Themed collection 2023 Organic Chemistry Frontiers HOT articles

The synthetic and mechanistic aspects of the role of the trisulfide radical anion S₃˙⁻ in organic chemistry are reviewed.

This review highlights the recent advances in both electrochemical borylation and hydroboration to synthesize organoboron compounds and electrochemical transformation of organoboron compounds to construct carbon–carbon and carbon–heteroatom bonds.

Recent advances in the electrochemical generation of 1,3-dicarbonyl radicals from C–H bonds and their mechanistic insights and synthetic applications have been summarized.

This review summarizes the recent advances in cyclization reactions involving pyridinium 1,n-zwitterions (n = 4 and 5) and highlights the applications of pyridinium 1,n-zwitterions (n = 4 and 5) in the efficient construction of heterocycles.

This review summarizes a view of the advances in the catalytic asymmetric α-functionalization of vinylogous nucleophilic species, the content of which is categorized based on the type of vinylogous donor.

This review focuses on the very recent advances (from 2020 to the beginning of 2023) in enantioselective catalytic reactions for the construction of oxa-quaternary stereocenters.

Artemeriopolides A–D (1–4), four novel cadinane sesquiterpenoid dimers featuring the rare 2-oxaspiro[4.6]undecan-1,7-dione, 2-oxaspiro[4.5]decan-1-one, and 2-oxaspiro[5.5]undecan-1-one ring systems, were isolated from Artemisia eriopoda.

CAT catalyzes the reaction of 1a to generate intermediate INT2, which is a common intermediate to generate final products 2a and 3a.

A novel and highly efficient strategy for the construction of diverse alkenyl sulfoxides via transition metal-free C–S cross-coupling of sulfenate anions with alkenylsulfonium salts is reported.

This report describes the visible-light-induced C–H/COO–H oxidative coupling reaction of 2-arylbenzoic acids to synthesize benzo-3,4-coumarins by using 2,7-dinitrophenanthrene-9,10-dione as a photocatalyst.

The first asymmetric [4 + 1] annulation of oxindole 3-pyridinium salts and hydrazones is realized by using a chiral N,N′-dioxide-Pr(OTf)₃ complex. A range of bioactive chiral pyrazoline-spirooxindoles are obtained in good yields with excellent ee values.

An electrophilic sulfenylation promoted oxidation of alkynes is presented, providing the chemo-, regio- and stereoselective synthesis of α-sulfenylated α,β-unsaturated aldehydes.

A photoredox catalysed 1,3-oxylallylation of aryl cyclopropanes was accomplished by reaction with carboxylic acids and allyl sulfones.

COAP-Pd-catalyzed asymmetric cascade formal [4 + 1] annulation was developed between racemic vinyl benzoxazinones and N-tosylhydrazone sodium salts, affording trans-2,3-disubstituted indolines in good yields with high stereoselectivity.

Carboxylic acid-assisted sterically demanding reductive cross-coupling between cycloalkenyl and alkyl bromides affords all-carbon tetrasubstituted cycloalkenes under mild reaction conditions in good yields.

A new multicomponent copper(I)-catalyzed interrupted click reaction which allows the rapid modular synthesis of multisubstituted triazole sulfides including various medium-sized and macrocycles in one-step from elemental sulfur was reported.

A photocatalytic dehydration method was developed to efficiently convert benzyl alcohols to the corresponding amides.

Despite significant development of the nascent anion–π interactions in recent years, the noncovalent interactions between fluoride ion, a unique anion species, and electron-neutral aromatic rings remain rare and even controversial.

The bis(pentafluorophenyl)borane-catalyzed E-selective isomerization of terminal alkenes to internal alkenes via a hydroboration/retro-hydroboration sequence is reported.

By combining HTE and machine learning technologies, an iridium(I)-catalyzed highly selective O–H bond insertion reaction of carboxylic acids and sulfoxonium ylides was developed, and an extensive reaction space exploration was accomplished.

An efficient tandem Dowd–Beckwith ring expansion/C–H functionalization of tetrahydroisoquinoline (THIQ) is disclosed upon photocatalysis, which provided a unique thought to connect important medium-sized cycloalkanones with THIQs skeletons together.

The transition metal catalyzed cycloaddition reaction is one of the most powerful tools for the construction of carbon- and heterocycles. DFT studies are performed to investigate the mechanism of the Ni-catalyzed intramolecular [4 + 2] cycloaddition.

Visible light-mediated NHC and photoredox co-catalyzed radical 1,2-sulfonylacylation of allenes via cross-coupling between an allyl radical and an NHC-stabilized acyl radical.

Synthesis of β-azido alkylsulfones through a photoredox-catalyzed azido sulfonylation of alkenes with DABCO·(SO₂)₂, trimethylsilyl azide and alkyl thianthrenium salts is developed.

A photo-induced redox cascade reaction has been developed for the chemoselective construction of isoxazolidine derivatives from stable and easily available nitroarenes and amines.

Photo-induced C–H functionalization for divergent synthesis of quinoxalin-2(1H)-one derivatives using H₂O₂ as an oxidant without a photocatalyst.

The in situ generated aminodiborane  (μ-NH₂B₂H₅) using NH₃BH₃ and elemental iodine (I₂) is used for the reduction of carboxamides to amines.

Direct C–H amination methods are essential because of the importance of aryl amine derivatives.

We describe the Cr-catalyzed enantioconvergent synthesis of chiral 2,3-allenones from aldehydes and propargyl bromides, which features an unprecedented cascade of Cr-catalyzed asymmetric reductive radical–polar crossover and Oppenauer oxidation.

The size of supramolecular vesicles is manipulated by regulating the assembly of macrocycles with different mono- or bi-pyridinium salts.

Telluropyran derivatives have been facilely synthesized via a ring-expansion cyclization from the corresponding tellurophene compounds and their conjugation can be extended via various transition metal-catalyzed coupling reactions.

Organocatalytic enantioselective construction of chiral spiro N,N-acetal carbon stereocenters and axially chiral 3-arylindoles has been achieved in one pot.

A novel and practical strategy for the dehalocarboxylation of C(sp²)-halides with formate via visible-light photoredox nickel dual catalysis was disclosed.

A ruthenium-catalyzed C–H amidation using cyclic amides as directing groups features broad functional group tolerance. Mechanistic studies supported by DFT calculations highlight the relevance of six-membered ruthenacycles in the catalytic cycle.

A bidirectional Pictet-Spengler Reaction allows easy access to nitrogen-rich aromatics with seven fused rings. Photophysical measurements and computational methods show significant differences to parent N-heteropolycycles with fewer nitrogen atoms.