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In drug discovery, the preparation of analogues with diverse core structures often requires laborious efforts. Now it has been shown that 1,2-oxaborines, which are synthesized from readily available starting materials, can serve as a versatile platform to allow rapid access to diverse central skeletons, thus simplifying the core diversification process.

Directing group strategies for selective dearomatization of unactivated aromatic π-systems have remained elusive. Now a homogeneous ruthenium catalyst, aided by a removable directing group, enables the site-selective hydrogenation of less reactive arene moieties in polyaryl compounds.

The ideal in organic synthesis is to prepare complex molecules using the smallest possible number of steps. Also important is atom economy, limiting waste by ensuring that most of atoms present in the reactants end up in the product. This paper demonstrates both of these principles to great effect in the synthesis of bryostatin 16, a biologically active, naturally occurring compound. The synthesis uses nearly half the number of steps of previously reported routes to bryostatins.

A nickel-catalysed vicinal diborylation method is described, which can install two different boron functional groups on aromatic rings in a regioselective and site-selective manner, enabling the rapid synthesis of complex molecular building blocks.

We report an S_NV reaction, a rare nucleophilic substitution that involves electronically unbiased vinyl electrophiles, which allows the synthesis of cross-conjugated polyenes and bioactive compounds with multi-substituted alkenes.

Unstrained aryl–aryl bonds are among the most inert bonds in organic chemistry. Now the development of a split cross-coupling strategy enables the direct functionalization of such bonds through Rh-catalysed C–C cleavage and cross-coupling with aryl halides, providing a method for biaryl synthesis.

In the chemical industry, it is often necessary to activate carbon–carbon bonds in order to synthesize complex organic molecules, but this is challenging when starting with simple five- or six-membered carbon rings; a new method uses a rhodium pre-catalyst and an amino-pyridine co-catalyst, enabling an overall energetically favourable reaction that involves activation of carbon–carbon bonds plus activation of carbon–hydrogen bonds.

Preparation of monocyclic 1,2-azaborines, a unique class of benzene isosteres, has been challenging. Now, an efficient and modular method has been developed to access diverse multi-substituted 1,2-azaborines from readily available cyclopropyl imines/ketones and dibromoboranes. The reaction goes through an unusual ring-opening BN-isostere benzannulation mechanism.

Poly-substituted aromatic sulfur compounds are part of many pharmaceuticals, agrochemicals and organic materials. Here, the authors developed a sulfenamide-enabled ortho-thiolation of aryl iodides via Pd/norbornene cooperative catalysis for the preparation of polysubstituted aromatic sulfur compounds.

Common native functional groups would be appealing as handles to enable C–H annulation with diverse aromatic rings. Now, this is achieved using ketones as unconventional alkyl radical precursors providing a practical method to synthesize biologically important fused-ring systems.

Effective band-gap engineering of armchair graphene nanoribbons calls for control over both width and edge structure. Here, the authors report a modular synthesis of narrow N = 6 armchair graphene nanoribbons whose edges can be unsymmetrically modified with heteroarenes, introducing a simple way to tune band gap.

Although widely used to form bridged ring systems, certain intramolecular Diels–Alder reactions are hampered by the strain inherent in forming an sp²-carbon at a bridgehead position. Now, an alternative strategy has been described to access these bridged ring systems through the C–C activation and coupling of cyclobutanones with olefins.

The genome sequence and its analysis of the diploid wild wheat Triticum urartu (progenitor of the wheat A genome) represent a tool for studying the complex, polyploid wheat genomes and should be a valuable resource for the genetic improvement of wheat.

An enantioconvergent approach for direct asymmetric insertion of racemic carbon-, oxygen-, nitrogen-, sulfur- and silicon-substituted carbenoids into carbon–boron bonds is reported, enabled by a class of chiral β-amino alcohol auxiliaries. In addition, iterative asymmetric homologation offered by this method simplifies syntheses of complex molecules containing multiple stereocentres.

Aromatization-driven C–C bond activation through iridium/phosphine catalysis enables deacylative transformations in various ketone substrates.

All-carbon tetrasubstituted olefins are challenging to prepare in a regio- and stereocontrolled fashion. Now, using an amide-substituted norbornene as a co-catalyst, alkenyl halide- or triflate-mediated palladium/norbornene (Pd/NBE) catalysis has been demonstrated, providing an efficient strategy for modular and regioselective construction of all-carbon tetrasubstituted olefins.

Electrophilic aromatic substitution (EAS) favours arene functionalization at positions meta to electron-withdrawing groups and para to electron-donating groups. Now, with a class of bridgehead-modified norbonene derivatives that can overcome the ortho constraint typical in palladium/norbornene catalysis, arene functionalization with site-selectivity complementary to EAS approaches can be achieved.

Pd/norbornene cooperative catalysis provides a strategy for arene functionalization, but the electrophile scope is typically limited to ‘soft’ elements such as carbon, nitrogen and sulfur. Now the ortho-C–H methoxylation of aryl halides has been realized using a polarity-reversed N−O reagent and facilitated by a C7-bromo-substituted norbornene mediator.

Homologation of organoboronates by iterative carbenoid insertion is an effective method for the synthesis of alkyl chains, but the corresponding homologation using vinyl units remains elusive. Now, a stereoselective vinylene homologation reaction is reported, comprising diastereoselective successive insertion of silyl- and alkoxy-substituted carbenoids into organoboronates, followed by a Peterson-type elimination.

Metathesis reactions involving carbon–carbon double bonds have been well established, but direct metathesis of carbon–carbon single bonds is extremely rare. Now, a ruthenium-catalysed carbon–carbon single-bond metathesis reaction has been developed with unstrained homo-biaryl substrates. The reaction shows wide functional group tolerance and operates via an ‘olefin-metathesis-like’ mechanism.

Catalytic activation of non-polar unstrained C−C bonds remains challenging. Now, the C(aryl)−C(aryl) bonds in 2,2′-biphenols can be cleaved using phosphinites as a recyclable directing group through a rhodium-based spirocyclic intermediate. In particular, the biaryl linkage found in softwood lignin could be cleaved using this method.

The late-stage functionalization of unactivated C(sp³)−H bonds could be useful for the rapid development of structure–activity relationships, but highly target-specific conditions make it challenging. Now, a strategy for the preparation of a variety of β-functionalized alcohol derivatives through a site-selective C−H sulfonyloxylation and subsequent S_N2 reactions is described.

Selective manipulation of carbon–carbon bonds provides a direct approach to editing organic scaffolds. This Review describes the catalytic activation of unstrained carbon–carbon bonds enabled by temporary or removable directing groups.