Tetracoordinated Phosphorus Atom Research Articles

PHOSPHORUS-CONTAINING DERIVATIVES OF INDOLE AND PYRROLE

Data on the synthesis and chemical properties of the phosphorus-containing derivatives of indoles and pyrroles, published in 1976-1998, are reviewed. The introduction of substituents containing tri- and tetracoordinated phosphorus atom into the heterocycle and the side chain is discussed. Information on the biological activity is presented. Authors: P. A. Gurevich and V. A. Yaroshevskaya. English Translation in Chemistry of Heterocyclic Compounds , 2000, 36 (12), pp 1361-1401 http://link.springer.com/article/10.1023/A%3A1017562111215

Reactions of 3-methyl-1,2-butadienylphosphonates with 4,9-dioxa-1,12-dodecanediamine

High reactivity of allene derivatives of the tetracoordinated phosphorus atom in the nucleophilic addition reactions opens a possibility of the effective synthesis on their basis of new β-amino-functionalized organophosphorus compounds. The latter are promising for the use as biologically active compounds, metal extractants, and membrane carriers [1–3]. In this work the results of the study of the reaction between 3-methyl-1,2-butadienylphosphonates I and 4,9-dioxa-1,12-dodecanediamine II are presented. On mixing diamine II with two-fold excess of phosphonate I the oily adduct III was obtained. It was washed with СН2Cl2 to the constant value of nD. In the IR spectra of compound III the stretching vibrations band of allene triad (1955 cm) is absent, and strong bands at 1200 (Р=О), 1590 (С=С), 3300– 3500 cm (NH) appear. The absence of the proton signals of phosphorus methylene group with the spinspin coupling constant JPH 20–22 Hz and of the proton signals of two methyl groups at the double bond makes it possible to ascribe to compounds IIIа and IIIb the enamine structure. Compounds IIIа and IIIb possess effective antimycotic activity.

Pseudo‐Halogen Behavior of Thiophosphoryl Azides as a Tool for the Functionalization of Phosphorus Macrocycles.

Abstract Phosphoryl azides are known as azide-transfer agents in organic chemistry; such behavior denotes the pseudo-halogen character of the azide group when linked to a tetracoordinated phosphorus atom, but it was considered up to now only for the functionalization of organic substrates by N3. We show in this paper that the azide can also be considered as a good leaving group, which facilitates the functionalization of the phosphorus atom which bore it. This reaction is first demonstrated on a small thiophosphoryl azide, then applied to the functionalization of more complex macromolecules, i.e. macrocycles incorporating in their structure thiophosphoryl azido groups.

Pseudo-halogen behavior of thiophosphoryl azides as a tool for the functionalization of phosphorus macrocycles

Phosphoryl azides are known as azide-transfer agents in organic chemistry; such behavior denotes the pseudo-halogen character of the azide group when linked to a tetracoordinated phosphorus atom, but it was considered up to now only for the functionalization of organic substrates by N 3. We show in this paper that the azide can also be considered as a good leaving group, which facilitates the functionalization of the phosphorus atom which bore it. This reaction is first demonstrated on a small thiophosphoryl azide, then applied to the functionalization of more complex macromolecules, i.e. macrocycles incorporating in their structure thiophosphoryl azido groups.

Chiral Configurations of Cyclophosphazenes

Tetracoordinated phosphorus atoms in derivatives of cyclophosphazenes are pentavalent and are potentially chiral. Chirality does not seem to have been investigated nor discussed for any literature examples of crystal structures of those cyclophosphazene compounds which are expected to be chiral. In cyclotriphosphazatriene compounds with ansa-substituted macrocyclic rings the two phosphorus atoms attached to the macrocycle are chiral, although the cis-ansa cyclotriphosphazatriene-macrocycle 1 is the meso form. Reaction of 1 with the di-secondary amine, piperazine, provides a convenient way to investigate the chiral configurational properties of cyclophosphazene compounds. It is found by X-ray crystallography that there are two configurational isomers (one meso and one racemate) of the singly bridged di(cyclophosphazene-macrocyclic) piperazine derivative 6i, and that there are two configurational isomers (both meso) of the doubly bridged di(cyclophosphazene-macrocyclic) piperazine derivative 8i; in 8i one meso form has a center of symmetry and the other a plane of symmetry. The chiral configurational properties of each stage of the reaction scheme for formation of 6i and 8i from 1 have been confirmed by P-31 NMR spectroscopy and the results are consistent with inversion of configuration at phosphorus at each step of the reaction of >P(OR)Cl groups with HNR'R to form >P(OR)(NR'R) derivatives: viz. reaction of 1 with piperazine gives the monosubstituted compound 4i, which exists as a racemate with the macrocyclic ring in the trans-configuration; reaction of compound 4i with 1 gives the two configurational forms (meso and racemate) of the singly bridged derivative 6i with the macrocyclic rings in the trans-trans configuration; reaction of 6i with piperazine gives the monosubstituted singly bridged derivative 7i. which exists as two racemic mixtures with the macrocyclic rings in cis-trans configurations; and intramolecular condensation of 7i gives the two configurational forms of the doubly bridged derivative 8i with each of the macrocyclic rings in the cis-cis configuration. In this work the configurational properties of derivatives of cyclotriphosphazatriene rings with two (one N3P3 unit) or four (two N3P3 units) chiral centers have been rationalized. It is found that the chiral structures of cyclotriphosphazatriene derivatives may be represented by 2D molecular diagrams, as long as the Fischer rules for chiral carbon compounds are followed for phosphorus compounds.

Phosphorus-containing Derivatives of Indole and Pyrrole. (Review)

Data on the synthesis and chemical properties of the phosphorus-containing derivatives of indoles and pyrroles, published in 1976-1998, are reviewed. The introduction of substituents containing tri- and tetracoordinated phosphorus atom into the heterocycle and the side chain is discussed. Information on the biological activity is presented.

Electrooxidation of 2,3-dihydro-1H-1,3,2-diazaphospholes

Electrooxidation of 2-R-1,3-dibutyl-4,5-dimethyl-2,3-dihydro-1H-1,3,2-diazaphospholes with tri- and tetracoordinated phosphorus atoms were studied. Reversible one-electron oxidation gives radical cations at potentials of −0.37 to +0.36 V. Magnetic parameters of the radical cations were measured.

35-Chlorine NQR spectra and molecular structure of solid chlorophosphoric compounds in the series of 1,3,2 λ5-Benzodioxaphosphole

Nuclear quadrupole resonance (NQR) is a high-resolution spectroscopic method of molecular structure determination for solids due to its capability to give signals at specific frequencies for each resonant nucleus in a molecular structure. 35-Chlorine NQR is used here to establish the molecular structure of a number of crystalline chlorine-containing compounds of pentavalent phosphorus and to study their coordination isomerism, which is related to the chlorotropy effect. The 35C1 NQR spectra of solid 4,5-CI2C6H202PCI 3 (I), C6H402PCI2N=CCICCI 3 (II), and C6H402PCI= NCC12CF 3 (HI) (Table 1) were recorded at 77 K on a pulse NQR spectrometer (resonance frequency measurement error v up to _.+5 kHz, nuclear quadrupole spin-lattice relaxation time T 1 about ___10%). The results of measurements in Table i show how 35C1 NQR lines are grouped in the compounds under study. Figure 1 demonstrates the spectrograms of these compounds and compares them with the literature data for "reference" compounds, making it possible to assign the resonance frequencies to molecular fragments in crystals I-III and thus to identify the molecular structure of the corresponding compounds. It is natural to compare the 35-chlorine resonance frequencies of P-CI bonds in sample I with the 35C1 NQR spectrum of the phosphorane C6H402PC13 (spectrumA, Fig. 1). In the latter spectrum, the two high-frequency resonance signals belong to the equatorial chlorines at phosphorus, and the low-frequency signal corresponds to the axial chlorine [1]. The doubled number of 35C1 NQR lines with respect to the number of chlorine atoms in molecule I for both P-CI and C--C1 bonds indicates the presence of two nonequivalent molecular sites in the unit cell of the crystal. The 35C1 NQR lines of P-C1 bonds for the nonequivalent molecules in this double set may be grouped as follows (Table 1): lines 5, 6, and 9 one molecule; lines 7, 8, and 10 the other (according to characteristic ranges of 35-chlorine resonance frequencies for CI e (equatorial) and CI a (axial) and taking into account the splittings and the ratios of the times T 1 in the NQR spectra of the nonequivalent molecules). As to 35C1 NQR lines of C-CI bonds, their assignment to a position in the benzene ring is quite clear, since the 35C1 NQR spectrum of 1,2,4,5-tetrachlorobenzene [2] (spectrum B, Fig. 1) is observed in the same frequency range. Compounds II and III can exist as forms with pentaand tetracoordinated phosphorus atom (chiorotropic tautomerism in the PNC triad):

Tricoordinated phosphorus‐containing macrocycles: New synthetic strategies

AbstractPhosphorus dialdehydes RP (OC6H4CHO)2 (R = Ph, Me2N) react with phosphodihydrazides PhP(Y)‐[N(CH3)NH2]2 (Y = S, O) to give macrocycles 6a–c arising from [2 + 2] cyclocondensation reactions. Treatment of phosphodihydrazone PhP(S) [OC6H4CHN–N(Me)H]2 7 with phenyldichlorophosphine affords macrocycle 8 possessing tri and tetracoordinated phosphorus atoms. Clean desulfurization of thiophosphorus macrocycles 9 and 12 gives rise selectively to new tricoordinated phosphorus containing macrocycles 11 and 13.

Etude de la reactivite du tris(tertiobutyl)phenyldithiophosphorane

Heating of tris(tertiobutyl)phenyldithiophosphorane gives rise to an isomer with a tetracoordinated phosphorus atom. The action of triphenylphosphine loads to a tricyclophosphathiane which can be transformed in diphosphene by an excess of triphenylphosphine. Reactions with various nucleophilic derivatives (pyridine, triethylamine, diethylamine, butylamine, water, tetraphenylarsonium chloride) are described.

Vibrational spectra and conformations of 1,3,2-dioxaphosphepines with exocyclic P-N bond

1. The change in the vibrational (IR, Raman) spectra of nine 2N,N-dialkylamino-5,6-benzo(4,7-dihydro)-1,3,2-dioxaphosphepine during extensive variation of their temperature, aggregate state, and medium indicates the existence of a structure-dependent ability of the molecules to participate in different conformations. 2. Under the above-described experimental conditions, in 5,6-benzo-1,3,2-dioxaphosphepines with a tetracoordinated phosphorus atom and in the 4,7-dihydro derivatives studied, the conformational equilibrium is preferentially shifted in one direction. In the case of 5,6-benzo derivatives of trivalent phosphorus, in a liquid phase an equilibrium is observed of comparable amounts of the two forms of the molecules. 3. The quantitatively dominating, energetically more convenient, and the only remaining in the crystal form in the molecules of 5,6-benzo-1,3,2-phosphepines is the chair conformation with an equatorial P-N bond.

Synthesis and thermal properties of ?-diphospha carbinols

1. The reaction of diphenylphosphine with α-keto phosphonates and α-ketophosphine oxide leads to the formation of α-diphospha carbinols, which have two phosphorus atoms of different valence. 2. Depending on the environment of the phosphorus atoms, the thermal rearrangement of the obtained α-diphospha carbinols goes via either the tri- or tetracoordinated phosphorus atom, which is explained by taking into account the interaction of the phosphorus-containing groupings and the proton of the hydroxyl group.

Study of equilibrium of 5-phenyl-2,4,6-trimethyl-1,3,5-dioxaphosphorinane stereoisomers and their derivatives

We determined the conformational free energy of a phenyl substituent on a tri- and tetracoordinated phosphorus atom in a 2,4,6-trimethyl-1,3,5-dioxaphosphorinane ring.

Steric structure of phosphorus-contaiming heterocycles

The steric structure of 3-halo-1-thia-3-phosphethanes with a tetracoordinated phosphorus atom was investigated by the methods of dipole moments and Kerr constants, enlisting data on quantum chemical calculations of the energies of the conformations.

Three-dimensional structure of phosphorus-containing heterocycles Communication 3. The gauche-orientation of the alkoxy group in 3-alkoxy-1-thia-3-phosphethanes

1. The dipole moments and Kerr constants of five 3-methoxy- and 3-phenoxy-l-thia-3-phosphethanes with a tetracoordinated phosphorus atom were determined. 2. On the basis of a graphical treatment of the data of these methods it was shown that the four-membered ring is bent, and the two-faced angle varies from 140 to 165°. The phosphoryl (or thiophosphoryl) group occupies a pseudoequatorial position; the methoxy and phenoxy radicals have a gaucheorientation.

Mechanism of the hydrolysis of trialkylsilyl esters of oxygen acids of phosphorus

1. The neutral hydrolysis of complete and acid trialkylsilyl esters of phosphorous acid and the acid and neutral hydrolysis of bis(trialkylsilyl)aroylphosphonates were studied. 2. It was shown by the reaction with H218O that in neutral and acid hydrolysis of trialkylsilyl esters of acids of the tri-and tetracoordinated phosphorus atom, there is a predominant cleavage of the Si-O bond in the P-O-Si and P(O)-O-Si groups.

Conjugation with phosphorus atom participation

The UV and Raman spectra of phenyl andβ-styryl derivatives of phosphorus were investigated. The results agree with concepts regarding the insulating effect of tetracoordinated phosphorus atoms and participation in electron effects of the unshared pair of electrons of trivalent phosphorus in the excited state.

Vibrational spectra and structures of a number of oxaazaphospholanes

The Raman and IR spectra of six 1,3,2-oxaazaphospholanes with a tri- and tetracoordinated phosphorus atom were obtained. The bands were assigned, and the spectroscopic features of the oxaazaphospholane ring were noted. Assumptions regarding the peculiarities of the three-dimensional structure of the molecules were made on the basis of the change in the characteristic frequencies on passing from trivalent phosphorus compounds to tetracoordinated phosphorus compounds.

Hückel Molecular Orbital Models for Heterocycles with Tetra-coordinated Phosphorus Atoms

MANY heterocyclic compounds with tetra-coordinated phosphorus atoms have been synthesized1,2. Several models for Hukel molecular orbital calculations3–6 have been proposed for heterocycles containing atoms with d-orbitals, but the most suitable model should first be found before such calculations are made for these phosphorus heterocycles. The most suitable model can be found by comparing the experimental data for phosphabenzene (more exactly 1,1-diphenylphosphabenzene)1,7,8 with the Hukel parameters calculated for all these models.