Rh(III)-Catalyzed C-H Bond Addition/Amine-Mediated Cyclization of Bis-Michael Acceptors

Rhodium(III)-Catalyzed C-H Activation: A Cascade Approach for the Regioselective Synthesis of Fused Heterocyclic Lactone Scaffolds

A Rh(III)-catalyzed cascade C-H activation; regioselective [4 + 2] oxidative annulation; and lactonization of aromatic acids, anhydrides, and acrylic acid derivatives with 4-hydroxy-2-alkynoates have been disclosed. This strategy leads to fused heterocyclic lactone scaffolds in a single step with moderate functional group tolerance and excellent site selectivity. Besides, in one step, an antipode of the cephalosol intermediate natural product that contains a tricyclic isocoumarin framework has been synthesized.

Trisannulation of benzamides and cyclohexadienone-tethered 1,1-disubstituted allenes initiated by Cp*Rh(iii)-catalyzed C–H activation

A trisannulation of benzamides and cyclohexadienone-tethered 1,1-disubstituted allenes was achieved via the initiation of Cp*Rh(iii)-catalyzed C–H bond activation.

A comprehensive overview of directing groups applied in metal-catalysed C-H functionalisation chemistry

The present review is devoted to summarizing the recent advances (2015-2017) in the field of metal-catalysed group-directed C-H functionalisation. In order to clearly showcase the molecular diversity that can now be accessed by means of directed C-H functionalisation, the whole is organized following the directing groups installed on a substrate. Its aim is to be a comprehensive reference work, where a specific directing group can be easily found, together with the transformations which have been carried out with it. Hence, the primary format of this review is schemes accompanied with a concise explanatory text, in which the directing groups are ordered in sections according to their chemical structure. The schemes feature typical substrates used, the products obtained as well as the required reaction conditions. Importantly, each example is commented on with respect to the most important positive features and drawbacks, on aspects such as selectivity, substrate scope, reaction conditions, directing group removal, and greenness. The targeted readership are both experts in the field of C-H functionalisation chemistry (to provide a comprehensive overview of the progress made in the last years) and, even more so, all organic chemists who want to introduce the C-H functionalisation way of thinking for a design of straightforward, efficient and step-economic synthetic routes towards molecules of interest to them. Accordingly, this review should be of particular interest also for scientists from industrial R&D sector. Hence, the overall goal of this review is to promote the application of C-H functionalisation reactions outside the research groups dedicated to method development and establishing it as a valuable reaction archetype in contemporary R&D, comparable to the role cross-coupling reactions play to date.

Divergent Coupling of Anilines and Enones by Integration of C-H Activation and Transfer Hydrogenation

Cp*Rh^III /Ir^III complexes are known to play important roles in both C-H activation and transfer hydrogenation (TH). However, these two areas evolved separately. They have been integrated in redox- and chemodivergent coupling reactions of N-pyridylanilines with enones. The iridium-catalyzed coupling with enones leads to the efficient synthesis of tetrahydroquinolines through TH from ⁱ PrOH. Counterintuitively, ⁱ PrOH does not serve as the sole hydride source, and the major reaction pathway involves disproportionation of a dihydroquinoline intermediate, followed by the convergent and iterative reduction of quinolinium species.

Rhodium-catalyzed triazole-directed C–H bond functionalization of arenes with diazo compounds

Rhodium(iii)-catalyzed alkylation reactions of arenes through triazole directed C–H activation that lead to a number of dialkylated and monoalkylated triazoles are described.

Rhodium(III)-Catalyzed Oxadiazole-Directed Alkenyl C-H Activation for Synthetic Access to 2-Acylamino and 2-Amino Pyridines

We report herein a Rh(III)-catalyzed alkenyl C-H activation protocol for the coupling of oxadiazoles with alkynes and synthesis of 2-acylamino and 2-amino pyridines, an important heterocyclic scaffold for various naturals products and synthetic pharmaceuticals bearing a readily reacting functional group. The selective protection/deprotection of amino groups through simple solvent switching, good functional group compatibility, superior product yield, and high regioselectivity are some of the notable synthetic features witnessed in this reaction protocol.