Themed collection HOT articles in Organic Chemistry Frontiers in 2016

A bisbutadiyne bridged azahelicene dimer with a figure-eight shape, which exhibited both high fluorescence quantum yield and CPL properties, has been synthesized through the Glaser–Hay homo-coupling reaction with diethynylazahelicene.

The mechanism of C–H cyanation of 2-phenylpyridine with 2-phenylacetonitrile catalyzed by the CuBr catalyst was elaborated based on DFT calculations.

This is the first example of using only a catalytic amount of silyl-EBX in a dehydration reaction since its discovery. Preliminary mechanistic studies ruled out the radical pathways and supported an E1 process.

The stability and reactivity of tri-, di- and monofluoromethyl groups under acidic and basic conditions are described.

The title compounds, including the parent 3-azido-2H-azirine, were generated by low-temperature photolysis of the corresponding 1,1-diazidoethenes, and characterised not only by trapping reactions, but also by direct detection using NMR and in situ IR spectroscopy.

A copper-mediated annulation of 2-(1-substituted vinyl)anilines and aryl nitrosos is developed, giving 2,3-diaryl pyrazoles in moderate to good yields.

A highly efficient copper(I)-catalyzed asymmetric 1,3-dipolar cycloaddition was developed, which provides a straightforward and efficient pathway to highly functionalized free pyrrolidine β-amino acids.

o-(Diphenylphosphino)benzaldehyde has been identified as the effective ligand for the coupling of propargylic carbonates and organoboronic acids under mild conditions.

A Rh(I)-catalyzed cross-coupling of 2-bromoethyl aryldiazoacetates with tertiary propargyl alcohols has been successfully achieved.

A carbene precursor plays a dual role as both an organocatalyst and as a ligand for the copper catalyst in asymmetric silylation.

A highly efficient manganese-catalysed hydroperoxidation of carbon–carbon double bonds of enynes as well as styrene derivatives using N-hydroxyphthalimide, N-hydroxybenzotriazole or N-hydroxysuccinimide was developed.

The present work describes the unprecedented use of Fluoroalkyl Amino Reagents (FARs) to afford 2,4-bis(fluoroalkyl)-substituted quinoline derivatives in two steps under mild reaction conditions, in good yields and with a very good regioselectivity.

Polypropionates are synthesized using a combination of a copper-catalyzed asymmetric allylic alkylation, ruthenium-catalyzed cross-metathesis and iridium-catalyzed asymmetric allylic etherification.

A new Pd-catalyzed alkene carboalkoxylation strategy for the preparation of 2,3-dihydrobenzofurans is described.

Switching between the intermolecular reaction and the intramolecular reaction was achieved at will using flow microreactors.

Careful consideration of the chemical mechanism for an oxidative condensation reaction led to improved current flow for the electrolysis.

Catalytic asymmetric 1,4-addition reactions of simple esters have been developed. The desired reactions proceeded smoothly with high enantioselectivities.

Benzylamines undergo C–H activation and aerobic coupling with diazo compounds, leading to the synthesis of fused isoquinolines. This occurs via a mild synergistic rhodium- and copper-catalyzed process.

A novel supramolecular polymer was constructed between Q[14] host and 5,10,15,20-tetrakis(N-butyl-4-pyridinium)porphyrin tetrabromide guest depending on the host–guest interactions, representing the first cucurbit[14]uril-involved host–guest supramolecular polymer.

An iterative asymmetric hydration of dienoates approach to Leucasndrolide A was explored.

Pd-catalyzed difluoroallylation of unactivated C(sp²)–H bonds with readily available R_f-Br reagents is described.

A series of complex polycyclic ethers have been synthesised under very mild conditions using a low catalyst loading of bismuth(III) triflate.

A versatile cascade route to cyclic imides via direct functionalization of the β-alkenyl C–H bond of alkenoic acids was developed.

A supramolecular polyrotaxane constructed by pillar[5]arene-based pseudo[2]rotaxanes via the incorporation of metal–ligand coordination could further self-assemble to form a stimuli-responsive supramolecular gel at high concentration.

Cu(II)-mediated arene C–H bond trifluoromethylthiolation with Me₄NSCF₃ proceeds via arylcopper(III) intermediates to produce functionalized azacalix[1]arene[3]pyridine macrocycles.

A photochemical borylation of electron-rich aryl (pseudo)halides via a triplet aryl cation mechanism has been described.

2,5-Disubstituted pyrroles are synthesized by acceptorless dehydrogenative reaction of 1,2-aminoalcohols and secondary alcohols by Pt/carbon catalyst.

The first metal-free, initiator-free, and general photochemical perfluoroalkylation of a variety of N,N-dialkylhydrazones was developed at room temperature in the absence of any external photocatalyst.

The highly efficient asymmetric α-amination of β-keto esters and β-keto amides was realized by using a chiral N,N′-dioxide/Cu(I) complex. Under mild reaction conditions, a series of chiral α-amino dicarbonyl compounds were obtained in good result.

A series of novel chiral monophosphine ligands Xiang-Phoses were designed and have been applied to the enantioselective gold-catalyzed intermolecular [2 + 2]-cycloaddition of 3-styrylindoles 1 with N-allenyl oxazolidinone 2.

A synthetic method to carbamates from amines and N-tosylhydrazones in the presence of 1 atm of carbon dioxide was developed.

The scaffold of benzo[b]thiophene 1,1-dioxides can be easily constructed through a copper(I)-catalyzed insertion of sulfur dioxide into (2-alkynylaryl)boronic acids. The reaction proceeds via insertion of sulfur dioxide and subsequent intramolecular 5-endo cyclization.

A catalyst-free aminosulfonylation through insertion of sulfur dioxide with aryl/alkyl halides enabled by photoenergy is presented. Under ultraviolet irradiation, a three-component reaction of aryl/alkyl halides, sulfur dioxide, and hydrazines proceeds under mild conditions without any metals or photo-redox catalysts.

Diastereoselective Friedel–Crafts reactions of optically pure epoxy enolsilanes afford enantiomerically-enriched β-hydroxy-α-arylketones. Aziridinyl enolsilanes react in an analogous manner.

A simple and efficient visible-light promoted intermolecular haloamination and haloetherification of alkenes was reported.

A Pd(II)-catalyzed selective β-arylation of O-methyl ketoximes was developed using iodoarenes as the coupling partners.

The Au-catalyzed tandem reaction provided simple and efficient access to spiro-dipyrroloquinolines and incargranine B aglycone and (±)-seneciobipyrrolidine (I).

A palladium/norbornene-catalyzed ortho-C–H alkylation and ipso-alkynylation reaction for the synthesis of 2-alkyl-1-alkynyl arenes was reported, where the use of bulky 1,1-dimethyl-2-alkynols led to significant suppression of the formation of O-alkylation and norbornene alkynylation by-products.

The intramolecular aza-(4 + 3) cycloaddition reactions of in situ generated aza-oxyallylic cations and furans have been reported for the construction of medium sized hydroxamate macrocycles.

The synthesis of strained paracyclophanes is facilitated by ortho-substitution effect on phenyl ring.