Themed collection 2024 Organic Chemistry Frontiers HOT articles

The highlighted reports demonstrate the unique application of the direct HAT strategy to unlock new reactivity of allenes. With this novel method, a variety of structurally diverse allenes are efficiently workable.

In this highlight, recent advances in the design and synthesis of novel cycloparaphenylene (CPP)-based [2]catenanes are presented, with an emphasis on the design strategy and further investigations on their attractive properties.

This review summarises methods to synthesise and apply fluorine- and polyfluoroalkyl/aryl-substituted 1,2,3-triazoles. Focus is devoted to recent examples and those where the properties of both the 1,2,3-triazole and fluorine groups are important.

This review covers recent advances in post-functionalization of twistacenes to realize polyacenes, chiral nanographenes and their semiconductor properties, and emphasizing a promising future for constructing chiral nanotubes.

In this review, we have discussed the monofluorination of natural products or their derivatives occurring via direct C–H functionalization, late-stage functionalization and late-stage functional group transformation from 2011–2023.

Herein, we summarize recent achievements via photoinduced radical-mediated strategies that enable the precise modification of carbohydrates.

This minireview highlights recent advancements in the past five years (since 2019) in Ni/photoredox dual catalysis for Csp³–Csp³ cross-coupling reactions.

This review summarizes recent advances in the combination of Ugi-4CR and dearomatization for the synthesis of spirocycles.

This review focuses on the synthesis of C–P bonds using carbon-centered radicals with phosphorous compounds of different valence states (P^III, P^V, P₄) under photocatalysis.

This review describes recent advances in the generation of aryl radicals using light and electricity. Such modern techniques allow for efficient energy and resource utilization, thus providing more sustainable radical arylation methods.

We summarize the advancements in transition metal-catalyzed organic transformations involving vinyl radicals and provide a categorical overview based on the reaction types.

This review summarizes recent developments in nickel-catalyzed transformations of alkenes via nickelacycles, highlighting the advantages and challenges of this innovative strategy.

This review presents a comprehensive overview of the synthesis of cyclopropanes using enantioselective Michael Initiated Ring Closure (MIRC) reactions.

This review primarily focuses on the generation of aryl radicals via an electroreduction strategy, and systematically elaborates on synthetic applications, scope, and limitations of the substrates.

Nickel-catalyzed hydrofunctionalization of π-substrates is a possibly effective method to synthesize several value-added molecular architectures. This review covers the NiH catalyzed hydrofunctionalization reactions of alkenes, alkynes and allenes.

This paper primarily focuses on the editing of nitrogen atoms, encompassing the insertion of N, substitution of C with N, and utilization of ¹⁵N in place of ¹⁴N for the construction of N-heterocycles.

This review provides a comprehensive overview of metal catalysis in photo-electrochemical systems, discussing reaction mechanisms and offering prospects for this triadic catalytic mode.

This review summarizes the developments in the C–H functionalization of saturated hydrocarbons (C_nH_2n+2 and C_nH_2n) through catalytic carbene insertion into their C–H bonds dated up to February 2024, based on the categories of the types of carbenes.

Oxepanes and thiepanes are central motifs and tenants of many biologically important molecules. This comprehensive review covers synthetic methods for their preparation and use in the total synthesis of polyoxygenated oxepane natural products.

C–H bond functionalization represents one of the most efficient and straightforward strategies for diversifying existing molecules.

Mechanically interlocked molecules (MIMs) which include rotaxanes and catenanes are formed by the mechanical linking of two or more components and has the ability to switch between different states in the presence of an external stimuli.

This review summarizes the recent advances (2016–2023) in the stereoselective metal-catalyzed hydrogenation of cyclic α,β-unsaturated ketones, lactams and lactones since considerable developments were made. Where possible the application of these methodologies in synthesis is outlined.

The synthesis of small molecules and complex scaffolds is one of the most important topics in organic synthesis.

This review describes the recent advances in different reaction types and catalytic systems for the construction of C–NAr and S–NAr bonds by nitroaromatic reductive cross-coupling.

This review carefully summarizes the advances achieved in catalytic hydrofunctionalization of ynamides and is categorized by the bond formation type including C−C, C−X, C−O, C−N, C−S, C−P, C−Si, and C−Ge bonds.

Advancement in the direct C–H bond alkylation of arenes and heteroarenes using the catalysts based on the most abundant transition metal, iron, is summarized.

This review is focused on the chemistry of frustrated Lewis pairs (FLPs) with alkynes and surveys the range of stoichiometric and catalytic reactions enabled by this concept.

Organofluorine compounds are of high value. NHC-catalyzed fluorination and fluoroalkylation have served as powerful and versatile vehicles for accessing the related organofluorines. This review focuses on the recent developments in this area.

In this review, we briefly summarize the recent research progress in enantioselective higher-order cycloadditions, focusing on the preparation of medium-sized and multicyclic chiral molecules by metal-free catalysis.

This work summarizes recent progress in nickel-catalyzed propargylic substitution reactions, categorizing them based on the diverse types of nucleophiles involved, with a specific focus on exploring asymmetric transformations.

Recent advances in HAT-induced C(sp³)–H functionalizations triggered by radical addition to alkynes, including 5-exo-trig, 5-endo-trig, 4-exo-trig and 6-endo-trig cyclization cascades, and intermolecular functionalizations, are summarized.

Photoinduced radical–polar crossover cyclization (RPCC) of bifunctional alkenes is of high synthetic utility to produce cyclic products with precise alkene design. This review summarizes the recent representative advances in the field of RPC.

Nascent developments in the main group element-catalyzed hydrosilylation of alkenes and alkynes.

Diverse alkyne and dibenzylethylene derivatives were obtained via selective coupling of redox-active MCPs and ArBr under Ni/photoredox catalysis. The nickel/ligand loading tuning method played a crucial role in this divergent synthesis protocol.

A photochemical method for generating alkyl radicals and N-pyridyl radical cations from Katritzky salts and application of the radicals in functionalization of [1.1.1]propellane to generate benzophenone-type bioisosteres was reported.

Small molecules, such as trimethylamine N-oxide, interrupt intramolecular photoreactions of quinones by proton transfer and allow to convert a variety of quinones to spirocyclopropanes in a catalytic, diastereoselective, and atom-conserving manner.

Quinoidal π-extended dipyranylidene derivatives, 2,2′,6,6′-tetraphenyl-4,4′-(cyclohexa-1,4-diene-3,6-diylidene)dipyran (DP8) and its tetrakis(dimethylamino) derivative (DP9), were newly synthesized and characterized.

The development of palladium-catalysed olefin epoxidation reactions using electrophilic reagents as oxidants: modular synthesis of oxazolines. The efficient synthesis of esters, alcohols and halogen-containing products was achieved.

Z-shaped polycyclic hydrocarbons with embedded five-membered rings as well as their diaza-analogues have been synthesized and showed charge carrier mobilities up to 0.4 cm² V⁻¹ s⁻¹ in organic p-channel thin-film transistors.

DFT calculations proposed a new mechanism for the formation of the bridged ring and elucidated the solvent-controlled chemodivergence of the reaction, with the involvement of a key allyl-gold species.

The release of high-energy perfluoro-1-iodohexane molecules has been demonstrated as a major driving force for enhanced binding between calix[5]arene containers and ferrocene guests.

An aerobic double functionalization of 2,3-allenoic acids with terminal alkynes has been achieved affording versatile 4-alkynylfuran-2(5H)-one derivatives, which have been demonstrated as platform molecules for synthesis of useful natural products.

Novel catalytic four-component regiodivergent tandem carbonylative condensations of alkenes for the sustainable syntheses of acylhydrazones with high atom economy and excellent chemoselectivity have been developed.

A visible-light-induced [3 + 2] annulation of N-tosylimino(iso)quinolinium ylides with aryl olefins, catalyzed by a bisphosphonium salt has been developed. Furthermore, the synthesis method of the bisphosphonium salts was improved.

A new copper(II)-catalyzed reaction of α-carbonyl-γ-alkynyl sulfoxonium ylides with sulfonyl hydrazides in the presence of tert-butyl hydroperoxide (TBHP) is reported, regio- and stereoselectively accessing (1Z,3Z)-1,3-bismethyleneisobenzofurans.

A multicationic pillar[5]arene noncovalently crosslinks hyaluronic acid to afford ionic supramolecular polymers for intramolecular delivery of short DNA.

Herein, we report a decarbonylative C(sp²)–C(sp²) reductive cross-coupling of aroyl fluorides with aryl bromides by palladium and cobalt co-catalysis.

A doubly helical boron-doped polycyclic aromatic hydrocarbon was synthesized, which showed a low LUMO level, a high absorption coefficient and fluorescence (Φ_F = 0.73), combined with a one-dimensional π–π stacking interaction in the solid state.

Herein we present a practical approach for preparing ¹⁰B-enriched 2,1-borazaronaphthalenes from o-aminostyrenes and ¹⁰BF₃ (the primary source of boron-10) in the presence of chlorosilane.

A photocatalytic C–N cross-coupling and deaminative fluorinating strategy has been developed to afford 3-fluoro-3-hydroxyoxindoles with wide functionality tolerance and good yields.

An efficient Mn(III)-catalyzed cascade reaction of arylboronic acids, o-cyanoaryl isocyanides, and indoles was developed. The mechanism was fully investigated and elucidated.

A photoinduced copper-catalyzed alkoxycarbonylation of alkyl fluorides with phenols to synthesize various esters has been developed.

Synthesis of stable acyl intermediates and their transformation for the synthesis of carbonyl derivatives is highly desirable. We have developed a method for the synthesis of stable acyl intermediates, silyl esters, through siloxycarbonylation.

An asymmetric formal [4 + 2] cyclisation between azlactones and aza-dienes derived from simple tryptanthrins has been developed. With this established protocol, yielding a series of novel piperidine-2-one-fused tryptanthrins with up to >99 : 1 er under mild conditions.

A base-induced three-components coupling employing unactivated alkenes, fluoroalkyl iodides and diazonium salts under mild reaction conditions has been developed.

A new one-pot method for solvent-controlled switchable tandem oxidative triple functionalization of indolines has been developed via successive regioselective chalcogenation, oxidation, amination and halogenation.

Amino acid formation by hydride transfer from NADH without the need for enzymes connects prebiotic chemistry with the metabolic pathways that presumably led to these biomolecules in the first autotrophic protocells.

We present a novel synthesis of CF₃- and alkynyl-substituted quinoline derivatives based on Rh(III)-catalyzed cascade reactions of N-aryl amidines with two CF₃-ynones. Then, some products are transformed into polycyclic CF₃-benzo[k]phenanthridines through an intramolecular annulation reaction.

Reported herein is the first diaza-[1,2]-Wittig rearrangement-enabled dearomative spiroannulation reaction of indoles. This protocol features metal-free conditions, a redox-neutral process, a broad substrate scope, and a good yield.

This method allows for the enantioselective synthesis of β-azide sulfones via iron-catalyzed vicinal azide-sulfonylation of acrylamides. It makes the first instance of achieving asymmetric construction through iron catalysis with SO₂ insertion.

Branched-chain sugars and higher-carbon sugars have been efficiently prepared by site-selective C–H alkylation mediated by 1,5-HAT of ethylenoxy radicals.

Thiocarbonylation of alkenes using CO₂ was developed for the preparation of a broad array of thioesters. By the combination of Pd catalyst and N–P type carbazophosphine ligand, the reactivity and selectivity were well tuned.

A new class of chiral bipyridine-2NO ligands, which incorporate the advantages of both the bipyridine skeleton and the pyrroloimidazolone-based N-oxide moiety, was developed.

A conceptually novel single electron transfer strategy for C(sp3)–F activation-enabled [3 + 2 + 1] annulation of α-polyfluoromethyl alkenes is developed.

The synthesis of benzofulvenes from α-halo diarylethylenes through 1,4-palladium migration has been reported. The reaction accepts a variety of functional groups and affords a wide range of functionalized benzofulvenes up to 93% yields.

A catalyst-free, photoinduced three-component reaction involving sulfur dioxide insertion/sulfonyl radical addition to an unactivated CC double bond/Minisci-type cyclization sequence has been developed to access sulfonated quinazolinones.

Obscurinin A, an unprecedented Lycopodium alkaloid with an 8/6/6/6/5 ring system, showed significant inhibitory activity on the Ca_v3.1 calcium channel.