Reactivity and Synthetic Applications of Multicomponent Petasis Reactions

A continuous-flow protocol for photoredox-catalyzed multicomponent Petasis reaction

Here, we present a robust protocol for the facile and rapid synthesis of functionalized secondary amines in continuous flow. More specifically, we describe a detailed guide to perform a photocatalyzed Petasis reaction within 50 min using alkyl boronic acid as radical precursor and a Vapourtec E-series as key equipment. The desired functionalized amine has been synthesized in mmol scale and with a productivity rate of 0.2 mmol/h. The protocol is limited to alkyl boronic acids. For complete details on the generation and use of this protocol, please refer to Oliva et al. (2021).

Fe-Catalyzed Dicarbofunctionalization of Vinylarenes with Alkylsilyl Peroxides and β-Keto Carbonyl Substrates

The formation of two carbon-carbon bonds using vinylarenes with alkylsilyl peroxides and β-keto carbonyl substrates is effected by the presence of catalytic Fe(OTf)₂ under mild reaction conditions. A variety of vinylarenes with different substituents can be utilized in combination with several different alkylsilyl peroxides and β-keto carbonyl substrates.

Synthesis of syn- and enantioenriched anti-β-amino alcohols by highly diastereoselective borono-Mannich allylation reactions

A highly diastereoselective method for the synthesis of syn-β-amino alcohols and enantioenriched anti-β-amino alcohols has been developed involving α-hydroxyl aldehydes and chiral α-phenylaminoxyaldehydes or α-benzoyloxyaldehydes, respectively in Petasis borono-Mannich allylation reactions. This study broadens the scope and utility of the Petasis reaction to include pinacol allylboronate and highlights its unique reactivity and stereochemical outcomes.

Multicomponent Reactions (MCRs) with o-Quinone Methides

This article presents a comprehensive overview of multicomponent reactions (MCRs) that proceed via ortho-quinone methide intermediates (o-QM) generated in the reaction medium. Examples of applications involving these highly reactive intermediates in organic synthesis and biological processes (e. g., biosynthetic pathways, prodrug cleavage and electrophilic capture of biological nucleophiles) are also described. QMs are often generated by eliminative processes of phenol derivatives or by photochemical reactions, including reversible generation in photochromic substances. This class of compounds can undergo various reaction types, including nucleophilic attack at the methide carbon, with subsequent rearomatization, and react with electron-rich dienophiles in inverse-electron demand hetero-Diels-Alder reactions. Its versatile reactivity has been explored in the context of cascade reactions for the construction of several classes of substances, including complex natural products.

Iridium-Catalyzed Amidation of In Situ Prepared Silyl Ketene Acetals to Access α-Amino Esters

Disclosed herein is a convenient Ir-catalyzed amidation of esters to access α-amido esters. Initially prepared silyl ketene acetals are directly employed, without separate purification, for subsequent amidation with an oxycarbonylnitrenoid precursor using the Cp*(LX)Ir(III) catalyst. The α-amidation was facile for both α-aryl and α-alkyl esters. Density functional theory studies revealed that the generation of a putative Ir-nitrenoid is facilitated by the chelation of the countercation additive during the N-O bond cleavage of the nitrene precursor.

A Visible Light-Mediated Three-Component Strategy Based on the Ring-Opening of Cyclic Ethers with Aryldiazoacetates and Nucleophiles

A blue light-promoted reaction between aryldiazoacetates and different nucleophiles has been developed in the presence of THF (and other cyclic ethers) as solvent, allowing the incorporation of these three elements...

Acid-controlled multicomponent selective synthesis of 2,4,6-triaryl pyridines and pyrimidines by using hexamethyldisilazane as a nitrogen source under microwave irradiation

An efficient and general protocol for the synthesis of functionalized 2,4,6-triaryl pyridines and pyrimidines was developed from commercially available aromatic ketones, aldehydes and hexamethyldisilazane (HMDS) as a nitrogen source under microwave irradiation. In this multicomponent synthetic route, Lewis acids play an important role in selectively synthesizing six-membered heterocycles, including pyridines (1N) and pyrimidines (2N), by involving [2 + 1 + 2 + 1] or [2 + 1 + 1 + 1 + 1] annulated processes.

Synthesis of pyrimidines and pyridines from commercially available ketones and aldehydes by using hexamethyldisilazane as a nitrogen source and controlled by acids under microwave irradiation.

Rh(III)-Catalyzed Cascade Annulation to Produce N-acetyl Chain of Spiropyrroloisoquinoline Derivatives

A new rhodium(III)-catalyzed three-component multistep cascade spirocyclization approach was developed to synthesize nolvel N-acetyl chain of spiropyrroloisoquinoline derivatives using oxadiazoles as the directing group. This one-pot reaction also isolates aryloxadiazole...

Rh-Catalyzed Coupling of Aldehydes with Allylboronates Enables Facile Access to Ketones

We present herein a novel strategy for the preparation of ketones from aldehydes and allylic boronicesters. This reaction involves the allylation of aldehydes with allylic boronicesters and the Rh-catalyzed chain-walking of homoallylic alcohols. The key to this successful development is the protodeboronation of alkenyl borylether intermediate via a tetravalent borate anion species in the presence of KHF 2 and MeOH. This approach features mild reaction conditions, broad substrate scope, and excellent functional group tolerance. Mechanistic studies also supported that the tandem allylation and chain-walking process was involved.

Economical and Readily Accessible Preparation of o,o-Disubstituted Arylboronates through Palladium-Catalyzed Borylation of Haloarenes

Miyaura borylation, that is, palladium-catalyzed cross-coupling between bromoarenes and diboron, offers a versatile method for preparing arylboronates; however, a costly and inaccessible catalyst has been required for synthesizing highly congested arylboronates with the method. Here the Pd(OAc)₂-tri(4-methoxyphenyl)phosphine catalyst was found to work as an efficient catalyst for the sterically demanding borylation. A broad range of o,o-disubstituted bromoarenes were converted into the corresponding arylboronates in high yields by using the palladium catalyst with Cs₂CO₃ in EtOAc at 80 °C.

Green Chemistry in the Synthesis of Pharmaceuticals

The principles of green chemistry (GC) can be comprehensively implemented in green synthesis of pharmaceuticals by choosing no solvents or green solvents (preferably water), alternative reaction media, and consideration of one-pot synthesis, multicomponent reactions (MCRs), continuous processing, and process intensification approaches for atom economy and final waste reduction. The GC's execution in green synthesis can be performed using a holistic design of the active pharmaceutical ingredient's (API) life cycle, minimizing hazards and pollution, and capitalizing the resource efficiency in the synthesis technique. Thus, the presented review accounts for the comprehensive exploration of GC's principles and metrics, an appropriate implication of those ideas in each step of the reaction schemes, from raw material to an intermediate to the final product's synthesis, and the final execution of the synthesis into scalable industry-based production. For real-life examples, we have discussed the synthesis of a series of established generic pharmaceuticals, starting with the raw materials, and the intermediates of the corresponding pharmaceuticals. Researchers and industries have thoughtfully instigated a green synthesis process to control the atom economy and waste reduction to protect the environment. We have extensively discussed significant reactions relevant for green synthesis, one-pot cascade synthesis, MCRs, continuous processing, and process intensification, which may contribute to the future of green and sustainable synthesis of APIs.

Photoredox-catalyzed multicomponent Petasis reaction in batch and continuous flow with alkyl boronic acids

Multicomponent reactions (MCRs) are ideal platforms for the generation of a wide variety of organic scaffolds in a convergent and atom-economical manner. Many strategies for the generation of highly substituted and diverse structures have been developed and among these, the Petasis reaction represents a viable reaction manifold for the synthesis of substituted amines via coupling of an amine, an aldehyde and a boronic acid (BA). Despite its synthetic utility, the inherent drawbacks associated with the traditional two-electron Petasis reaction have stimulated continuous research towards more facile and tolerant methodologies. In this regard, we present the use of free alkyl BAs as effective radical precursors in this MCR through a single-electron transfer mechanism under mild reaction conditions. We have further demonstrated its applicability to photo-flow reactors, facilitating the reaction scale-up for the rapid assembly of complex molecular structures.

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Multicomponent photocatalyzed Petasis reaction

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Boronic acids as alkyl radical precursors under mild reaction conditions

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Photo-flow chemistry application for Petasis reaction

Regioselective Cross-Coupling of Isatogens with Boronic Acids to Construct 2,2-Disubstituted Indolin-3-one Derivatives

Herein we present a transition-metal-free cross-coupling reaction of isatogens with boronic acids through a 1,4-metalate shift of a boron "ate" complex. This coupling reaction provides a feasible method to deliver valuable 2,2-disubstituted indolin-3-one derivatives with excellent regioselectivity, which exhibit operational simplicity, good functional group tolerance, and a broad substrate scope.

A metal-free Petasis reaction towards the synthesis of N-(α-substituted)alkyl sulfoximines/sulfonimidamides

Herein, we disclose a metal-free novel approach for the synthesis of N-(α-substituted)alkyl sulfoximines/sulfonimidamides via one-pot multicomponent Petasis reactions of aryl boronic acids, ortho-hydroxyarylaldehydes and sulfoximines/sulfonimidamides in moderate to very good yields. The presence of two chiral centres provides a mixture of diastereomers almost in a 1 : 1 ratio, which are separated successfully in most of the cases. The -OH functionality of Petasis products is further utilized to derive heterocycles via O-allylation, followed by intramolecular Heck cyclization, proving the synthetic utility of the products.

Synthesis and Preclinical Validation of Novel Indole Derivatives as a GPR17 Agonist for Glioblastoma Treatment

The discovery of a potential ligand-targeting G protein-coupled receptor 17 (GPR17) is important for developing chemotherapeutic agents against glioblastoma multiforme (GBM). We used the integration of ligand- and structure-based cheminformatics and experimental approaches for identifying the potential GPR17 ligand for GBM treatment. Here, we identified a novel indoline-derived phenolic Mannich base as an activator of GPR17 using molecular docking of over 6000 indoline derivatives. One of the top 10 hit molecules, CHBC, with a glide score of -8.390 was synthesized through a multicomponent Petasis borono-Mannich reaction. The CHBC-GPR17 interaction leads to a rapid decrease of cAMP and Ca²⁺. CHBC exhibits the cytotoxicity effect on GBM cells in a dose-dependent manner with an IC₅₀ of 85 μM, whereas the known agonist MDL29,951 showed a negligible effect. Our findings suggest that the phenolic Mannich base could be a better GPR17 agonist than MDL29,951, and further uncovering their pharmacological properties could potentiate an inventive GBM treatment.

Regioselective Mercury(I)/Palladium(II)-Catalyzed Single-Step Approach for the Synthesis of Imines and 2-Substituted Indoles

An efficient synthesis of ketimines was achieved through a regioselective Hg(I)-catalyzed hydroamination of terminal acetylenes in the presence of anilines. The Pd(II)-catalyzed cyclization of these imines into the 2-substituted indoles was satisfactorily carried out by a C-H activation. In a single-step approach, a variety of 2-substituted indoles were also generated via a Hg(I)/Pd(II)-catalyzed, one-pot, two-step process, starting from anilines and terminal acetylenes. The arylacetylenes proved to be more effective than the alkyl derivatives.

Nickel-Catalyzed Ipso-Borylation of Silyloxyarenes via C-O Bond Activation

The conversion of silyloxyarenes to boronic acid pinacol esters via nickel catalysis is described. In contrast to other borylation protocols of inert C-O bonds, the method is competent in activating the carbon-oxygen bond of silyloxyarenes in isolated aromatic systems lacking a directing group. The catalytic functionalization of benzyl silyl ethers was also achieved under these conditions. Sequential cross-coupling reactions were achieved by leveraging the orthogonal reactivity of silyloxyarenes, which could then be functionalized subsequently.

Tetracoordinate Boron Intermediates Enable Unconventional Transformations

ConspectusOrganoboron compounds are a class of multifunctional reagents for the construction of carbon-carbon and carbon-heteroatom bonds in modern synthetic chemistry. The transformations of organoboron compounds are usually carried out through tetracoordinate boron intermediates and mainly include additions to unsaturated bonds, rearrangement reactions, transmetalation reactions, and so on. Although great progress has been achieved in improving tetracoordinate boron intermediates, there are still shortcomings, such as sparse activation modes, a paucity of reaction strategies and difficulties in stereoselective control. In this Account, we mainly discuss our recent advances in the development of unconventional transformations of organoboron compounds based on the design of tetracoordinate boron intermediates, including the following three topics: (1) the construction of C-B bonds; (2) the construction of C-C bonds; (3) the design and application of chiral tetracoordinate boron.The development of new strategies to build C-B bonds is of great interest for chemists. We have developed tandem reactions involving multiple tetracoordinate boron intermediates for the selective borylations of alkynes and the synthesis of stable tetracoordinate boron, including a domino-borylation-protodeboronation (DBP) strategy for selective borylations of alkynes, highly regio-, stereo-, and chemoselective Cu-catalyzed diborylation of β-CF₃-1,3-enynes and cascade B-Cl/C-B cross-metathesis and C-H bond borylation for the synthesis of tetracoordinate triarylboranes. We have also developed novel strategies involving tetracoordinate boron intermediates to form C-C bonds because the formation of C-C bonds is an enduring theme of organic chemistry. We disclosed long distance or multiple migration reactions and novel coupling partners in transmetalation reactions, such as long distance 1,4-migrations of tetracoordinate nitrile oxide boron and nitrilium boron intermediates, multiple migrations of tetracoordinate isocyanide boron intermediate, palladium-catalyzed Suzuki-Miyaura coupling of thioureas or thioamides, copper-catalyzed atroposelective Michael-type addition, and a palladium-catalyzed atroposelective Catellani reaction. Moreover, in terms of stereoselective control of the tetracoordinate boron intermediate, we found that a chiral tricoordinate boron complex could activate water to form a chiral tetracoordinate boron complex with Brønsted acidity, which has been successfully applied with high enantioselectivity to the asymmetric catalytic reduction of challenging indoles.This Account summarizes our recent efforts using unconventional transformations of organoboron compounds for the design of tetracoordinate boron intermediates, which not only achieved the precise construction of a wide range of diverse C-B bonds and C-C bonds but also developed a novel chiral Brønsted acid for the asymmetric catalytic reduction of challenging indoles.

Synthesis, Spectroscopic Characterization (FT-IR, NMR, UV), NPA, NBO, NLO, Thermochemical Analysis and Molecular Docking Studies of 2-((4-hydroxyphenyl)(piperidin-1-yl)methyl)phenol

In this study, a new alkylaminophenol compound was synthesized and characterized by spectroscopic techniques (FT-IR, NMR, UV). The optimized molecular geometry and the vibrational wavenumbers were calculated using density functional theory (DFT) B3LYP/WB97XD and HF methods with 6-311++ G([Formula: see text], [Formula: see text]) basis set. Thus, theoretical data were compared within themselves before comparing with experimental data. The detailed interpretation of the vibrational spectra has been carried out by VEDA program. 1H-NMR and [Formula: see text]C-NMR chemical shifts of the compound were calculated using GIAO/IEFPCM method in CDCl3. Using time-dependent (TD-DFT) approach electronic properties such as HOMO and LUMO energies, the electronic spectrum of the title compound has been studied and reported. Stability of the molecule arising from hyper conjugative interactions, charge delocalization has been analyzed using natural bond orbital (NBO) analysis. Linear polarizability, anisotropic linear polarizability and hyperpolarizability values of the title compound were found to be higher than the values of the pNA compound that are used as a standard substance in the NLO analysis. Molecular electrostatic potential (MEP), the thermodynamic properties (heat capacity, entropy and enthalpy) were calculated. Also, to investigate the biological properties of the title compound, molecular docking was done with DNA(PDB ID: 414D). It has been observed that the effective interaction is hydrogen bonds.

Multicomponent reactions as a potent tool for the synthesis of benzodiazepines

Benzodiazepines (BZDs), a diverse class of benzofused seven-membered N-heterocycles, display essential pharmacological properties and play vital roles in some biochemical processes. They have mainly been prescribed as potential therapeutic agents, which interestingly represent various biological activities such as anticancer, anxiolytic, antipsychotic, anticonvulsant, antituberculosis, muscle relaxant, and antimicrobial activities. The extensive biological activities of BZDs in various fields have encouraged medicinal chemists to discover and design novel BZD-based scaffolds as potential therapeutic candidates with the favorite biological activity through an efficient protocol. Although certainly valuable and important, conventional synthetic routes to these bicyclic benzene compounds contain methodologies often requiring multistep procedures, which suffer from waste materials generation and lack of sustainability. By contrast, multicomponent reactions (MCRs) have recently advanced as a green synthetic strategy for synthesizing BZDs with the desired scope. In this regard, MCRs, especially Ugi and Ugi-type reactions, efficiently and conveniently supply various complex synthons, which can easily be converted to the BZDs via suitable post-transformations. Also, MCRs, especially Mannich-type reactions, provide speedy and economic approaches for the one-pot and one-step synthesis of BZDs. As a result, various functionalized-BZDs have been achieved by developing mild, efficient, and high-yielding MCR protocols. This review covers all aspects of the synthesis of BZDs with a particular focus on the MCRs as well as the mechanism chemistry of synthetic protocols. The present manuscript opens a new avenue for organic, medicinal, and industrial chemists to design safe, environmentally benign, and economical methods for the synthesis of new and known BZDs.

Increased antibacterial properties of indoline-derived phenolic Mannich bases

The search for antibacterial agents for the combat of nosocomial infections is a timely problem, as antibiotic-resistant bacteria continue to thrive. The effect of indoline substituents on the antibacterial properties of aminoalkylphenols was studied, leading to the development of a library of compounds with minimum inhibitory concentrations (MICs) as low as 1.18 μM. Two novel aminoalkylphenols were identified as particularly promising, after MIC and minimum bactericidal concentrations (MBC) determination against a panel of reference strain Gram-positive bacteria, and further confirmed against 40 clinical isolates (Staphylococcus aureus, Staphylococcus epidermidis, Enterococcus faecalis, Enterococcus faecium, and Listeria monocytogenes). The same two aminoalkylphenols displayed low toxicity against two in vivo models (Artemia salina brine shrimp and Saccharomyces cerevisiae). The in vitro cytotoxicity evaluation (on human keratinocytes and human embryonic lung fibroblast cell lines) of the same compounds was also carried out. They demonstrated a particularly toxic effect on the fibroblast cell lines, with IC₅₀ in the 1.7-5.1 μM range, thus narrowing their clinical use. The desired increase in the antibacterial properties of the aminoalkylphenols, particularly indoline-derived phenolic Mannich bases, was reached by introducing an additional nitro group in the indolinyl substituent or by the replacement of a methyl by a bioisosteric trifluoromethyl substituent in the benzyl group introduced through use of boronic acids in the Petasis borono-Mannich reaction. Notably, the introduction of an additional nitro moiety did not confer added toxicity to the aminoalkylphenols.

Enantioselective Allylation of Alkenyl Boronates Promotes a 1,2-Metalate Rearrangement with 1,3-Diastereocontrol

Alkenyl boronates add to Ir(π-allyl) intermediates with high enantioselectivity. A 1,2-metalate shift forms a second C-C bond and sets a 1,3-stereochemical relationship. The three-component coupling provides tertiary boronic esters that can undergo multiple additional functionalizations. An extension to trisubstituted olefins sets three contiguous stereocenters.

Petasis vs. Strecker Amino Acid Synthesis: Convergence, Divergence and Opportunities in Organic Synthesis

α-Amino acids find widespread applications in various areas of life and physical sciences. Their syntheses are carried out by a multitude of protocols, of which Petasis and Strecker reactions have emerged as the most straightforward and most widely used. Both reactions are three-component reactions using the same starting materials, except the nucleophilic species. The differences and similarities between these two important reactions are highlighted in this review.

Asymmetric Petasis reaction for the synthesis of chiral α- and β-butadienyl amines

The Petasis reaction using (1S,2R)-1-amino-2-indanol as the substrate and an activator to construct α- and β-butadienyl amines in optically pure forms was realized, which are otherwise difficult to prepare. The reactions feature a metal-free nature, broad substrate scope, complete regioselectivities (γ-selectivity of pinacol homoallenyl- and isoprenylboronates), and high to excellent chirality induction (up to >20 : 1 dr). The favored nucleophilic addition across the Si-face of the imine intermediate was explained using DFT calculations of the six-membered chair-like transition state.

Synthesis of Ketones by C-H Functionalization of Aldehydes with Boronic Acids under Transition-Metal-Free Conditions

A method for the synthesis of ketones from aldehydes and boronic acids via a transition-metal-free C-H functionalization reaction is reported. The method employs nitrosobenzene as a reagent to drive the simultaneous activation of the boronic acid as a boronate and the activation of the C-H bond of the aldehyde as an iminium species that triggers the key C-C bond-forming step via an intramolecular migration from boron to carbon. These findings constitute a practical, scalable, and operationally straightforward method for the synthesis of ketones.

Synthetic enzyme-catalyzed multicomponent reaction for Isoxazol-5(4H)-one Syntheses, their properties and biological application; why should one study mechanisms?

In this work, we describe the application of a synthetic enzyme (synzyme) as the catalyst to promote the multicomponent synthesis of isoxazol-5(4H)-one derivatives. The catalytic system could be used up to 15 times without any notable loss of its activity. Some derivatives showed fluorescence and their photophysical data were evaluated. The mechanism of the reaction was, for the first time, investigated and, among the three reaction pathway possibilities, only one was operating under the developed conditions. ESI-MS(/MS) allowed for both the simultaneous monitoring of the multicomponent reaction (MCR) and the proposition of a kinetic model to explain the transformation. The kinetic model pointed firmly to only one reaction pathway and helped to discard the other two possibilities. The antimicrobial abilities of all synthesized derivatives against Gram-positive and Gram-negative strains were also evaluated. The abilities of functional chromophores (fluorescent compounds) as live cell-imaging probes were verified and one of the multicomponent adducts could stain early endosomes selectively in bioimaging experiments.

How and Why to Investigate Multicomponent Reactions Mechanisms? A Critical Review

We review the most innovative efforts and greatest challenges faced when elucidating multicomponent reactions (MCRs) mechanisms. When compared to traditional reactions, the often two or more concurrent reactions pathways and the greater number of possible intermediates in MCRs turn their mechanistic investigation both a harder and trickier task. The common approaches used to investigate reaction mechanisms are often unable to clarify MCRs mechanisms; hence few but clever approaches are currently used to determine these mechanisms and to depict their key transformations. Their complexity has required most innovative approaches and the use of a number of unique techniques that have shed light over the favored pathway selected from the myriad of alternatives theoretically available for MCRs. This review focuses on the most successful efforts applied by a few leading groups to perform these puzzlingly investigations.

Passerini-type reaction of boronic acids enables α-hydroxyketones synthesis

Multicomponent reactions (MCRs) facilitate the rapid and diverse construction of molecular scaffolds with modularity and step economy. In this work, engagement of boronic acids as carbon nucleophiles culminates in a Passerini-type three-component coupling reaction towards the synthesis of an expanded inventory of α-hydroxyketones with skeletal diversity. In addition to the appealing features of MCRs, this protocol portrays good functional group tolerance, broad substrate scope under mild conditions and operational simplicity. The utility of this chemistry is further demonstrated by amenable modifications of bioactive products and pharmaceuticals as well as in the functionalization of products to useful compounds.

Multicomponent reactions enable the rapid construction of diverse molecular scaffolds with modularity and step economy. In this work, the authors report the use of boronic acids as carbon nucleophiles in a Passerini-type three-component coupling reaction towards an expanded inventory of α-hydroxyketones.

Transition metal catalyzed asymmetric multicomponent reactions of unsaturated compounds using organoboron reagents

Asymmetric multicomponent reactions allow stitching several functional groups in an enantioselective and atom economical manner. The introduction of boron-based reagents as a multicomponent coupling partner has its own merits. In addition to being non-toxic and highly stable, organoboron compounds can be easily converted to other functional groups in a stereoselective manner. In the last decade several transition metal catalyzed asymmetric multicomponent strategies have been evolved using boron based reagents. This review will discuss the merits and scope of multicomponent strategies based on their difference in the reaction mechanism and transition metals involved.

Recent advances in organocatalytic asymmetric multicomponent cascade reactions for enantioselective synthesis of spirooxindoles

Catalytic asymmetric MCCRs for enantioselective synthesis of spirooxindoles by using chiral phosphoric acids, amines, bifunctional thiourea/squaramides and metal-based reagents as catalysts.

Petasis adducts of tryptanthrin – synthesis, biological activity evaluation and druglikeness assessment

The first example of a tryptanthrin-based Petasis multicomponent reaction is reported, with one of the new derivatives showing moderate fungicidal activity.

One-pot asymmetric synthesis of a hexahydrophenanthridine scaffold containing five stereocenters via an organocatalytic quadruple-cascade reaction

An organocatalytic enantioselective aza-Michael-Michael-Michael/aldol cyclization quadruple-cascade reaction of 2-amino-β-nitrostyrenes and α,β-unsaturated aldehydes has been developed for the construction of fully substituted hexahydrophenanthridine.

Recent advances in multi-component reactions and their mechanistic insights: a triennium review

This review summarizes the recent developments in MCRs, incorporating different strategies along with their mechanistic aspects.

Visible-light photocatalytic selective oxidation of C(sp3)–H bonds by anion–cation dual-metal-site nanoscale localized carbon nitride

Anion–cation dual-metal-site nanoscale localized carbon nitride exhibits a significantly enhanced photocatalytic activity for the oxidation of alkanes and alcohols with a high activity and a wide functional group tolerance.