Synthesis and Characterization of Phosphinecarboxamide and Phosphinecarbothioamide, and Their Complexation with Palladium(II) Complex

Reactions of isocyanates/isothiocyanates with primary and secondary phosphines without solvent at room temperature afforded phosphinecarboxamide/phosphinecarbothioamide, respectively, in excellent yields. Furthermore, palladium complex Pd(COD)Cl₂ was allowed to react with Ph₂PC(O)NHPh (1a) to afford [Pd{Ph₂PC(O)NHPh-κP}₂Cl₂] (3). On the other hand, the reaction of Pd(COD)Cl₂ with 1 eq. of Ph₂PC(S)NHPh (2a) afforded [PdCl₂{Ph₂PC(S)NHPh-κP,S}] (4). In the case of a 1:2 molar ratio, [PdCl{Ph₂PC(S)NHPh-κP,S}{Ph₂PC(S)NHPh-κP}]Cl (5) was formed. The newly obtained compounds were fully characterized using multielement NMR measurements and elemental analyses. In addition, the molecular structures of Ph₂PC(O)NH(CH₂)₂Cl (1j), Ph₂PC(S)NHPh(4-Cl) (2c), and 3–5 were determined using single-crystal X-ray diffraction.

Novel ferrocenyl functionalised phosphinecarboxamides: synthesis, characterisation and coordination

The synthesis of two novel ferrocenyl-substituted phosphinecarboxamides, FcNHC(O)PH₂ (1; Fc = ferrocenyl) and FcCH₂NHC(O)PH₂ (2), is reported. These two primary phosphines were obtained by the reaction of aminoferrocene with sodium 2-phosphaethynolate in the presence of a proton source or, directly, from aminomethylferrocene hydrochloride and sodium 2-phosphaethynolate. Their ability to act as ligands was probed via reactions of 1 with rhodium(iii) and ruthenium(ii) precursors. The isoelectronic metal complexes [(η⁵-C₅Me₅)RhCl₂(1-κP)] and [(η⁶-mes)RuCl₂(1-κP)] were obtained. Treatment of these compounds with a base resulted in HCl elimination to afford phosphide-bridged dirhodium and diruthenium complexes highlighting that on coordination to a metal, the P-H bonds of these phosphinecarboxamides become increasingly protic.

Synthesis and Structural Characterisation of an N-Phosphanyl Ferrocene Carboxamide and its Ruthenium, Rhodium and Palladium Complexes

[((Diphenylphosphanyl)amino)carbonyl]ferrocene (1) has been synthesized and coordinated to light platinum metals, ruthenium, rhodium and palladium, in diverse coordination modes. Specifically, compound 1 was used to prepare the following phosphane complexes, [(η⁶ -mes)RuCl₂ (1-κP)], [(η⁵ -C₅ Me₅ )RhCl₂ (1-κP)], trans-[PdCl₂ (1-κP)₂ ], and [(L^NC )PdCl(1-κP)] (mes=mesitylene, L^NC =[2-(dimethylamino-κN)methyl]phenyl-κC¹ ). They were subsequently converted into cationic O,P-chelate complexes by halide abstraction with AgClO₄ and into neutral O,P-chelate complexes by deprotonation with potassium tert-butoxide. All coordination compounds and phosphane chalcogenides 1E (P-bound chalcogen atom E=O, S and Se), which were also synthesised, were structurally characterised using spectroscopic methods (IR, multinuclear NMR and ESI MS) and single-crystal X-ray diffraction analysis. The electrochemical behaviour of the prepared compounds was studied by cyclic voltammetry, and the (L^NC )Pd-1 complexes were further studied by Mössbauer spectroscopy.

The phosphinoboration of carbodiimides, isocyanates, isothiocyanates and CO2

The transition metal-free addition of phosphinoboronate ester Ph₂PBpin (pin = 1,2-O₂C₂Me₄) to heterocumulenes including carbodiimides, isocyanates, isothiocyanates and carbon dioxide proceeds with remarkable selectivity to give products in high yield.