Facile synthesis of C-phosphanylformamidines via a carbene pathway

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.     

Peculiarities of resonant interaction in paired impurity centers of 2-fluoronaphthalene in naphthalene

Abstract

Fluorescence and absorption spectra of the 2-fluoronaphthalene admixtures in naphthalene were studied at low temperature (T?=?4.2 К). Two types of pairwise impurity centers were formed at admixture concentrations of more than 1?wt%. Polarization of absorption bands was detected; these spectra were determined by resonance interactions between molecules of the impurity center. Resonant splitting of electronic levels for the translationally nonequivalent molecules in the unit cell of the naphthalene crystal was analyzed for the case, when one molecule was in the similar phase with the incident light wave and the other one was in antiphase.     

A representative of p,p,p-trihalogenylides: synthesis and structure

The representative of P,P,P-trichloroylides-5-methyl-2-phenyl-4-(trichlorophosphoranylidene)-2,4-dihydro-3H-pyrazol-3-one-was synthesized. Its constitution was confirmed by 1H, 13C, and 31P NMR spectroscopy and by X-ray analysis. Some chemical properties were studied and compared with ones of P,P,P-trimethylylide-5-methyl-2-phenyl-4-(trimethylphosphoranylidene)-2,4-dihydro-3H-pyrazol-3-one. DFT calculations of the model molecules were carried out.     

Zwitterionic Phosphoranides as Intermediates in the Reaction of Phosphorus Tribromide with N,N‐Dimethyl‐N′‐arylformamidines

Cyclic zwitterionic phosphoranides 2a,b were found to be intermediate products in the reaction of N,N‐dimethyl‐N′‐(aryl)formamidines with PBr₃. The structure of phosphoranide 2a was determined by means of the X‐ray and quantum chemistry investigations. Mechanism of its formation was proposed based on Density functional theory (DFT) calculations. Reactions of 2 with amines and selenium yielded either C‐phosphorylated formamidines or benzazaphospholes. The first example of intramolecular heterocyclization of a pentavalent phosphorus derivative 15b into 3Н‐1,3‐benzazaphosphole has been demonstrated.