A copper-catalyzed protocol furnishing N-arylated sulfoximines has been developed via dual N–H/C–H activation. Arylalkyl- and less reactive diarylsulfoximines were efficiently coupled with privileged scaffolds like indolines, indoles, and N-Ar-7-azaindoles. Sulfoximines based on medicinally relevant scaffolds (phenothiazine, dibenzothiophene, thioxanthenone) were also well tolerated. Detailed mechanistic studies indicate that the deprotometalation and protodemetalation step is the reversible step.

A combination of CsF and hexamethyldisilane in DMSO enabling an anti-Markovnikov formal hydrotrimethylsilylation of styrenes is reported. Mechanistic investigations detail the reaction pathways, including in situ generation of a silyl anion, the addition of this silyl anion onto the alkene to form a carbanion, and this carbanion is then protonated by DMSO. The choice of the solvent to match its reactivity with the carbanion and silyl anion is key to the success of this reaction.

A novel synthetic strategy for efficient construction of dragon-boat-type heptathienoacenes (DBHTs) via the α–β position carbon–carbon cross-coupling between two dithienothiophenes is employed. Their crystal structures are confirmed by X-ray single-crystal analysis. The first thin film FET devices of heptathienoacenes are fabricated using OTS-treated SiO₂/Si substrates, in which DBHT-5-based devices exhibit an unprecedented highest hole mobility value of 1.15 cm² V^–1 s^–1 and on/off ratios over 10⁶ with a threshold voltage of 0 V.

A carboxylate-assisted iridium(III)-catalyzed regioselective C(sp²)–H heteroarylation/esterification reaction of acrylic acid is disclosed herein for the first time. This catalytic protocol tolerates various α-substituted, β-substituted, and α, β-disubstituted acrylic acids as well as heteroaromatic boronates well. The resulting 3,4-dihydro-2H-pyran-6-carboxylic acid derivative 3r highlighted the AIE-active luminophore with multiple emission signal properties and a high quantum yield of 28%, exhibiting the potential application of this methodology for the synthesis of nitrogen-containing organic functional materials.

The unprecedented photochemical late-stage defluorinative gem-difluoroallylation of aryl sulfonium salts, which are formed site-selectively by direct C(sp²)─H functionalization, is herein disclosed. This method is distinguished by its mild reaction conditions, wide scope, and excellent site-selectivity. As showcase examples, a Flurbiprofen and Pyriproxyfen derivatives could be late stage C(sp²)─H gem-difluoroallylated with high yields. Experimental and computational investigations were conducted.

A streamlined second generation of redox-responsive phenazine-based butterfly coil foldamers has been developed using a novel Z-shaped linker. Their ability to undergo fully reversible extension-contraction has been demonstrated using catalytic hydrogenation and bulk electrolysis.

Herein, we report the direct selective C–H lactonization of fatty acids (C5–C16), catalyzed by manganese(II) complexes bearing bis-amino-bis-pyridine ligands. The catalyst system uses the environmentally benign hydrogen peroxide as oxidant and exhibits high efficiency (100–200 TON), providing under optimized conditions γ-lactones in 60–90% yields. Remarkably, by changing the reaction conditions, the oxidation of hexanoic acid can be diverted toward formation of δ-caprolactone in up to 67% yield. Furthermore, the possibility of obtaining (ω-1)-hydroxy derivatives from linear C7–C10 acids in up to 48% yields has been demonstrated.

A TMSOTf-mediated highly diastereoselective synthesis of isoxazolidine bearing three contiguous stereocenters is described. This method utilizes O-propargyl hydroxylamines as a novel building block for the rapid assembly of the isoxazolidines via alkyne–oximium cyclization. The strategy could be used in the synthesis of enantiomerically enriched isoxazolidines. Reductive cleavage of the N–O bond efficiently gives the corresponding 1,3-aminodiols with precise control over all stereocenters formed.

While Sharpless asymmetric dihydroxylation is widely utilized to convert various alkenes into diols with excellent enantioselectivies, kinetic resolution by means of this fundamental catalysis has generally proven to be ineffective. Here we report that, by relying on noncovalent π-interactions that purposely include the substrate’s stereocenter in the corresponding catalyst–substrate interaction framework, AD-based kinetic resolution of allylic amides is realized. This method enables such versatile chiral building blocks to be easily accessed with excellent enantiomeric excesses (ee’s).

The highly stereoselective construction of C₂-symmetric cis,cis- and trans,trans-2,6-dioxabicyclo[3.3.0]octane (fused bis-tetrahydrofuran) skeletons 4a and 4b has been accomplished via a novel stereodivergent double intramolecular amide enolate alkylation of common cyclization substrate 5 through the judicious choice of “chelate” versus crown ether-promoted “nonchelate” control. Application of this methodology has provided access to substrate-controlled concise total syntheses of (+)-laurenidificin (3) and (+)-aplysiallene (ent-2), which possess cis/cis- and trans/trans-fused bis-tetrahydrofuran cores, respectively.

High value oxygenated polycycles have been rapidly and efficiently accessed from simple precursors in one pot processes. The reported methodology relies on a new and mild method for butenolide synthesis mediated by thiols. The initial photooxygenation and butenolide synthesis have been merged with subsequent photoredox reactions to achieve rare dual-photocatalyst cascades affording various fused butyrolactones. Ground state Lewis acid activity for methylene blue has been unveiled and then exploited in the synthesis of substituted cyclopentanones.

A chiral phosphoric acid-catalyzed ring-opening of meso-epoxides was developed. A range of 2-azabicyclo[2.2.1]heptanes were obtained in high yields with excellent enantioselectivities. In addition, the hydroxyl and amide groups in the products provided handles for further derivatization.

Herein, we disclose substrate-dependent rearrangements of 4-substituted N-sulfonyl-1,2,3-triazoles under Rh(II)-catalysis via denitrogenation. The reaction pathways included key 1,2-aryl migration via the formation of intermediatory phenonium ion, which is elusive so far with Rh-azavinyl carbenes. Intriguingly, the transformations were completely dependent on the substituent present leading to different scaffolds like enaminones, pyrrol-3-ones, and azadienes. Hammett studies provided essential insights into the carbocationic intermediate formation. The developed methodology featured simple reaction conditions, excellent functional group compatibility, and broad substrate scope.

Sulfur(VI) fluoride motifs are important entities in organic chemistry. Typically, their syntheses involve the corresponding chlorides, which are often difficult to prepare and characterized by a poor storability due to the inherently weak S–Cl bond. Here, a single-step procedure for the preparation of sulfur(VI) fluorides starting from sulfonyl imidazoles as stable S(VI) reservoirs is described. By using a simple combination of AcOH and potassium bifluoride (KF₂H), an imidazole-to-fluorine exchange furnishes a variety of sulfonyl, sulfonimidoyl, sulfoxyl, and sulfamoyl fluorides in good to excellent yields.

Direct evidence explaining why 2-propynamides have never been used as substrates in Tf₂O-promoted electrophilic activations was obtained. Furthermore, a new method for the synthesis of structurally special 2,4-disubstituted quinolines was developed, by which the substituent at position 2 of quinolines can be diversified easily.

o-Arene-connected porphyrinoids were synthesized with o-(2-thienyl)vinylarene motif as a new building block for porphyrinoids. This motif can replace meso-aryl-substituted dipyrromethene and serve as a command key arranging o-connectivity of porphyrinoid. While 6a (benzene version) is very weak, 6b (pyridine version) shows a substantial amount of diatropic ring current due to reduced steric hindrance (without H23) and rigidified Pd-6a became more aromatic than 6b.

A rhodium-catalyzed highly enantio- and diastereoselective alkenylation of β,γ-unsaturated butenolides is reported. The use of a chiral diene ligand, (S,S)-Ph-bod, enables the facile synthesis of chiral butyrolactones in high yields with extremely high enantioselectivities (>99% ee in all cases) and high diastereoselectivities (up to >20:1 dr). The key process of the reaction involves the isomerization of β,γ-unsaturated butenolides to racemic α,β-unsaturated butenolides and the subsequent dynamic kinetic resolution through ligand-controlled, enantioselective alkenylation with an alkenylrhodium species that is generated in situ via 1,4-rhodium migration.

Bicyclo[2.1.1]hexanes have become increasingly popular building blocks in medicinal chemistry as bridged scaffolds that provide unexplored chemical space. We herein report a visible light-driven approach to these compounds that relies on an intramolecular crossed [2 + 2] photocycloaddition of styrene derivatives enabled by triplet energy transfer. Bicyclo[2.1.1]hexanes were obtained in good to high yields (19 examples, 61%-quantitative yield) and allowed for further functionalizations by consecutive reactions, thereby opening different pathways to decorate the aliphatic core structure.

Although solutions of hydrogen chloride in ethereal solvents like diethyl ether or dioxane are commonly employed in the laboratory, the solution structure of these reagents has yet to be firmly established. Here, we analyze solutions of ethereal hydrogen chloride or deuterium chloride in toluene, in dichloromethane, or in the absence of a co-solvent by in situ infrared spectroscopy. The resulting spectra are inconsistent with free HCl or often-proposed 1:1 HCl–ether complexes but closely match the predicted spectra of oxonium ions generated via protonation of diethyl ether. Molecular dynamics simulation of the oxonium chloride complexes provides evidence for an outer-sphere contact ion pair. These results suggest new approaches for tuning the acidity of strong Brønsted acids in organic solvents and demonstrate the importance of conducting spectroscopic measurements under reaction-relevant conditions.

By integrating two approaches─an ethene bridge to enhance safety and planarity to support good density─we have achieved new high-energy-density materials 4–8. Compounds 4–8 show good detonation performance (D_v = 8037–9305 m s^–1 and D_P = 24.7–33.4 GPa) and large enthalpies of formation (260.1–1444.9 kJ mol^–1). The detonation velocity of compound 8 (9305 ms^–1) approaches that of HMX (9320 ms^–1), which suggests it is a competitive high-energy-density material.

The Nazarov cyclization has been established as a powerful tool in constructing cyclopentenone skeletons. In sharp contrast, oxa-Nazarov cyclization that affords dihydrofuranones, a new type of product, has been less explored. In this work, we report the I₂-catalyzed oxa-Nazarov cyclization-Michael addition cascade between vinyl α-diketones and enones. The protocol allows access to a range of functionalized dihydrofuranones with good to high yields, and diverse further transformations on the products have been achieved. Furthermore, the mechanistic studies reveal that the 1,2-hydride shift occurs simultaneously during the dihydrofuranone formation.

A palladium-catalyzed cascade radical cyclization and carbonylation of 1,7-enynes with perfluoroalkyl iodides and alcohols has been described. This procedure provides a facile and efficient approach for the construction of 3,4-dihydroquinolin-2(1H)-one skeletons by using benzene-1,3,5-triyl triformate (TFBen) as the CO source. This method enables the incorporation of both perfluoroalkyl and carbonyl units into the 3,4-dihydroquinolin-2(1H)-one skeletons, producing a variety of 3,4-dihydroquinolin-2(1H)-one derivatives in moderate to high yields and with excellent E/Z selectivity.

The N-heterocyclic carbene (NHC)-organocatalyzed [3 + 3] annulation of 2-bromoenals with β-oxodithioesters resulting in the enantioselective synthesis of dihydrothiopyranones is presented. The chiral α,β-unsaturated acylazoliums generated from 2-bromoenals and carbenes underwent smooth interception with the sulfur nucleophiles to furnish the sulfur heterocycles in satisfactory yields/selectivity. The regioselective formation of dihydrothiopyranones over the competing dihydropyranones is noteworthy.

Euphylonoids A (1) and B (2), two highly modified jatrophane diterpenoids, were isolated from Euphorbia hylonoma. 1 represents a new 9(10→18)-abeo-8,12-cyclojatrophane skeleton containing a cage-like 3,8-dioxatricyclo[5.1.2.0^4,9]decane core, while 2 is a 14(13→20)-abeo-8,12-cyclojatrophane featuring an unusual 17-oxatetracyclo[12.2.1.0^1,5.0^9,13]heptadecane framework. Their structural elucidation was completed by spectroscopic, chemical, computational, and single-crystal X-ray diffraction means. 2 significantly inhibited early adipogenesis in 3T3-L1 adipocytes via activating AMP-activated protein kinase signaling.

The moiety of 4-imidazolidinone is an important structural motif in organic synthesis and medicinal chemistry. We present the synthesis of 4-imidazolidinones from various diamides with ethynyl benziodoxolones through double Michael-type addition, which is an unprecedented reaction mode for hypervalent alkynyl iodine compounds. cis-2,5-Disubstituted 4-imidazolidinones were diastereoselectively synthesized from amino acid derived diamides. Having derivatized the 4-imidazolidinones, several control experiments and density functional theory calculations were conducted to realize mechanistic insight.

An efficient and straightforward approach for the synthesis of trifluoromethyl-decorated benzo[de][1,8]naphthyridines has been achieved via the Rh(III)-catalyzed dual C–H activation and cascade annulation of benzimidates and CF₃-imidoyl sulfoxonium ylides. The novel transformation involves the formation of four new chemical bonds along with the release of two molecules of dimethyl sulfoxide (DMSO) and one molecule each of ethanol and amine. The optoelectronic properties of the obtained fused aromatic products have been investigated by recording the UV–vis absorption and emission spectra.

A regioselective alkylation of β,γ-alkynyl-α-imino esters by visible-light photocatalysis has been developed. This method enables 1,2-addition of methyl, primary, secondary, and tertiary alkyl radicals to the conjugated imines under mild conditions to produce a variety of quaternary alkynyl α-amino acid and cyclic amino acid motifs. Alkyl radicals are generated from alkyl bis(catecholato)silicates with an organic photocatalyst. This process is effective under an air atmosphere, providing operational benefits compared to conventional alkylation using organometallic reagents.

We herein describe an accessible ligand-controlled nickel-catalyzed tandem isomerization/regiodivergent hydroheteroarylation of α-alkenes with a series of heteroarenes, wherein the NHC ligand of heteroleptic Ni(II) complexes of the type Ni(NHC)[P(OEt)₃]Br₂ displayed significant effects on regulation. In the presence of NaO^tBu, Ni(IMes)[P(OEt)₃]Br₂ enables C═C bond isomerization of α-alkenes over up to four sp³ carbon atoms to afford branched products, while Ni(IPr*^OMe)[P(OEt)₃]Br₂ greatly deactivates α-alkene isomerization and favors the formation of linear products.

A facile Pd-catalyzed cascade of intramolecular Heck cyclization/alkylpalladium activated dearomatization of aryl alkyne-tethered indole is described. In this single step two nonadjacent all-carbon quaternary centers, two nitrogen-containing heterocycles, and three C(sp²)–C(sp³) bonds are efficiently furnished. These products could also undergo 5-to-6 ring migration-expansion reaction under Brønsted-acid conditions to transform into the benzo[c]carbazole skeletons.

We report a general, catalyst-controlled route to prostaglandin F2_α and its analogues. The approach uses a Rh-catalyzed dynamic kinetic asymmetric Suzuki–Miyaura coupling reaction between a racemic bicyclic allyl chloride and alkenyl boronic esters bearing chiral alcohols to give cyclopentyl intermediates bearing 3 contiguous stereocenters. The route provides advanced intermediates in 99% ee as a single diastereoisomer in all cases examined, with the absolute stereochemistry of the cyclopentane core controlled by the ligand. Intermediates that could be used to produce prostaglandin analogues such as bimatoprost, latanoprost, fluprostenol, and cloprostenol were synthesized. The final two stereocenters were installed via Pd-catalyzed Tsuji–Trost alkylation and iodolactonization. The synthesis of PG F2_α was achieved in 19% yield in 16 longest linear steps.

We describe herein a novel synthesis of various homoallylic nitriles via cobalt-catalyzed hydrocyanation of methylenecyclopropanes. Excellent selectivity, mild reaction conditions, good functional group compatibility, gram-scale reaction, and product transformations demonstrate the power of this protocol. This extraordinary selectivity can probably be attributed to the stronger aptitude of the alkyl–cobalt cyanide intermediate to undergo reductive elimination rather than β-hydride elimination.

Herein, we report a facile, efficient, and practical protocol that enables the preparation of aryl xanthates and aryl dithiocarbamates from functionalized dibenzothiophenium salts via a photoactivated electron donor–acceptor complex. This mild, metal-free method is operationally simple and has a broad substrate scope and potential utility for late-stage functionalization of natural products and pharmaceuticals. Finally, this method also has redefined the substrate scope and reaction pathway for the Leuckart thiophenol reaction.

Implementing the use of alkynyllithium reagents in a stereospecific 1,2-metalate rearrangement-mediated ring opening of polysubstituted cyclopropyl boronic esters provides a variety of tertiary pinacol boranes bearing adjacent tertiary or quaternary carbon stereocenters with high levels of diastereomeric purity. The potential of this strategy was demonstrated through a selection of α- and γ-functionalization of the propargyl boronic esters.

Sulfonamide is a common motif in medicines and agrochemicals. Typically, this class of functional groups is prepared by reacting amines with sulfonyl chlorides that are presynthesized from nitro compounds and thiols, respectively. Here, we report a novel strategy that directly couples nitro compounds and thiols to form sulfonamides atom- and redox-economically. Mechanistic studies suggest our reaction proceeds via direct photoexcitation of nitroarenes that eventually transfers the oxygen atoms from the nitro group to the thiol unit.

An electrochemical oxidative sulfoximido-oxygenation of alkenes has been developed by using NH-sulfoximines and alcohols directly. This method proceeds regioselectively without metal catalysts and external chemical oxidants and shows broad substrate scope and diverse functional group compatibility. Based upon the preliminary mechanism studies, N-centered sulfoximidoyl radicals were involved in this electrochemical process.

Herein we describe the pioneering Rh-catalyzed coupling reactions of a fluoroalkyl carbene with azides to access α-trifluoroethylated imines, where fluoroalkyl N-sulfonylhydrazones are used as fluoroalkyl diazo surrogates. Remarkably, using TMSN₃ as the N source, two C–N bond formation products were obtained. Furthermore, the α-trifluoroethylated imine products could be easily reduced to the corresponding N-trifluoroethylated anilines. Experimental results and theoretical calculations justify a stepwise reaction pathway involving the formation of rhodium carbene, the addition of HN₃, and C═N bond formation.

A single-flask cascade of Michael addition and Wittig olefination was developed to allow the stereoselective α-allylic alkylation of α-branched N-tert-butanesulfinyl ketimines for the construction of acyclic quaternary stereocenters bearing two sterically and electronically similar substituents. In this process, tBuOK-promoted stereoselective α-deprotonation gives fully substituted aza-enolates with a stereodefined geometry, Michael addition with α,β-unsaturated phosphonates generates C–C bonds with exceptional stereocontrol, and finally paraformaldehyde trapping of the conjugate addition intermediate generates functionalized α-allylated imines.