Rhodium-catalyzed C–H activation and conjugate addition under mild conditions

An efficient rhodium^III-catalyzed C–H activation and subsequent conjugate addition was achieved under mild conditions. The reaction utilized inert arenes to replace stoichiometric organometallic reagents and can tolerate various functional groups as well as air and water.

Nickel-catalyzed sp2 C–H bonds arylation of N-aromatic heterocycles with Grignard reagents at room temperature

A novel protocol for nickel-catalyzed direct sp² C–H bond arylation of purines has been developed. This new reaction proceeded efficiently at room temperature using Grignard reagent as the coupling partner within 5 hours in good to high yields. This approach provides a new access to a variety of C8-arylpurines which are potentially of great importance in medicinal chemistry.

Chem. Commun., 2011, 47, 11140-11142

Efficient and highly selective iron-catalyzed reduction of nitroarenes

Pyrolysis of iron–phenanthroline complexes supported on carbon leads to highly selective catalysts for the reduction of structurally diverse nitroarenes to anilines in 90–99% yields. Excellent chemoselectivity for the nitro group reduction is demonstrated.

Chem. Commun., 2011, 47, 10972-10974

Palladium-catalysed hydroxylation and alkoxylation

The formation of oxygen–carbon bonds is one of the fundamental transformations in organic synthesis. In this regard the application of palladium-based catalysts has been extensively studied during recent years. Nowadays it is an established methodology and the success has been proven in manifold synthetic procedures. This tutorial review summarizes the advances on palladium-catalysed C–O bond formation, means hydroxylation and alkoxylation reactions.

Transition metal-catalyzed arylation of unactivated C(sp3)–H bonds

Transition-metal-catalyzed C–H bond arylation has recently emerged as a powerful tool for the functionalization of organic molecules that may complement or even replace traditional catalytic cross-couplings. While many efforts have focused on the arylation of arenes and heteroarenes in the past two decades, less studies have been devoted to the arylation of nonacidic C–H bonds of alkyl groups. This tutorial review highlights recent work in this active area.

Pyridinyl Directed Alkenylation with Olefins via Rh(III)-Catalyzed C–C Bond Cleavage of Secondary Arylmethanols

Zhang-Jie Shi, JACS 2011

C–H Arylation of Pyridines: High Regioselectivity as a Consequence of the Electronic Character of C–H Bonds and Heteroarene Ring

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Dalibor Sames, JACS, 2011.

Carboxylic Acids as Traceless Directing Groups for Formal meta-Selective Direct Arylation

1. Dr. Igor Larrosa, 2011, Angew Chem Int Ed.

Palladium(II)-Catalyzed Selective Monofluorination of Benzoic Acids Using a Practical Auxiliary: A Weak-Coordination Approach

Finally, a choice! A highly selective palladium(II)-catalyzed ortho-monofluorination reaction has been achieved for the first time through a weak coordination (see scheme; Ar=2,3,5,6-tetrafluoro-4-(trifluoromethyl)phenyl). Simple modification of this protocol allows for a choice between mono- and difluorination. The mono- and difluorinated benzoic acid derivatives are valuable in the pharmaceutical and agrochemical industries.

1.  
2. Prof. Dr. Jin-Quan Yu, Angew. Chem. Int. Ed, 2011. doi; 10.1002/anie.201102985

Copper-Mediated Cyanation of Aryl Halide with the Combined Cyanide Source

A simple copper-mediated cyanation of aryl halide with the combination of ammonium bicarbonate and N,N-dimethylformamide as a cyanide source is achieved, providing nitriles in moderate to good yields. This new approach represents an exceedingly practical and safe method for the synthesis of aryl nitriles.

Aryl Trihydroxyborate Salts: Thermally Unstable Species with Unusual Gelation Abilities

A series of aryl trihydroxyborate salts were synthesized and found to form gels in benzene. The compounds were thermally unstable and readily underwent protodeboronation in solution and the solid state. Gelation could be induced without decomposition via sonication. Subsequent characterization studies revealed an unusual dependence of gel properties on alkyl chain length.

Nickel-Catalyzed Chelation-Assisted Transformations Involving Ortho C–H Bond Activation

Although the pioneering example of ortho metalation involving cleavage of C–H bonds was achieved using a nickel complex (Kleiman, J. P.; Dubeck, M. J. Am. Chem. Soc. 1963, 85, 1544), no examples of catalysis using nickel complexes have been reported. In this work, the Ni-catalyzed transformation of ortho C–H bonds utilizing chelation assistance, such as oxidative cycloaddition of aromatic amides with alkynes, has been achieved.

Rhodium-catalyzed direct ortho C–H olefination of phenol derivatives

Cationic rhodium complex-catalyzed olefination of phenol derivatives for the direct introduction of an α,β-unsaturated ester appendage is described. In addition, deuterium labelling and kinetic isotope effect studies were performed to probe the reaction mechanism.

Chao Feng and Teck-Peng Loh 

Chem. Commun., 2011, 47, 10458-10460

Regiocontrolled aerobic oxidative coupling of indoles and benzene using Pd catalysts with 4,5-diazafluorene ligands

Palladium-catalyzed aerobic oxidative cross-couplings of indoles and benzene have been achieved by using 4,5-diazafluorene derivatives as ancillary ligands. Proper choice of the neutral and anionic ligands enables control over the reaction regioselectivity.

Chem. Commun., 2011, 47, 10257-10259

Synthesis of Phenanthridinones from N-Methoxybenzamides and Arenes by Multiple Palladium-Catalyzed C[BOND]H Activation Steps at Room Temperature