Snezhana Momchilova

CHELATISIERTE ENOLATE VON α-PHOSPHONYLIERTEM ACETALDEHYD

Abstract Es wird gezeigt, daβ mit Lithiumbutyl bei tiefen Temperaturen das Lithiumenolat 6 aus 2 zuganglich ist, wahrend bei Normaltemperatur 2 mit LiBu oder Zinkacetat bevorzugt unter Aldolkondensation zu den Metall-Komplexen des doppelt phosphonylierten Butadienolats oder dem freien E-Enol 8 reagieren. Die Verbindungen werden NMR-spektroskopisch charakterisiert. Einmal gebildetes Li-Enolat 6 ist stabil und zeigt einen selektiven HID-Austausch. It is demonstrated that the lithium enolate 6 is available from 2 with lithiumbutyl at reduced temperature, while the reaction of 2 with Li-butyl or zinc acetate at normal temperature preferably yields the metal-complexes of the doubly phosphonylated butadienolate or the free E-enol 8 via aldolkondensation. The compounds are characterized by nmr-spectroscopy. Once formed Li-enolate 6 is stable and shows a selective H/D-exchange.

Synthesis and Structure of Complexes of the Diethyl Ester of 2-Dimethylamino-2-oxoethylphosphonic Acid with Lanthanide Nitrates

The lanthanide complexes LnL 2 (NO 3 ) 3 ( 3a-g ) are obtained where Ln is La, Sm, Yb, Er, Ce, Eu, Gd, and L is the diethyl ester of 2-dimethylamino-2-oxoethylphosphonic acid [(C 2 H 5 O) 2 P(O)CH 2 CON(CH 3 ) 2 ] 1 . They are characterized by elemental analysis, i.r. and NMR spectroscopy. The crystal structure of 3a is determined by single crystal X-ray diffraction. The complex is found to crystallize in the triclinic space group P 1 with a = 8.4220(17) Å, b = 11.123(2) Å, c = 17.560(4) Å, f = 87.20(3);, g = 82.27(3);, n = 76.89(3);, V = 1587.3(5) Å 3 , Z = 2, calcd = 1.614 mg/m 3 , R = 0.047, R w = 0.107, S = 1.034 for 5762 reflections with I > 2 (I). The structure contains monomeric units of the complex with the lanthanum atom coordinated by 10 oxygen atoms, six of them from the three bidentate nitrate ions and four from the two phosphonate ligands. The coordination is realized by both phosphoryl and amide-carbonyl oxygen atoms. The stereochemistry of the starting ligand 1 is investigated by NMR spectroscopy.

Structures of threo(RR,SS) diethyl ester of 2-hydroxy-1,2-diphenylethylphosphonic acid and (±)diethyl ester of (1-hydroxycyclopentyl)(2-methylphenyl)methylphosphonic acid

The crystal structures of threo(RR,SS) diethyl ester of 2-hydroxy-1,2-diphenylethylphosphonic acid (1) and of (±)diethyl ester of (1-hydroxycyclopentyl)(2-methylphenyl)methylphosphonic acid (2) have been solved by X-ray methods. They are built up in a similar way to centrosymmetric dimers of hydrogen-bonded molecules. The orientation of the substituents around the central C-C bond in both molecules fulfills the requirement for the least spatial hindrance. The observed shift of theυoh stretching frequencies from 3312(1), 3346 (2) cm−1 in solid to 3408(1), 3450(2), in diluted (10−3M) tetrachloromethane solution, indicates the formation of intramolecular hydrogen-bonded species.

(HYDROXYALKENYL)-DIPHENYLPHOSPHINE OXIDES, THEIR LITHIUM SALTS AND ZINC COMPLEX

Abstract The synthesis and structural characteristics of the lithium salt and zinc complex of Ph2P(O)CPh[dbnd]CHOH 1 are described. While the lithium salt 2 is a stable mixture of (E)- and (Z)-enolate forms 2b and 2c, the zinc complex 3 seems to coordinate as a chelate of phosphonate and acetate groups with some dynamic behaviour in solution. Additionally, the oxide Ph2P(O)CH[dbnd]CHC[P(O)Ph2][dbnd]CHOH 5 and its lithium salt 6 are obtained and their structures and conformations elucidated by NMR spectroscopy (1H, 31P, 13C).

SYNTHESIS AND STRUCTURE OF THE COMPLEXES OF ESTERS OF SOME PHOSPHONIC ACIDS AND AMIDES WITH MOLYBDENUM DIOXODICHLORIDE

ABSTRACT The complexes LċMoO2Cl2 (2), L′·MoO2Cl2 (4), L′′·MoO2Cl2 (6) and L′′′ċMoO2Cl2 (8) were obtained by the reaction of MoO2Cl2 and the ligands: L=diethyl ester of 2-dimethylamino-2-oxoethylphosphonic acid (1), L′=diethyl ester of 2-amino-2-oxoethylphosphonic acid (3), L′′=tetraethyl ester of methylenediphosphonic acid (5) and L′′′=tetraethylester of ethylenediphosphonic acid (7). They were characterized by elemental analyses, IR and NMR spectroscopy. The crystal structure of the diphosphonate complex (6) was determined by single crystal X-ray diffraction. The complex was found to crystallize in the monoclinic space group P21/n with a=14.999(9) Å, b=7.823(9) Å, c=16.181(10) Å, β=101.962(13)°, V=1857(3) Å3, Z=4, ρ calcd=1.742(3) mg/m3, R=0.0679, R2w=0.1706, S=1.144 for all 5295 reflections. The structure contains monomeric units of the complex with a sixfold-coordinated Mo atom having a distorted octahedral coordination geometry. The methylenediphosphonate ligand (1) is bonded to the molybdenum atom in a bidentate manner by both P˭O groups.

LANTHANIDE COMPLEXES WITH PHOSPHINE OXIDE AND PHOSPHONATE LIGANDS

Abstract The complexes LnL′3.xH2O (4) and LnL″3.xH2O (5) were obtained from the reaction of 2-(diphenylphosphinoyl)-2-phenylethenol [L′H, (1)], diethyl (2-oxo-1-phenyl)ethylphosphonate [L″H, (2)] and several lanthanide nitrates (3). Two different procedures were applied: in methanol-water solution and potassium hydroxide (procedure A) or in anhydrous tetrahy-drofuran and sodium (procedure B). The IR and NMR data prove the enolate structure of the complexes and bidentate coordination of the metals by the ligands. On the basis of these spectral data, all complexes have a chelate structure. Only the diamagnetic lanthanum derivatives (4a and 5a) can be identified as mixtures of (Z)- and (E)-isomers by NMR spectroscopy. The coordinating Dower of the phosphine oxide (1) is used to separate lanthanum ions from aqueous solutions by liquid-liquid extraction.

Sodium and Potassium Derivatives of 2-(Diphenylphosphinoyl)-2-Phenyl-Ethenol: Synthesis, Structure and Reactivity

The sodium and potassium derivatives of 2-(diphenylphosphinoyl)-2-phenylethenol (2 and 3, respectively) are obtained and their (E)-enolate structure is proved by spectroscopic methods. The study of their reactivity shows that regiospecific O-acylation of 2 and O-alkylation of 3 takes place, the corresponding 1-acetoxy-2-(diphenylphosphinoyl)-2-phenyl-ethene 4 and 1-benzyloxy-2-(diphenylphosphinoyl)-2-phenyl-ethene 5 is isolated. The reaction of carbonyl olefination is not observed.