Transition-Metal-Free Direct Arylation of Anilines

Combined Oxypalladation/C[BOND]H Functionalization: Palladium(II)-Catalyzed Intramolecular Oxidative Oxyarylation of Hydroxyalkenes

Discovery of a Full-Color-Tunable Fluorescent Core Framework through Direct C[BOND]H (Hetero)arylation of N-Heterocycles

Oxidative Trifluoromethylation of Arylboronates with Shelf-Stable Potassium (Trifluoromethyl)trimethoxyborate

Enantioselective construction of quaternary N-heterocycles by palladium-catalysed decarboxylative allylic alkylation of lactams

The enantioselective synthesis of nitrogen-containing heterocycles (N-heterocycles) represents a substantial chemical research effort and resonates across numerous disciplines, including the total synthesis of natural products and medicinal chemistry. In this Article, we describe the highly enantioselective palladium-catalysed decarboxylative allylic alkylation of readily available lactams to form 3,3-disubstituted pyrrolidinones, piperidinones, caprolactams and structurally related lactams. Given the prevalence of quaternary N-heterocycles in biologically active alkaloids and pharmaceutical agents, we envisage that our method will provide a synthetic entry into the de novo asymmetric synthesis of such structures. As an entry for these investigations we demonstrate how the described catalysis affords enantiopure quaternary lactams that intercept synthetic intermediates previously used in the synthesis of the Aspidosperma alkaloids quebrachamine and rhazinilam, but that were previously only available by chiral auxiliary approaches or as racemic mixtures.

Nature Chemistry (2011) doi:10.1038/nchem.1222

Key Mechanistic Features of Enantioselective C–H Bond Activation Reactions Catalyzed by [(Chiral Mono-N-Protected Amino Acid)–Pd(II)] Complexes

A New Reagent for Direct Difluoromethylation

Phil S. Baran, JACS, 2012, DOI: 10.1021/ja211422g

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Sildenafil (Viagra)

Sildenafil, trade name VIAGRA, chemical name 5-[2-ethoxy-5-(4-methylpiperazin-1-ylsulfonyl)phenyl]-1- methyl-3-propyl-1,6-dihydro-7H-pyrazolo[4,3-d]pyrimidin-7-one, formula C22H30N6O4S, was discovered through a rational drug design programme by the pharmaceutical company Pfizer. It is a potent selective inhibitor of the enzyme phosphodiesterase (PDE-5), which destroys cyclic guanosine monophosphate (cGMP), itself a dilator of blood vessels in the body. Viagra thus allows cyclic GMP to persist and this property has led to its use for the oral treatment of male erectile dysfunction (N. K. Terrett, A. S. Bell, D. Brown, P. Ellis Bioorganic & Medicinal Chem. Lett., 1996, 6, pp.1819-1824). It is adminstered as the citrate.

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A phosphine-free Pd catalyst for the selective double carbonylation of aryl iodides

The first phosphine-free Pd-catalysed double carbonylation of aryl iodides is reported as a general and practical method, giving excellent conversions and selectivities for a wide range of aryl iodides and amine nucleophiles under atmospheric CO pressure.

Rhodium catalyzed C–H olefination of N-benzoylsulfonamides with internal alkenes

An annulation via tandem rhodium catalyzed C–H olefination of N-benzoylsulfonamides with internal olefins followed by C–N bond formation is disclosed. A N-substituted quaternary center is formed during the reaction thus providing efficient access to a series of 3,3-disubstituted isoindolinones.

“Rollover” cyclometalation – early history, recent developments, mechanistic insights and application aspects

“Rollover” cyclometalation constitutes a special case among the well-known class of cyclometalation reactions. An overview is given that covers the very first description of this reaction type, as well as recent developments. In addition, not only condensed-phase experiments are reviewed, but also investigations based on mass spectrometric techniques, together with “in silico” studies using DFT-based calculations are considered. While the latter two methods allow for a detailed analysis of the intrinsic factors that affect the reaction mechanisms, consideration of all three regimes permits to develop a coherent mechanistic picture and to address the often noted gap between condensed- and gas-phase studies. Moreover, the quite unexpected reactivity of “rollover” cyclometalated complexes in gas-phase experiments, as well as potential applications, e.g. in synthetic procedures, are discussed in some detail.

Copper-catalyzed direct oxidative synthesis of α-ketoamides from aryl methyl ketones, amines, and molecular oxygen

A novel and efficient copper-catalyzed direct oxidative synthesis of α-ketoamides from aryl methyl ketones, amines, and molecular oxygen has been developed under mild and neat conditions. ¹⁸O labeling experiments revealed that both oxygen atoms of the α-ketoamides derived from molecular oxygen.

Copper-catalyzed direct oxidative synthesis of α-ketoamides from aryl methyl ketones, amines, and molecular oxygen

The author report an intermolecular hydroacylation of allylic alcohols with salicylaldehydes to afford β-hydroxy aryl ketones in 73–94% yields as single regioisomers. The reactivity and regioselectivity were promoted by catalytic amounts of a phosphinite that forms a dynamic covalent bond with the allylic alcohol. Hydroacylation of 1,2- and 1,1-disubstituted olefins generates β-hydroxy aryl ketones bearing tertiary and quaternary centers, respectively.

NMR Chemical Shifts of Trace Impurities

A wonderful paper for all chemist. If you didn't already spot this useful paper on NMR impurities you should go get it now. An excellent addition to the classic paper by Gottlieb et al. that you can access here.

Supporting Information file

Copper-Catalyzed Aerobic Oxidative Intramolecular C–H Amination Leading to Imidazobenzimidazole Derivatives