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The catalytic potential of palladium(II) complexes with chelating N-phosphanyl-N-heterocyclic carbenes featuring a saturated imidazolin-2-ylidene or tetrahydropyrimid-2-ylidene ring has been investigated in intermolecular alkyne hydroamination reactions. The complexes were found to be among the most active Pd-based catalysts for these processes and to enable the use of low reaction temperatures (40 °C) and of solventless conditions. The Pd complexes require activation by 2 equiv of a silver salt to remove chlorido ligands from the metal coordination sphere; they can however also be presynthesized in active form, which allows their use under silver-free conditions. The hydroamination reaction was found to efficiently proceed with terminal alkynes and different ring-substituted, primary arylamine substrates.

The reactions of (di-tert-butylphosphanyl)amines and P,P-di-tert-butylphosphinoselenoic amides with Alder's dimer were studied. For di-tert-butylphosphanylamines, the reaction proceeds by primary electrophilic attack of Alder's dimer at the phosphorus atom to afford a dicationic salt 3. The deprotonation of 3 led to N-phosphanylformamidine 5 (“phosfam”). Alkyl(di-tert-butylphosphanyl)amines reacted with Alder's dimer in a 2:1 molar ratio to give N-phosphanylformamidinium salts; the second equivalent of (alkylamino)phosphane acts as a base. (Arylamino)phosphanes reacted with Alder's dimer to give benzazaphospholium derivatives. To direct the electrophilic attack of Alder's dimer at the nitrogen atom, phosphinoselenoic amides were used. They reacted with Alder's dimer at the selenium atom followed by a selenium–phosphorus shift to give N-(di-tert-butylphosphoroselenoyl)formamidinium salts. The phosphinoselenoic amides with bulky substituents (adamantyl, tBu) underwent cleavage of the N–alkyl bond to afford phosfams. Various key intermediates such as 3 and 22b were isolated and characterized. A convenient method for the synthesis of carbene precursor PIII and PV N-substituted formamidinium salts was developed.

Neutral dinuclear gold(I) complexes having general formula [Au2Cl2(NHCP)] (NHCP = N-phosphanyl N-heterocyclic carbene) have been synthesized by two different synthetic procedures: i) transmetalation of the NHCP ligand from the corresponding dinuclear silver(I) complex; ii) deprotonation of the corresponding N-phosphanyl azolium/tetrahydropyrimidinium salt in the presence of the gold(I) precursor. Interestingly, although the silver complexes are invariably dinuclear dicationic species of formula [Ag2(NHCP)2](OTf)2, both stoichiometries [Au2(NHCP)2](OTf)2 and [Au2Cl2(NHCP)] are potentially accessible with gold. Preference for either stoichiometry is dictated by the steric properties of the NHCP ligand as well as by a proper choice of the experimental conditions. On the other hand, preparation of copper(I) compounds with [Cu2Cl2(NHCP)] stoichiometry leads to product mixtures and has not led up to now to pure neutral compounds. Both the silver(I) and gold(I) complexes have been structurally characterized.

A direct synthetic approach to C-phosphanyl-N,N-dialkyl-N′-aryl(alkyl)-formamidines was developed. It was shown that phosphorylation of the formamidines proceeds at the nitrogen atom affording N-phosphanylformamidinium salts. Upon deprotonation, these salts gave C-phosphanylformamidines via formation of carbenes followed by a 1,2-phosphorus shift.

A direct synthetic approach to C-phosphanyl-N,N-dialkyl-N′-aryl(alkyl)-formamidines was developed. It was shown that phosphorylation of the formamidines proceeds at the nitrogen atom affording N-phosphanylformamidinium salts. Upon deprotonation, these salts gave C-phosphanylformamidines via formation of carbenes followed by a 1,2-phosphorus shift.

The authors have established that hexaalkyltriamidophosphazo groups are unusually strong electron-donor substituents at P /SUP III/ , causing the extremely high basicity of such compounds. This paper performs methylation of tris (tris (N,N-dimethylamido) phosphazo) phosphate and tris (tris (N,N-dimethylamido) phosphazo) methoxyphosphonium iodide (I) using methyl oxide. The NMR spectra were recorded on a Bruker WP-20 spectrometer, and hexamethyldisiloxane and 85% H/sub 3/PO/sub 4/ were used as the standard.