MIXED ANHYDRIDES OF DIALKYLPHOSPHINOUS ACIDS AND DIALKYL HYDROGEN PHOSPHITES,AND THE ISOMERIC MONOXIDES

Abstract

The three isomers possible for oxidized 1,1-dialkyl-2,2-dialkoxydiphosphines, R₂(O)P–P(OR')₂ 1, R₂P–O–P(OR')₂ 2, and R₂P–P(O)(OR')₂ 3, have been synthesized. Irreversible transformations of 1 to 2 and 2 to 3 have been found and the rearrangement patterns, the role of electrophilic and nucleophilic catalysts are discussed. The fact that 3 is more stable than 1 is attributed to higher donor activity of the ligands attached to the four-coordinate phosphorus in 3. Acid chlorides have been shown to attack the phosphorus atom of ambident anions of trivalent phosphorus acids (the products are 1 and 3) whereas the acids proper react with the acid halides at the oxygen atom, to give 2.     

REACTIONS OF A PHOSPHORANIMINE ANION WITH SOME ORGANIC ELECTROPHILES

Abstract

The reactions of a variety of electrophiles with the N-silyl-P-trifluoroethoxyphosphoranimine anion Me₃Sin°P(Me)(OCH₂CF₃)CH^? ₂ (1a), prepared by the deprotonation of the dimethyl precursor Me₃SiN[dbnd]P(OCH₂CF₃)Me₂ (1) with n-BuLi in Et₂O at-78°C, were studied. Thus, treatment of 1a with alkyl halides, ethyl chloroformate, or bromine afforded the new N-silylphosphoranimine derivatives Me₃SiN[dbnd]P(Me)(OCH₂CF₃)CH₂R [2: R = Me, 3: R = CH₂Ph, 4: R = CH[sbnd]CH₂, 5: R = C(O)OEt, and 6: R = Br]. In another series, when 1a was allowed to react with various carbonyl compounds, 1,2-addition of the anion to the carbonyl group was observed. Quenching with Me₃SiCl gave the O-silylated products Me₃SiN[dbnd]P(Me)(OCH₂CF₃)CH₂°C(OSiMe₃)R¹R² [7: R ¹ = R ² = Me; 8: R ¹ = Me, R ² = Ph; 9: R¹ = Me, R ² = CH[sbnd]CH₂; and 10: R ¹ = H, R ² = Ph]. Compounds 2–10 were obtained as distillable, thermally stable liquids and were characterized by NMR spectroscopy (¹H, ¹³C, and ³¹P) and elemental analysis.     

SYNTHESIS AND PROPERTIES OF THE FIRST DISULFUR AND DISELENIUM COMPLEXES OF PLATINUM

The reactions of overcrowded platinum(0) complexes [Pt{P(Ar)Me₂}₂] (Ar = 2,4,6-tris[bis(trimethylsilyl)methyl]phenyl (Tbt), 2,6-bis[bis- (trimethylsilyl)methyl]-4-[tris(trimethylsilyl)methyl]phenyl (Bbt)) with elemental sulfur and selenium resulted in the formation of the first platinum disulfur and diselenium complexes, [Pt(S₂){P(Ar)Me₂}₂] (4a (Ar = Tbt), 4b (Ar = Bbt) and [Pt(Se₂){P(Ar)Me₂}₂] (5a (Ar = Tbt), 5b (Ar = Bbt)) respectively. The x-ray crystallographic analyses of 4b and 5b showed a novel three-membered PtE₂ (E = S, Se) ring structure with a square planar geometry around the platinum center. The oxidation of 4b and 5b with an equimolar amount of m-chloroperbenzoic acid or tert-butyl hydroperoxide in dichloromethane yielded the corresponding disulfur and diselenium monoxide complexes [Pt(E₂O){P(Bbt)Me₂}₂] (6 (E = S), 7 (E = Se)). The further reactions of 6 and 7 with an excess of oxidants gave the corresponding O,S-coordinated thiosulfato complex [Pt(S₂ O₃){P(Bbt)Me₂}₂] (8) and the O,O-coordinated selenito complex [Pt(SeO₃){P(Bbt)Me₂}₂] (11), respectively. The dynamic behavior in solution was revealed by the variable-temperature NMR spectroscopy for 4b, 5b, 8, and 11, which indicates the existence of the intramolecular CH···E (E = O, S, Se) interactions between the methine hydrogens of the o-bis(trimethylsilyl)methyl groups and the Pt-bonded chalcogen atoms.     

STEREOCHEMISTRY OF (R)-2-METHYLAZIRIDINE COMPLEXES OF COBALT(III) AND DIMERIZATION OF THE LIGAND

Abstract

A cobalt(III) complex containing (R)-2-methylaziridine (R-meaz), [Co(R-meaz)(NH₃)₅]³⁺, was prepared and the two diastereomers arising from the presence of the chiral nitrogen atom (N(R) and N(S)) were separated by column chromatography. Molecular mechanics calculations estimated the N(R)-isomer to be more stable. This result was supported by the x-ray structure determination of the more abundant (ca. 94%) isomer, N(R)-[Co(R-meaz)(NH₃)₅]Br₃H₂O. Crystal data: monoclinic, P2₁, a = 7.357(1), b = 9.780(1), c = 10.426(1) Å, μ = 93.58(1)°, V= 748.7(3) ų, Z= 2. Kinetic studies of isomerization (epimerization) between the two isomers revealed that inversion at the nitrogen center was very slow (5 × 10^?2 M^?1 S^?1at 25 °C). The small rate constant seems to be related to the strained three-membered structure of the meaz ligand. The reaction of Na₃[Co(N0₂)6] and R-meaz yielded a complex containing two dimerized R-meaz chelates, trans-[Co(NO₂)2(di-R-meaz)₂] (di-R-meaz =RR)-α,2-dimethyl-l-aziridineethanamine). The crystal strucrure of trans-[Co(NO₂)₂ (di-R-meaz)₂]C1O₄H₂O was established by x-ray crystallography. Crystal data: orthorhombic, P2₁2₁2₁, a = 11.784(6), b = 21.023(9), c = 8.608(7) Å, V = 2133(2) ų, Z = 4.     

STRUCTURES AND PROPERTIES OF COPPER(II) COMPLEXES WITH IMINODIACETATO AND IMIDAZOLE OR RELATED LIGANDS. I. CRYSTAL STRUCTURE OF AQUA(IMIDAZOLE) (IMINODIACETATO)COPPER(II) MONOHYDRATE AND (IMIDAZOLE)(N-CARBOXYMETHYL-D,L-THREONINATO)COPPER(II)

Abstract

The crystal structures of two mixed-ligand copper(II) complexes having iminodiacetate(2-) (IDA) or N-carboxymethyl-D,L-threoninato(2-) ion (CMT) as terdentate ligands and imidazole (ImH) as an N-heterocyclic ligand are reported. Both compounds crystallize in the orthorhombic system, space group Pbca with Z = 8. Aqua(imidazole)(iminodiacetato)copper(II) monohydrate (I,R = 0.065, R _w = 0.075) consists of H₂O molecules and [Cu(IDA)(ImH)(H₂O)] complex units in a hydrogen bonding network. The structure of imidazole(N-carboxymethyl)-D,L-threoninatocopper(II) (IV, R = 0.066, Rω 0.078) is built up of hydrogen bonded polynuclear chains. In both compounds the Cu(II) ion exhibits a flattened and distorted square-based pyramidal coordination, with a terdentate aminoacidate ion, IDA or CMT, and one ImH ligand at the base and H₂O (in I) or the oxygen atom of the OH side chain from one adjacent CMT ion (in IV) as the fifth apical ligand. The nearly coplanar conformation of the two five-membered chelate rings in I and IV is discussed in connection with the known structure of corresponding aquacomplexes (with H₂O instead of ImH) and the ability of terdentate aminoacids to give ternary Cu(II) complexes having two N-heterocyclic donors (2 ImH or one 2,2′-bipy) per Cu(II) atom.     

N-PHOSPHORYL AMINO ACIDS AND PEPTIDES: PART I. THE CRYSTAL AND MOLECULAR STRUCTURE OF N-(O,O-DIISOPROPYL PHOSPHORYL)-TRANS-4-HYDROXY-D,L-PROLINE

Abstract

The crystal and molecular structure of N-(O,O-diisopropyl phosphoryl)-trans-4-hydroxy-D,L-proline has been determined by X-ray diffraction analysis and is compared with proline or hydroxyproline residue in a peptide chain described in the literature. The compound crystallized in orthorhombic system with space group P2₁2₁2₁, a=6.934(2), b=8.694(3), c=26.727(7) Å, V=1611.3(8) ų, Z=4, Dx=1.22 g/cm³. The structure was solved by direct method and refined by anisotropic least squares to a discrepancy index R=0.072. In the compound, the nitrogen atom is trigonal and its remaining 2p orbital is conjugated with the P?Oπ system; the conformation of the phosphorimidate function is favoured by the trans orientation of the P=O bond with respect to the N-C4 bond. In the pyrrolidine ring moeity, the C2-C1-N-C4 atoms are nearly copolnar and the C3 atom is out of the plane by about 0.47 Å.     

X-RAY STRUCTURES OF BIS[(2-AMINOPHENYL)DIPHENYLPHOSPHINE]BIS-(ETHANOL)SILVER(I) NITRATE AND TRIS[(2-AMINOPHENYL)DIPHENYLPHOSPHINE] SILVER(I) NITRATE MONOHYDRATE

Abstract

The crystal structures of two Ag(I) salts, [Ag(LH)₂(EtOH)₂](NO₃) (1) and [Ag(LH)₃](NO₃).H₂O (2) where LH is (2-aminophenyl)diphenylphosphine, have been determined at room temperature. In 1 the Ag atom is coordinated by two P atoms derived from the phosphine ligands (Ag-P(1) 2.433(3) and Ag-P(2) 2.439(3) Å and P(1)-Ag-P(2) 160.1(1)°) and two O atoms derived from two weakly coordinating ethanol molecules (Ag-O(1a) 2.49(1) and Ag-O(2a) 2.75(1) Å). In 2 the three phosphine ligands coordinate via the P atoms (Ag-P 2.455(2), 2.462(2) and 2.484(2) Å) which define a trigonal planar geometry about the Ag atom. In neither case was any evidence found for a bonding interaction between the amino-N atom and the Ag atom. Crystals of 1 are monoclinic, space group P2₁/n with unit cell dimensions: a=10.272(4), b=16.358(2), c=23.709(3) Å, β=101.01(2)° and Z=4 and crystals of 2 are triclinic, space group P 1 with a=11.857(2), b=21.285(2), c=11.190(4) Å, α=91.77(1), β=104.50(2), γ=97.93(1)° and Z=2. The structures were each refined by a full-matrix least-squares procedure to final R=0.058 using 2433 reflections for 1 and to R=0.069 using 4428 reflections for 2.     

VIBRATIONAL SPECTRA AND STRUCTURE OF ALKOXY AND CHLOROALKOXY DERIVATIVES OF ANTIMONY(V)

Abstract

Vibrational spectra of (CH₃O) _n SbCl_5–n . n = 1: 1; n = 2: 2: n = 3: 3: n = 4: 4; n = 5: 5; have been recorded. According to ir and Raman data 1–5 are centrosymmetrical bridged dimers. The Raman spectra of 3–5 exhibit v(Sb–O) doublets of terminal CH₃O at 530–541 and 550–570 cm^?1; vibrations of the 4-membered Sb₂O₂ ring, observed in the 500–517 cm^?1 region of the ir spectra of 1–5, are absent. The v(C–O) bands of bridged and terminal CH₃O are shifted to higher wave numbers (60 and 31 cm^?1, respectively) in the series 1 → 5. The stability of the dimers increases in the series 1 < 2 < 3 < 4 ? 5. At 100–120°C and in CH₃CN solutions dimers of 1–3 dissociate to monomers (v(Sb–O) 537–540 cm^?1, ir data). The monochloride, 4, is partially dissociated in CH₃CN. On solution of the tetrachloride, 1, in benzene a dimer-monomer equilibrium has been observed, with the dimeric form being predominant.     

Polarity and Conformatios of Phosphorylethylenes and Phosphorylacetates in Solution

Abstract

A series of derivatives R¹R²P(X)R³, where R¹=R²=Ph. R³= -CH=CH-Me, X=O(I); R¹=Me, R²=Ph, R³= -CH=CH₂, X=O(II); R¹=R²=Ph, R³= -CH=CH₂, X=Se(III) and R¹R²P(O)-CH₂C(O)OX, where R¹=Ph, R²= -CH=CH₂, X=Ment?(IV); R¹=Ph-2-OMe, R²=Ph, X=Ment?(V); R¹=R²=CH₂Ph, X=Et(I), were investigated by means of dipole moments method. The problem of conjugation in phosphorylethylenes and conformation behaviour of phosphorylacetates was considered. DM (exp.) of (I-IV), determined in CC1₄ solution are 4.48(I), 4.27(II), 4.97(III), 4.21(IV), 5.21(V) and 4.02 D (VI). The intramolecular electronic interactions of phosphoryl group with unsaturated fragment did not displays in polarity properties of compounds (I-III). The experimental dipole moments of derivatives (I-III) are equal to the calculated values of DM. DM (IV-VI) is very sensitive to orientation of the P=O and C=O polar bonds. Because DM (exp.) of these compounds very sensitive to its orientation. DM (calc.) for cis- and trans- orientation of P=O and C=O dipoles are really different, that allows to drow the conclution that, in the contrast to the crystal state, the corresponded dipoles prefer an anti array in solution.     

Tin Tetrachloride Adducts with Arylphosphoramidates: A Multinuclear (31P, 19F,and 119Sn) NMR Characterization in Solution

Abstract

The synthesis of octahedral complexes [SnCl₄L₂] (L = R₂NP(O)(OCH₂CF₃)(O-p-tolyl): R₂N = Me₂N (1), Et₂N (2), CH₂(CH₂CH₂)₂N (3), and O(CH₂CH₂)₂N (4), or L = R₂NP(O)(OCH₂CF₃)(O-p-PhNO₂): R₂N = Me₂N (5), Et₂N (6), and O(CH₂CH₂)₂N (7) is described. The new adducts have been characterized by multinuclear (³¹P, ¹⁹F, ¹¹⁹Sn) NMR, IR spectroscopy, and elemental analyses. The solution NMR data show the presence of a mixture of cis and trans isomers. The structure of the complexes in solution was further confirmed by ¹¹⁹Sn NMR spectra, which display a triplet for each isomer, indicating an octahedrally coordinated tin center. The effects of the nature of R and Ar substituents on the donor ability of the P=O group in the ligands R₂NP(O)(OCH₂CF₃)(OAr) were investigated on the basis of ¹¹⁹Sn NMR chemical shifts and used to classify these ligands according to their Lewis basicity.     

DER OXIDATIVE ABBAU VON THIOPHOSPHIN- THIOPHOSPHON- UND THIOPHOSPHORSÄUREESTERN MIT HYPOCHLORIT

Abstract

The thioesters R¹R²P(X)SR (X=O,S) 1 to 4 are degradated oxidatively forming R¹R²P(O)OH and R-SO³H. The influence of the following parameters on the oxidation course is investigated using standard conditions: pH, concentration of the hypochlorite, quality of the organic phase and cooperation of phase transfer catalysts and hypochlorite cations.

The thioesters 1 to 4 are degradated by hypochlorite with different rates depending on the type of the ligands R¹ and R² and the employment of an optimal pH. An analytical evaluation is possible.

Die Thioester R¹R²P(X)SR (X=O,S) 1 bis 4 werden durch Hypochlorit oxidativ zu R¹R²P(O)OH und RSO₃H abgebaut. Der Einfluß folgender Parameter auf den Oxidationsverlauf unter Standardbedingungen wird untersucht: pH, Hypochloritkonzentration, Art der organischen Phase, Mitwirkung von Phasentransfer-Katalysatoren und der Hypochlorit Kationen.

Die Thioester 1 bis 4 werden mit Hypochlorit in Abhängigkeit vom Typ der Liganden R¹ und R² und nach Einstellen eines optimalen pH-Wertes unterschiedlich schnell abgebaut. Dieser Unterschied ist analytisch auswertbar.     

SYNTHESIS AND NMR SPECTROSCOPIC INVESTIGATION OF PHENYLPHOSPHORYL DERIVATIVES

Abstract

The syntheses of 16 phenyl- (1 and 3) and phenylthiophosphoryl (2) derivatives are described. The ¹³C and ¹⁷O NMR data sensitively reflect electron density changes in the phosphoryl substituents caused by p^π–d^π back-donation from X/Y to P. Taft constants σ₁ and σ_R ⁰ were derived for 16 phosphoryl substituents.     

STRUCTURES OF PYRIDINE CARBOXYLATE COMPLEXES OF COBALT(II) AND COPPER(II)

Abstract

The syntheses and crystal structures of [Co(nic)₂(H₂O)₄] (1). [Co(iso)₂(H₂O)₄] (2). [Cu(nic)₂(H₂O)₄] (3), and [Cu(iso)₂(H₂O)₄] (4) (nic = nicotinate; iso = isonicotinate) are reported. Complex 1 crystallizes in monoclinic, space group C2/m with cell parameters a =14.150(4). b = 6.883(2)., c = 8.497(2) Å, β= 118.28(2)° and Z = 2. The other crystals. 2. 3. and 4. are all triclinic, Pī; a = 9.777(3), b = 6.348(4), c = 6.888(3)Å, a= 113.10(6)., β= 110.55(3). γ = 97.61(5)°, and Z=l for 2; a = 7.0281(4), b = 7.7176(6), c = 8.6978(7)Å, a = 68.103(7), β = 68.526(5), γ = 62.550(6)°, and Z=1 for 3; a = 9.1807(4), b = 6.3334(3), c = 6.8871(3)Å, a= 108.213(4), β = 99.433(4), γ= 105.190(4)°, and Z= 1 for 4. The arrangements around the metal ions are trans-octahedra with two pyridyl nitrogens and two aqua oxygens in the equatorial positions and two aqua oxygens in the axial positions, although the Cu(II) complexes show a larger Jahn-Teller distortion.     

SYNTHESIS OF THE FIRST BENZODISELENAGERMOLES AND ONE SPIROBISDISELENAGERMOLE

Abstract

The first examples of compounds R¹R²GeSe₂C₆H₄R³ (R¹,R²=CH³ C₂H₅, C₃H₂, n-C₄H₉, i-C₅H₁₁, Ph, p-CH₃Ph. R³=H, CH₃, OCH₃) were easily obtained (40–80% yield) from electrophilic cleavage of diselenophenylene zirconocenes by dialkyl or diaryl dichlorogermanes. The synthesis of a spirodi-selenagermole was achieved in the same way using germanium tetrachloride. Analytical data, ¹H and ⁷⁷Se NMR. mass spectra are perfectly consistent with the expected structures.     

PHOSPHORYL TO CARBONYL MIGRATION OF AMINO GROUPS IN MIXED ANHYDRIDES. REACTIVITY AND CRYSTAL STRUCTURE OF N-METHYL-2-BENZOYLOXY-2-OXO-1,3,2-OXAZAPHOSPHORINANE

Abstract

Cyclic mixed anhydride, N-methyl-2-benzoyloxy-2-oxo-1,3,2-oxazaphosphorinane (1a) has been synthesised and the rate of its fragmentation involving nitrogen migration from phosphorus to carbonyl carbon has been measured. (1a) was found to be ca. 60 times less reactive than the non-cyclic, O-methyl-N,N-dimethyl analogue. The crystal and molecular structure of (1a) has been determined using x-ray diffraction. Pna2₁, a=22.229(6), b=7.597(2), c=7.210(2) Å; V=1217.6(6) ų. Final R=3.08% for 1037 reflections with I(rel) > 2[sgrave]I(rel) and 157 parameters. The observed conformation of the molecule of (1a) is very different from that required for the fragmentation to occur; in order to achieve the geometry postulated for the transition state significant rotations about the P[sbnd]O and O[sbnd]C bonds would be necessary and steric hindrance by the 4,6-axial hydrogens would be expected.     

CRYSTAL STRUCTURE OF THE ISOMORPHOUS COMPLEXES TETRAAQUABIS(2,6-DIHYDROXY-BENZOATO-O)(2,6-DIHYDROXY-BENZOATO-O,O)TERBIUM(III) AND HOLMIUM(III) DIHYDRATE

Abstract

The structures of isomorphic Tb(III) and Ho(III) complexes with 2,6-dihydroxybenzoic acid of formula [Tb(C₇H₅O₄] 2H₂O and [Ho(C₇H₅O₄)₃ 4H₂O] 2H₂O has been determined by X-ray diffraction and refined to a residual R = 0.030 for 5376 observed reflections and R = 0.0284 for 5660 observed reflections, for Tb(III) and Ho(III) complexes, respectively. Crystals are triclinic, space group P1 with a= 10.748(2), b=11.309(2), c = 12.452(2)Å, α = 82.28(3), ? = 73.05(5), γ = 68.27(3)° for Tb(III) and a= 10.731(2), b=11.269(2), c = 12.436(2)Å, α = 82.25(3), β = 72.92(3), γ = 68.46(3)° for Ho(III).

In the structure of these monomelic complexes the metal ions are coordinated by oxygen atoms of one bidentate chelating and two monodentate carboxylate groups and four molecules of water. Tb-O distances are in the range 2.323(3)-2.506(3) Å and Ho-0 2.297(3)-2.486(3) Å. The crystal structure, consisting of discrete units of neutral complexes with two molecules of water of crystallization is stabilized by intra-and intermolecular hydrogen bonds.     

Fluorinated phosphorus compounds: Part 6. The synthesis of bis(fluoroalkyl) phosphites and bis(fluoroalkyl) phosphorohalidates

Reaction of phosphorus trichloride with tert-butanol and fluoroalcohols gave bis(fluoroalkyl) phosphites (R_FO)₂P(O)H in 42-89% yield, where R_F=HCF₂CH₂, H(CF₂)₂CH₂, H(CF₂)₄CH₂, CF₃CH₂, C₂F₅CH₂, C₃F₇CH₂, (CF₃)₂CH, (FCH₂)₂CH, CF₃(CH₃)₂C, (CF₃)₂CH₃C, CF₃CH₂CH₂, C₄F₉CH₂CH₂ and C₆F₁₃CH₂CH₂. Treatment of these with chlorine in dichloromethane gave the bis(fluoroalkyl) phosphorochloridates (R_FO)₂P(O)Cl in 49-96% yield. The chloridate (CF₃CH₂O)₂P(O)Cl was isolated in much lower yield from the interaction of thionyl chloride with bis(trifluoroethyl) phosphite. Heating the latter in dichloromethane with potassium fluoride and a catalytic amount of trifluoroacetic acid gave the corresponding fluoridate (CF₃CH₂O)₂P(O)F in 84% yield. Treatment of bis(trifluoroethyl) phosphite with bromine or iodine gave the bromidate (CF₃CH₂O)₂P(O)Br and iodidate (CF₃CH₂O)₂P(O)I in 51 and 46% yield, respectively. The iodidate is the first dialkyl phosphoroiodidate to have been isolated and characterised properly—its discovery lags behind the first isolation of a dialkyl phosphorochloridate by over 130 years. The fluoroalkyl phosphoryl compounds are generally more stable than known unfluorinated counterparts.     

SYNTHESIS,CHARACTERIZATION AND CRYSTAL STRUCTURE OF A COMPLEX OF EUROPIUM PERCHLORATE WITH METHYLENE BIS(DIPHENYLPHOSPHINE OXIDE)

Abstract

A complex of europium perchlorate with methylene bis(diphenylphosphine oxide) (HMPPO), [Eu(HMPPO)₄](ClO₄)₃·2H₂O has been synthesized and characterized by X-ray crystallography, infrared spectroscopy and thermal analysis. The X-ray structure of the complex shows Eu(III) is coordinated by eight oxygen atoms from four HMPPO ligands, forming a distorted square antiprism coordination geometry. The complex crystallizes in space group P-1 with cell parameters a = 15.807(3), b = 17.868(4), c = 20.656(4) Å, α = 86.85(3)°, β = 82.33(3)°, γ = 66.75(3)°. The final R_l and R_w are 0.0803 and 0.1994, respectively, for 9540 observed reflections [I > 2[sgrave](I)]. Its luminescent properties have also been studied.     

PREPARATION AND REACTIONS OF METHYLTHIOMETHYL-SUBSTITUTED PHOSPHORUS HALIDES1

Abstract

Methylthiomethylphosphonous dichloride, MeSCH₂PCI₂ (1), is synthezised by the reaction of MeSCH₂SnBuⁿ, with phosphorus trichloride. Substitution reactions to give MeSCH₂PX₂ (X=NEt₂, OPrⁱ, F, Ph) are described. The phosphorus(III) compounds are readily converted to the corresponding phosphonyl and thiophosphonyl derivatives, MeSCH₂P(Z)X₂ (Z=O, S), and the phosphorane, MeSCH₂PF₄, respectively. Chlorination of the methylene group to give compounds of the type MeSCHCIP(O)X₂ and MeSCCI₂P(O)X₂ is reported.     

Reaction of Quinoline-5,8-Diones with Selected Charged Phosphorus Nucleophiles

Abstract

The redox reactivity of the two quinoline-5,8-dione derivatives—2-methyl-5,8-dioxo-5,8-dihydroquinoline-7-amine (2a) and N-(2-methyl-5,8-dioxo-5,8-dihydroquinolin-7-yl)acet-amide (2b)—has been demonstrated by their reaction with negatively charged three-coordinated phosphorus nucleophiles, such as R₂P-YM (1a–d, Y = O or lone pair; R = Ph, tBu, OCH₂CMe₂CH₂O, or EtO; M = Li or Na). 1a–d participated in single-electron transfer (SET) to 2a and 2b, generating the radical anions 3 and 4, respectively, together with short-lived phosphorus-centered radical intermediates of type R₂P(= Y)· (5). The radicals 5 dimerize to give R₂P(Y)–(Y)PR₂ (6). Both 3 and 4 are remarkably persistent with half-lives of more than 1 month in THF (tetrahydrofuran) at 300 K.