Organometallic Lewis Acids,Part LXII. Chiral Carbonyl‐Cyclopentadienyl‐Triphenylphosphine‐Iron and ‐Ruthenium Complexes with Tertiary Nitriles [CpM(CO)(PPh3)(N≡C–CR1R2R3)]+ BF4– (M = Fe,Ru)

A series of tertiary nitriles was synthesized by alkylation of acetonitrile, primary and secondary nitriles, using alkylbromides and sodium amide in liquid ammonia. By reaction of the in situ formed organometallic Lewis acids [CpM(CO)(PPh₃)]⁺ (M = Fe, Ru) with the novel tertiary nitriles, the complexes [CpM(CO)(PPh₃)(N≡C–CR¹R²R³]BF₄ were obtained. A di‐iron complex was formed with 1,6‐dicyanohexane.     

Synthesis,characterization and hydroformylation activity of 7‐azaindolate‐bridged dinuclear rhodium(I)phosphines with pendant polar‐groups

New dinuclear Rh(I)–Phosphines of the types [Rh(µ‐azi)(CO)(L)]₂ ( 1,3 – 7 ) and [Rh(µ‐azi)(L)]₂ ( 8 ) with pendant polar groups, and a chealated mononuclear compound [Rh(azi‐H)(CO)(L)] ( 2 ) (where azi = 7‐azaindolate, L = polar phosphine) were isolated from the reaction of [Rh(µ‐Cl)(CO)₂]₂ with 7‐azaindolate followed by some polar mono‐ and bis‐phosphines ( L ₁ – L ₈ ). A relationship between Δδ³¹P‐NMR and ν(CO) values was considered to define the impact of polar‐groups on σ‐donor properties of the phosphines. These compounds were evaluated as catalyst precursors in the hydroformylation of 1‐hexene and 1‐dodecene both in mono‐ and biphasic aqueous organic systems. While the biphasic hydroformylations (water + toluene) gave exclusively the aldehydes, the monophasic one (aqueous ethanol) showed propensity to form both aldehydes and alcohols. The influence of bimetallic cooperative effects, and σ‐donor and hydrophilic properties of the phosphines with pendant polar‐groups in enhancing the yields and selectivity of hydroformylation products was emphasized. In addition, when strong σ‐donor phosphine was used, the π‐acceptor nature of pyridine ring of 7‐azaindolate spacer was found to be a considerable factor in facilitating the facile cleavage of CO group during hydroformylation and in supplementing the cooperative effects. Copyright © 2009 John Wiley & Sons, Ltd.     

Aminophosphines: their chemistry and role as ligands and synthons

In recent years, research in organophosphorus chemistry has mainly focused in designing newer and better phosphorus ligands for synthesizing novel metal complexes with improved catalytic activities. Aminophosphines [tricoordinate phosphorus(III)–nitrogen systems] are considered as versatile compounds owing to the presence of nitrogen centres which, in principle, can influence additional reactivity features. They are quite sensitive to air and moisture due to the presence of polar P? N bond(s). In spite of this, research in aminophosphine chemistry is gaining momentum day‐by‐day and this is due mainly to one reason: their rich behaviour as ligands in metal complex chemistry and subsequently in catalysis. Their role as synthons in inorganic heterocyclic chemistry has also helped produce new types of heterocycles. In this paper, the chemistry of simple acyclic aminophosphines (synthesis, characterization, reactivity and applications) is covered and particular focus is given to their ability to form chalcogenides along with their role played as ligands in coordination chemistry and as synthons in inorganic heterocyclic chemistry. Copyright © 2009 John Wiley & Sons, Ltd.     

Catalyst- and solvent-free coupling of 2-methyl quinazolinones and 3-(trifluoroacetyl)coumarins: An environmentally benign access of quinazolinone derivatives

An environmentally benign highly atom-economic protocol for the construction of the CC bond has been developed under catalyst- and solvent-free conditions. This protocol involves the efficient coupling of 2-methyl quinazolinones with 3-(trifluoroacetyl)coumarins for the access of quinazolinone derivatives in excellent yields (up to 90 %). The crystal structure of compound 3di was investigated by X-ray diffraction analysis. The biological activities, such as in vitro antifungal activity of the quinazolinone derivatives against Fusarium graminearum, Fusarium moniliforme, Fusarium oxysporum, Phytophthora parasitica var nicotianae, and Rhizoctonia solani Kuhn, were investigated. The bioassay results indicated that most of the target products exhibited promising fungicidal activities, and compound 3 cl exhibited 95 % fungicidal activity against R. solani, with an EC₅₀ value of 10.6 μg/mL.