Search

Theoretical studies predict that the introduction of nitrogen atoms onto cycloparaphenylene frameworks would add fascinating properties but few partially N-doped carbon nanorings have been synthesized. Here, the authors report the synthesis of a cycloparaazine, where every para-connected aromatic moiety consists of a N-heterocycle, and two other highly N-doped carbon nanorings.

Ring-expanding carbon-atom insertion reactions are currently limited to the installation of few functional groups. Now researchers show the use of a radical carbyne precursor for the insertion of carbon atoms bearing varied functional groups to access 2-substituted naphthalenes from indene.

C to N atom swapping in indoles is introduced that gives indazoles through oxidative cleavage of the indole heteroarene core and subsequent ring closure, adding another method to the field of skeletal editing.

Hypervalent iodine catalysis remains a powerful method to enable geminal difluoromethylenation of alkenes. However, the scope is mainly limited to styrene derivatives. Now, enynes have been validated as competent substrates where a formal 1,2-shift of the alkyne occurs, thereby enabling highly versatile homopropargylic difluorides to be generated.

Irradiation of chiral Al-salen complexes with violet light demonstrates efficient deracemization of cyclopropanes, enabling reactivity and enantioselectivity to be regulated simultaneously, negating the requirement for tailored catalyst–substrate recognition motifs.

A strain-release approach, realized by visible-light-mediated triplet energy transfer catalysis, enabled an intermolecular [2π+2σ]-photocycloaddition.

Methods to allow access to all isomers of a product are both valuable and challenging to achieve. Here the authors report a catalytic system comprised of an N-heterocyclic carbene and an iridium complex, and show that it can be used for the asymmetric, diastereodivergent synthesis of γ-butyrolactones.

An iron-catalysed radical Markovnikov hydroamidation of alkenes using a cyanamide reagent is reported. The method achieves C–N bond formation with high yields and selectivity and is applicable to a wide range of alkenes and natural products. The cyanamide functionality can be transformed into various functional groups, highlighting its potential for advanced applications in natural product synthesis.

Heteroatom-substituted C(sp³)-rich polycyclic hydrocarbon rings, isosteric to heterocyclic rings, are not common due to the challenging synthesis. Now a photoredox-catalysed strategy to insert amidyl radicals into bicyclo[1.1.0]butanes is presented, providing direct access to 2-oxa-4-azabicyclo[3.1.1]hept-3-enes.

Alkenes are attractive building blocks for synthetic organic chemists as they are widely available and can be functionalized in ways that enable manifold further transformations. Here, the authors present a suite of hydrofunctionalizations of alkenes that lead to regioselective delivery of azides and halogens, under mild conditions, with iron catalysis.

gem-Difluorinated motifs are prevalent in numerous leading pharmaceuticals. Here the authors merge I(I)/I(III)-catalysed fluorination and C(sp3)-F bond activation to generate these motifs directly from 1,3-diaryl cyclobutanols in a single operation.

Controlling selectivity during direct unsymmetrical diamination of double bonds is challenging. Now, ambiphilic iminyl and electrophilic amidyl radicals are generated from oxime ester-based bifunctional precursors, enabling the regio- and diastereoselective unsymmetrical diamination of arenes and alkenes.

The majority of methods to prepare β-amino acid derivatives require metal-mediated multistep manipulations of pre-functionalized substrates. Now, a metal-free, energy-transfer enabled, highly regioselective aminocarboxylation reaction has been developed, for the single-step installation of both amine and ester functionalities into alkenes or (hetero)arenes. An oxime oxalate ester is used as a bifunctional reagent, supplying C-centred ester and N-centred iminyl radicals.

General methods to regioselectively introduce both amine and alcohol functionalities into alkene substrates to afford 1,2-aminoalcohols in a single step are lacking. Now, this has been addressed by a metal-free photosensitization strategy using oxime carbonate as a suitable bifunctional reagent.

Hybrid 2D/3D ring systems have emerged as important scaffolds in medicinal chemistry, but efficient protocols for their synthesis are scarce. Now, energy-transfer-mediated cascade dearomative [2 + 2] cycloaddition/rearrangement reactions are developed to provide facile access to pyridine-fused 2D/3D ring systems.

Catalysis with N-heterocyclic carbenes produces diverse outcomes depending on which of the many possible reaction mechanisms dominates. Control of this reactivity within a single reaction type has rarely been demonstrated. Now, starting from identical substrates, a switchable catalytic activation is shown to afford different products with high regio- and stereoselectivity.