Highly functionalized benzo[b]phosphole oxides were synthesized from reactions of arylphosphine oxides with alkynes under photocatalytic conditions by using eosin Y as the catalyst and N-ethoxy-2-methylpyridinium tetrafluoroborate as the oxidant. The reaction works under mild conditions and has a broad substrate scope. Mechanistic investigations have been undertaken and revealed the formation of a ground state electron donor-acceptor complex (EDA) between eosin (the photocatalyst) and the pyridinium salt (the oxidation agent). This complex, which has been fully characterized both in the solid state and in solution, turned out to exhibit a dual role, i.e., the oxidation of the photocatalyst and the formation of the initiating radicals, which undergoes an intramolecular reaction avoiding the classical diffusion between the two reactants. The involvement of ethoxy and phosphinoyl radicals in the photoreaction has unequivocally been evidenced by EPR spectroscopy.

We describe the synthesis of new cationic tricoordinated copper complexes bearing bidentate pyridine-type ligands and N-heterocyclic carbene as ancillary ligands. These cationic copper complexes were fully characterized by NMR, electrochemistry, X-ray analysis, and photophysical studies in different environments. Density functional theory calculations were also undertaken to rationalize the assignment of the electronic structure and the photophysical properties. These tricoordinated cationic copper complexes possess a stabilizing CH-π interaction leading to high stability in both solid and liquid states. In addition, these copper complexes, bearing dipyridylamine ligands having a central nitrogen atom as potential anchoring point, exhibit very interesting luminescent properties that render them potential candidates for organic light-emitting diode applications.

We report a new procedure for the preparation of NH-sulfoximines from sulfides using PIDA as an oxidant and ammonium carbamate as the ammonia source. Excellent yields were obtained with a wide range of sulfides. The formation of acetoxy- and methoxy-λ-sulfanenitrile as intermediates was proposed, both of which were converted to the NH-sulfoximine by the action of the solvent. The structure of these intermediates was confirmed by H,C and N NMR and HRMS analysis.

Alkylation of ketones usually involves halides or pseudohalides such as tosylate and triflate derivatives in the presence of a stoichiometric amount of as trong base. [1] Such methodology generates wastes, as all these electrophiles are prepared from alcohols, and requires the use of hazardous chemical materials. Synthetic chemists seek nowadays for more environmentally friendly ways to construct carbon-carbon bonds. In recent years, several efficient strategies were proposed for their creation:i )directly from two simple carbon-hydrogen bonds (catalytic dehydrogenative cross-coupling reaction), [2] andi i) from ketonesa nd alcohols (hydrogen autotransfero rb orrowing hydrogen strategy). [3] Carbon-carbon bond formation via the borrowing hydrogen strategy is ap owerful strategy for the alkylation of ketones (Scheme1). [3] Advantages of this approach are the use of easily-to-handle alcohols, asasourceo fa lkylating reagents, andt he formationo fw ater as the sole byproduct. Indeed, following as implified mechanism,t he alcohol is initially oxidized (dehydrogenation step), and then an aldolizationdehydration step liberates an enone intermediate, whichc an be reduced into ak etone (Scheme 1).Many efficient catalysts are based on expensive noble metals such as iridium, [4] ruthenium [5] or rhodium. [6] Owing to economic constraint and sustainability concerns,t he replacement of platinum metals by first-row-based metals could be an attractive alternative. Recent reports described the use of iron, [7] cobalt [8] and manganese [9] as non preciousm etals in hydrogen autotransfer processes. However,a ll these complexes requiredat emperature threshold of 140 8Ca nd/ore xpensive phosphine ligands. The scope of substrates could also be rather limited. As example, Darcel and co-workers showed recently that only aromatic ketones could be engaged in alkylation reactions in the presence of an in situ iron catalystg enerated from Knçlker's complex and triphenylphosphine. [10] Moreover,y ields were moderate andn om echanism was proposed. [11] Then, even if these works pavet he way to new opportunities in sustainable chemistry,s omel imitationsw ere still present,amechanistic understanding of this iron-catalyzed alkylation reaction and someimprovementwere needed.In our ongoing work on iron-catalyzed reduction, [12] we have recently brought to light that cyclopentadienone iron tricar-Cyclopentadienone iron dicarbonyl complexes were applied in the alkylation of ketones with variousa liphatic and aromatic ketones and alcohols via the borrowing hydrogen strategy in mild reactionc onditions. DFT calculations and experimental works highlight the role of the transition metal Lewis pairs and the base. These iron complexes demonstrated ab road applicability in mild conditions and extended the scope of substrates.Scheme1.Simplified acceptedm echanism of alkylation of ketones.

The development of efficient and low-cost catalytic systems is important for the replacement of the robust noble metal complexes. A highly efficient, stable, phosphine-free, and easy-tosynthesize iron catalyst system for the reduction of CO 2 , hydrogenocarbonate, and carbonate in pure water is reported. In the presence of the bifunctional cyclopentadienone iron tricarbonyl Fe4a− d, the hydrogenation of carbonic derivatives proceeds in good yields with good catalyst productivity. Turnover numbers (TON) of up to 3343, 4234, and 40 for the hydrogenation of CO 2 , hydrogenocarbonate, and carbonate, respectively, to formate in pure water were achieved. For the CO 2 hydrogenation, a base was required, and triethanolamine emerged as the best one. DFT calculations rationalized the mechanism as well as the better performance of triethanolamine as a base.

Dedicated to Professor Irina Petrovna BeletskayaThe catalytic addition of phosphines to alkenes (hydrophosphination) is an attractive process (Scheme 1). [1] It is a 100 % atom-economical reaction that uses widely available and inexpensive starting materials. It offers an access to alkylphosphines, which are useful ligands, [2] organocatalysts, [3] and reagents in organic synthesis. [4] However, due to the high energy of the P À H bond (E = 77 kcal mol À1 ), [5] the reaction usually requires activation by radical initiators. [1c, 6] Thermal-, [7] acid-, [8] and base-promoted [9] reactions have also been applied, although less frequently. Metal-and lanthanide-catalyzed processes were also reported recently. [1c, 10] Whatever the method, the addition usually proceeds in an anti-Markovnikov way leading to the b adduct B (addition of the phosphorus atom to the terminal carbon atom of a terminal alkene). In contrast, the selective formation of the [a] Dr.

Vinylphosphine-borane complexes are easily synthesized by palladium-catalyzed C-P cross-coupling of vinyl triflates with secondary phosphine-boranes. This method allows the synthesis of phosphine derivatives not always easily accessible by other approaches. The vinylphosphine derivatives are purified by chromatography on silica gel. The versatility of the method is proved by using various triflates and diaryl-, dialkyl- and alkylarylphosphine-borane precursors. Chiral enantiopure phosphine-boranes are synthesized from chiral triflates.

A domino desulfitative coupling/acylation/hydration process to synthesize C‐2‐(2‐oxo‐2‐phenylethylidene)‐ and N‐3‐carbonyl‐substituted pyrimidines by unprecedented CC and CN cross‐coupling reactions is described. This methodology couples 3,4‐dihydropyrimidine‐2‐thiones and alkynes under modified Liebeskind–Srogl conditions using palladium acetate and copper(I) carboxylate. Remarkably the copper(I) carboxylates simultaneously act as desulfitative and acylation reagents in the reaction.