasubstituted C-3 position or to (Z)-3-(sulfonyl-methylene)isoindolin-1-ones. The reactions start from readily available materials, are carried out under mild conditions, and do not require metal catalysis. Promoted only by the cheap and environmentally benign K₂CO₃ as the base, up to six elemental steps can be combined in a single pot. Hence, a sequential one-pot cascade/β-elimination/alkylation furnished useful intermediates for the synthesis of aristolactam natural products. The observed selectivity and the mechanism were investigated by DFT studies.

The First Highly Enantioselective Synthesis of 3-Sulfinyl-Substituted Isoindolinones Having Adjacent Carbon and Sulfur Stereocenters

A highly stereoselective access to 3-sulfinyl-substituted isoindolinones has been achieved by a tandem organocatalytic addition/cyclization reaction of 2-carbobenzyloxy-N-tosylbenzylidenimine with thiols and succeeding diastereoselective oxidation with MCPBA. First, enantioenriched isoindolinone N,S-acetals have been obtained through a dynamic kinetic asymmetric transformation induced by a bifunctional chiral thiourea organocatalyst. In turn, the newly created carbon stereocenter enabled a high diastereocontrol in the subsequent sulfoxidation. Based on DFT calculations, a theoretical rationale for the stereoselectivity of the oxidation reaction is also provided.

Diastereoselective synthesis of chiral 3-substituted isoindolinones via rhodium(III)-catalyzed oxidative C-H olefination/annulation

A new method for the direct and stereoselective synthesis of 3-substituted isoindolinones via Rh(iii)-catalyzed chiral N-sulfinyl amide directed asymmetric [4 + 1] annulation of benzamides with acrylic esters has been developed. The reaction proceeded through an oxidative C-H olefination and a subsequent cyclization by intramolecular aza-Michael addition, producing a series of diastereoisomeric chiral isoindolinones (20 examples) in generally good yields with a dr value up to 5.5 : 1. The absolute configurations of the newly formed C-stereocenters in the major and minor diastereomers of the catalysis product have been determined by X-ray crystal diffraction analysis to be S and R, respectively. The separation of the major diastereoisomers from the catalysis products and subsequent removal of the N-sulfinyl chiral auxiliary afforded enantiomerically pure (S)-isoindolinones. The application of the obtained (S)-isoindolinones in the synthesis of several biologically active isoindolinones such as (S)-PD172938, (S)-pazinaclone and (S)-pagoclone is presented.

Isoindolinone Synthesis via One-Pot Type Transition Metal Catalyzed C-C Bond Forming Reactions

Isoindolinone structure is an important privileged scaffold found in a large variety of naturally occurring as well as synthetic, biologically and pharmaceutically active compounds. Owing to its crucial role in a number of applications, the synthetic methodologies for accessing this heterocyclic skeleton have received significant attention during the past decade. In general, the synthetic strategies can be divided into two categories: First, direct utilization of phthalimides or phthalimidines as starting materials for the synthesis of isoindolinones; and second, construction of the lactam and/or aromatic rings by different catalytic methods, including C-H activation, cross-coupling, carbonylation, condensation, addition and formal cycloaddition reactions. Especially in the last mentioned, utilization of transition metal catalysts provides access to a broad range of substituted isoindolinones. Herein, the recent advances (2010-2020) in transition metal catalyzed synthetic methodologies via formation of new C-C bonds for isoindolinones are reviewed.

Asymmetric synthesis of 3-benzyl and allyl isoindolinones by Pd-catalyzed dicarbofunctionalization of 1,1-disubstituted enamides

The Pd-catalyzed enantioselective Heck/Suzuki reaction of 1,1-disubstituted enamides with aryl/vinyl boronic acids has been developed to access 3-benzyl/allyl substituted isoindolinones bearing a tetrasubstituted stereogenic carbon center.

Palladium-catalyzed dehydrogenative C–H cyclization for isoindolinone synthesis

In this paper Pd-catalyzed intramolecular dehydrogenative C(sp³)–H amidation for the synthesis of isoindolinones is described. This method features the use of a Pd/C catalyst and the addition of a stoichiometric amount of oxidant is not necessary. A mechanistic study suggested the possible formation of H₂ gas during the reaction.

Pd-catalyzed intramolecular dehydrogenative C(sp³)–H amidation for the synthesis of isoindolinones was developed. Use of Pd/C as a catalyst enables the desired cyclization to proceed smoothly without adding any stoichiometric oxidants.