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Dichlorophosphoranides featuring N,N-dimethyl-N′-arylformamidine substituents were isolated as individual compounds. Dichlorophosphoranide 9 was prepared by the multicomponent reaction of C-trimethylsilyl-N,N-dimethyl-N′-phenylformamidine and N,N-dimethyl-N′-phenylformamidine with phosphorus trichloride. Its molecular structure derived from a single-crystal X-ray diffraction was compared to the analogous dibromophosphoranide prepared previously by us by the reaction of phosphorus tribromide with N,N-dimethyl-N′-phenylformamidine. It was shown that a chlorophosphine featuring two N,N-dimethyl-N′-mesitylformamidine substituents reacted with hydrogen chloride to form dichlorophosphoranide 11. Its molecular structure was also determined by X-ray analysis and compared with that of closely related dichlorophosphoranide C.

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.

Phosphorylation of N-trimethylsilyl- and N-dimethyl-tert-butylsilylpyrroles with phosphorus tribromide in pyridine proceeds selectively at position 3 of the pyrrole ring. Removal of the trialkylsilyl protecting group has furnished the first representatives of N-unsubstituted 3-phosphorylated pyrroles. © 2008 Wiley Periodicals, Inc. Heteroatom Chem 19:93–96, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/hc.20416

The investigation concerns the effect of a bulky substituent at the pyrrole nitrogen atom on the orientation and regioselectivity of pyrrole phosphorylation with phosphorus(III) halides. As shown, phosphorylation of N-iso-propylpyrrole with phosphorus tribromide or trichloride proceeds nonregioselectively at positions 2 and 3 but it is followed by the 2 3 migration of the dihalogenophosphine group which quantitatively yields the 3-isomer. N-tert-butylpyrrole is regioselectively phosphorylated with halogenophosphines at position 3. The tert-butyl substituent at the nitrogen atom does not preclude the binding of even two or three pyrrolyl residues to the phosphorus atom. The key compounds, 3-pyrrolyldihalogenophosphines, were isolated in a pure state, characterized and used to obtain a number of stable phosphorus(V) derivatives. © 2005 Wiley Periodicals, Inc. Heteroatom Chem 16:599–604, 2005; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/hc.20158

A further member of 2,4,6-trialkyl-phenyl-phos-pholes, the ditertbutylmethylphenyl derivative (1c) was characterized by Bird index and by the sum of angles at the phosphorus atom to describe the flattening of the P-pyramid. Both numbers suggested a slight aromaticity. The reaction of arylphospholes with phosphorus tribromide was extended to phosphole 1c leading this occasion, after further steps, to the mixture of 3- and 2-substituted products (3c-1 and 3c-2, respectively). A triisopropylphenyl-2H-phosphole (4) formed by sigmatropic rearrangement was utilized in the preparation of new 1-phosphanorbornene derivatives, such as sulfide 6 and hemi-oxides 8-1 and 8-2. Further oxidation of the latter species (8-1 and 8-2) led to the decomposition of the dimeric structure (11). 4 could also be trapped by benzaldehyde to afford the oxaphosphanorbornene (10) as one diastereomer. Finally, the reversible formation of 2H-phosphole 4 from 1H-phosphole 1a at 150°C was proved. © 2005 Wiley Periodicals, Inc. Heteroatom Chem 16:104–222, 2005; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/hc.20077

Novel 3 substituted 1,5-dihydro-2,4,3-benzodioxaphosphepine 3-oxides (5a–h) were synthesized by reacting 1,2-benzenedimethanol (1) with phosphorus tribromide in the presence of triethylamine at 0–30°C and subsequent reaction of the monobromide (2) with different Grignard reagents (3) at room temperature. The products (4) were converted to corresponding oxides 5a–i by oxidation with H2O2 at room temperature. The chemical structures of all the products were confirmed by analytical, IR and NMR (1H, 13C, and 31P) spectral data. Their antifungal and antibacterial activity is also evaluated. Most of these compounds exhibited moderate antimicrobial activity in the assay. © 2005 Wiley Periodicals, Inc. Heteroatom Chem 16:572–575, 2005; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/hc.20154

Phosphorylation of N-arylpyrroles with phosphorus tribromide proceeds regioselectively at the position 2 of the heterocyclic system. A 2-to-3 migration of the dibromophosphino group has been discovered, with its ease depending on the electronic nature of a substituent on the phenyl ring, solvent polarity, and the presence of pyridine hydrobromide in the reaction mixture. Further phosphorylation of 2- and 3-monophosphorylated N-arylpyrroles regioselectively involves the respective positions 4 and 5 of the heterocycle and is governed by the electron-acceptor effect of the phosphorus-containing substituent. © 2002 Wiley Periodicals, Inc. Heteroatom Chem 13:223–228, 2002; Published online in Wiley Interscience (www.interscience.wiley.com). DOI 10.1002/hc.10012

A reaction of phosphorus tribromide with a compound containing two 2,5-dimethyl-1-arylpyrrolyl-3 residues bound through a phosphorus atom gave rise to a new phosphorus-containing heterocyclic system, 1,4-diphosphinine. The new products thus obtained have been characterized and described. © 2002 John Wiley & Sons, Inc. Heteroatom Chem 13:46–52, 2002; DOI 10.1002/hc.1105

This study covers phosphorylation of heterocyclic analogues of N-methyldiphenylamine with phosphorus tribromide in pyridine solution. The reaction is found to proceed regioselectively in accordance with the orienting effect of the amino group. Mono and bis-phosphorylated derivatives of the heterocycles have been isolated and characterized. It is pointed out that the heterocyclic systems under study exhibit reduced reactivity in electrophilic phosphorylation as compared to N-methyldiphenylamine. The results of calculations by the PM3 method are reported for the starting molecules and their σ-complexes. © 2001 John Wiley & Sons, Inc. Heteroatom Chem 12:652–657, 2001

Phosphorus trichloride in a basic medium is a convenient reagent for the direct C-phosphorylation of electron-rich aromatic heterocycles. The compounds obtained can be used for the synthesis of various types of heteroaryl and diheteroaryl derivatives of tri- and pentavalent phosphorus. © 1995 John Wiley & Sons, Inc.