Themed collection 2024 Organic Chemistry Frontiers HOT articles

This highlight presents recent advances in asymmetric synthesis that integrate electrocatalysis with biocatalysis and discusses future development directions in this field.

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 mainly focus on the assembly of chiral benzoheterocycles, such as dihydrobenzofurans, chromans, indolines, tetrahydroquinolines, etc., via Earth-abundant metal-catalyzed (Cu, Fe, Ni, and Ti) asymmetric synthesis in the last few decades.

This review summarizes the advances of gem-F₂CPs as fluoroallylic synthons in transition metal-catalysed ring-opening/cross-coupling reactions via single, double or no C-F bond cleavage on the last two years.

Recent advances focusing on novel reactivity of alkenyl boron reagents in polar or radical pathways within catalytic reactions by employing transition metal catalysis, organocatalysis have been summarized and discussed.

This review primarily focuses on the latest developments in Lewis acid-catalyzed strain-release cycloaddition reactions of BCBs.

In this review, we summarize the latest developments and applications of Mn(OAc)₃ in organic synthesis over the past decade, focusing on efforts to achieve milder reaction conditions while expanding the scope of synthesis possibilities.

This review highlights the recent progress in palladium-catalyzed C-glycosylation reactions for the synthesis of C-glycosides.

This review highlights recent advances in the atroposelective preparation of axially chiral azole derivatives, emphasizing mechanistic insights and synthetic applications in the development of this class of five-membered heterocyclic frameworks.

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.

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.

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 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.

A nickel-catalyzed 1,2-alkylarylation of alkenes has been developed, leveraging amidyl radical-triggered 1,5-HAT with electrophiles as functionalizing reagents.

Co-catalyzed asymmetric reductive addition of ketimine with cyclopropyl chloride has been realized to access diverse chiral amino esters bearing cyclopropyl fragments with broad functional group tolerance and excellent enantioselectivities.

A photoinduced FeCl₃/HCl synergistic catalytic method enables C(sp³)–S bond formation via reductive cross-coupling of activated/inert C(sp³)–H and aryl/alkyl sulfonyl chlorides through ligand-to-metal charge transfer (LMCT).

Near-infrared absorbing squaraine dyes incorporating 4-membered thionated oxocarbon and chalcogenopyrylium moieties exhibit intermediate diradical character, which impacts thermal cis–trans isomerization.

Two different mechanisms were obtained in the selective oxidation of cyclohexene catalyzed by CuCl₂ and VCl₃ respectively in presence of TBHP. The two opposed mechanisms are mainly caused by the roles of the t-BuOO˙ radical in catalytic oxidations.

Pyrroles functionalised with a thianthrenium or diphenylsulfonium group undergo Stille couplings with aryl or alkynyl stannanes in good yields, avoiding the issues of instability that can hamper the use of the analogous pyrrolyl halides.

We present a protocol for the regioselective construction of three kinds of functionalized pyrrole derivatives, i.e., PIIDOs 3–5 from HKAs with iodonium ylides promoted by AgSbF₆vs. NaSbF₆ additives in different solvents (acetone vs. DCE).

A photoredox-catalyzed radical cross–coupling protocol for the synthesis of β-amino acid derivatives has been developed. This atom-economic protocol enables the synthesis of a range of β-amino acid esters in moderate to excellent yields.

We present a metal-free photocatalytic method for the preparation of 1,4-iminoalcohols from bifunctional N-oximes, which are readily available from alcohol feedstocks.

The first manganese-catalyzed three-component coupling between secondary alcohol, allylic alcohol, and phosphine via borrowing hydrogen is described. This four-stage, one-pot reaction afforded ε-hydroxy phosphines in a step-economical fashion.

We present a cobalt-catalyzed regio-, diastereo-, and enantioselective hydroalkylation of gem-difluorocyclopropenes, accessing chiral gem-difluorocyclopropanes with vicinal stereocenters.

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.

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.

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.

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.