A PETERSON OLEFINATION REACTION USING SILYL-SUBSTITUTED SULFONAMIDE CARBANIONS. SYNTHESIS OF VINYLIC SULFONAMIDES

Abstract

α-Trimethylsilyl-substituted sulfonamides RCH(SiMe₃)SO₂N(CH₃)₂ (3), (R[dbnd]H, CH₃ and C₆H₅) are synthetized in almost quantitative yields. Their lithium derivatives 4 undergo a smooth Peterson olefination reaction with nonenolisable carbonyl compounds to give good to excellent yields of vinylsulfonamides 6. With R[dbnd]H, the reaction is highly E-stereoselective. Moderate stereoselectivity is obtained in the cases of R[dbnd]CH₃ and R[dbnd]C₆H₅.     

REACTION OF SCHIFF BASE OF THIOHYDRAZIDES WITH P(NR2)3

Abstract

Three pathways were observed in the reactions of Schiff bases of Thiohydrazides with P(NR₂)₃. (a) MeS-R₂N exchange: MeS-C([dbnd]S)-NHN[dbnd]CHPh (1) reacted with P(NR₂)₃ led to new Schiff bases, R₂N-C([dbnd]S)-NHN[dbnd]CH = Ph (2). (b) Cleavage of C[dbnd]S bond and the formation of P[dbnd]S bond: H₂N-C([dbnd]S)-NHN[dbnd]CH = Ph (3) reacted with P(NR₂)₃ gave rise to the thiophosphoric amide. (Et₂N)₂P([dbnd]S)-NH-CH = N-N[dbnd]CH-Ph (4). (c) Formation of thiadiazole and triazole: Schiff bases 2a and H₂N(MeS)C = N-N[dbnd]CH-Ph (6) reacted with P(NR₂)₃ respectively and produced 5-dimethylamino-2-phenyl-2,3-(2H)-1,3,4-thiadiazole (5) and 5-methylthio-2-phenyl-2,3-(2H)-1,3,4-triazole (7).     

SYNTHESIS AND NMR CHARACTERIZATION OF P-VINYL SUBSTITUTED PHOSPHAZENE PRECURSORS1

Abstract

The reactions of either PhPCl₂ or PCl₃ with (Me₃Si)₂NLi followed by H₂C[dbnd]CHMgBr were used to prepare the new P-vinyl substituted [bis(trimethylsilyl)amino]phosphines, (Me₃Si)₂NP(R)CH[dbnd]CH₂ [1: R=Ph, 2: CH[dbnd]CH₂, 3: R=Me, and 4: R=N(SiMe₃)₂]. Oxidative bromination of phosphines 3–1 afforded the P-bromo-P-vinyl-N-(trimethylsilyl)phosphoranimines, Me₃SiN[dbnd]P(CH[dbnd]CH₂)(R)Br [5: R=Ph, 6: R=CH[dbnd]CH₂, 7: R=Me], which, upon treatment with CF₃CH₂OH/Et₃N, were subsequently converted to the P-trifluoroethoxy derivatives, Me₃SiN[dbnd]P(CH[dbnd]CH₂)(R)OCH₂CF₃ [8: R=Ph, 9: R=CH[dbnd]CH₂, 10: R=Me]. Compounds 1–10, which are of interest as potential precursors to P-vinyl substituted poly(phosphazenes), were fully characterized by elemental analyses (except for the thermally unstable P-Br derivatives 5–7) and NMR spectroscopy (¹H, ¹³C, and ³¹P) including complete analysis of the vinylic proton splitting patterns via HOM2DJ experiments.     

STRUCTURES OF PHOSPHAETHYLENES AND A 1-PHOSPHAALLENE CONTAINING PHOSPHORUS IN LOWER COORDINATION STATE

Abstract

The X-ray analyses of sterically protected Z-2-t-butyldimethylsilyloxy-2-phenylphosphaethylene (Z-2) and 3,3-diphenyl-1-phosphaallene (3) were carried out and the structures of the parent compounds, HP[dbnd]CH₂ and HP[dbnd]C[dbnd]CH₂, were optimized by ab initio methods.     

Die Schwingungsspektren der Reihe [NPCl2]3 ċ [NCCl]3

Vibrational Spectra of the Series [NPCl₂]₃ ? [NCCl]₃ The vibrational spectra of the six-membered ring systems [NPCl₂]₂[NCCl] and [NPCl₂][NCCl]₂ are reported and discussed together with the spectra of [NPCl₂]₃ and [NCCl]₃.     

Synthesis and reactivity of silylated phosphorus compounds

Abstract

The preparative and derivative chemistry of several silylated (methylene)phosphines including (Me₃Si)₂NP[dbnd]CHSiMe₃, MesP[dbnd]C(SiMe₃)₂, and a stable 1-phosphadiene system is reported.     

New Strategies in Preparing Organo-Substituted Cyclophosphazenes

Abstract

Nucleophilic addition of a copper-phosphazene anion [(NPCl₂)₂NPR]₂Cu (R = alkyl) to an aldehyde or ketone, followed by acid hydrolysis, leads to the formation of geminal alkyl(hydroxy-alkyl) derivatives in reasonable to high yields.

Isocyanato cyclophosphazenes provide another entrance to organo-substituted derivatives, in which (NPCl₂)₂ NPNH₂ NCO appears to be a versatile starting material. Interesting differences are observed between the reactions of (NPCl₂)₃ with alkali cyanates and silver cyanate in the presence of an alcohol, using acetonitrile as a solvent.     

Imides of 2-Trifluoroacetylphenol and other Trifluoracetic acid Esters: Novel Reactions with Phosphorus(III) Derivates

Abstract

The imido derivates of 2-trifluoroacetylphenol, 1 (R¹=H, Me, iPr) react with the isocyanatophosphites (R²O)₂PNCO, 2 (R²[dbnd]Et, R²-R²[dbnd]CMe₂-CMe₂) to yield the bicyclic compounds 3, wheras in case of 1 (R¹[dbnd](CH₂)₂NMe2) the λ³σ³P compounds 4 are found. The phosphorus(III) chlorides R3PC12 (R³[dbnd]Ph, OEt) and 1 (R¹[dbnd]H, Me) give rise to furnish the tricyclic phosphoranes 5. However with 1 (R¹[dbnd]iPr) phosphite 6 is obtained, which adds hexafluoracetone to give the 1,3,2λ⁵σ⁵-dioxaphospholane 7. 2-(Trifluoracetoxy)pyridine 8. reacts with Tris(trimethylsily1)phosphite to yield the bis(phosph0nate) 10. Some molecular structures are discussed on the basis of x-ray diffraction results.     

CARBODIPHOSPHAN (2.4.6-tBu3C6H2[sbnd]P[dbnd]2)C: REAKTION MIT ELEKTROPHILEN

Abstract

The reaction of Ar[sbnd]P[dbnd]C[dbnd]P[sbnd]Ar (Ar=2.4.6-^tBu₃C₆H₂) with electrophiles (H⁺, S₈) proceeds at the phosphorus atom with subsequent cyclisation of an o-^tbutyl group.     

SYNTHESIS AND CHARACTERIZATION OF THE FIRST BORANE ADDUCTS AND BORON CATIONS OF SOME N-ALKYL AND N-AMINOTRIPHENYLPHOSPHORANIMINES

Abstract

The first borane adducts of N-alkyl and N-aminotriphenylphosphoranimines, Ph₃P[dbnd]N—R, were prepared by two different general synthetic methods. The first method involved displacement of THF (tetrahydofuran) from THF-borane by the free imines, and the second employed the reaction of LiBH₄ with iminium bromides, Ph₃P[dbnd]N(R)HBr, in diethyl ether. Imine boranes, Ph₃P[dbnd]N(R)BH₃, were synthesized where R [dbnd] methyl, ethyl, n-propyl, isopropyl, isobutyl, t-butyl. dimethylamino, phenylamino, and methyl, phenylamino as the nitrogen attached groups. Symmetrical boron cations, (Ph₃P[dbnd]NR)₂, BH₂ ⁺, where R = methyl, ethyl, and n-propyl, were synthesized by displacement of iodide from in-situ generated iodoborane adducts, Ph₃P[dbnd]N(R)BH₂I, by the free imines. An attempt to form an unsymmetrical boron cation from (CH₃)₃ NBH₂I and Ph, P[dbnd]N(n-C₃H₇) resulted only in a mixture of the corresponding symmetrical boron cations. Physical, chemical and spectral properties of the borane adducts and boron cations, namely thermal and hydrolytic stabilities, infrared and NMR data are presented. Oxidative and reductive stabilities of the boron cations were studied. The borane adducts can be chlorinated with either HCI or Ph₃CCI. Relative base strengths of some imines were determined by following the exchange of BH₃ between borane adducts of (CH₃)₃ N or 4- (CH₃)C₅H₄ N and the imines via NMR.     

STEREOSELECTIVE SYNTHESIS OF MONOFLUORO-OLEFINS FROM DIISOPROPYL (CARBOETHOXYFLUORO-METHYL)PHOSPHONATE

Abstract

Treatment of ethyl oxalyl chloride or methyl oxalyl chloride with lithium diisopropyl(carboethoxyfluoromethyl)phosphonate[(i-PrO)₂P(O)CFCO₂Et]^?Li⁺ 2 followed by in siru nucle-ophilic addition with methylmagnesium iodide or vinyl magnesium bromide affords with exclusive E-stereoselectivity formation of diethyl-2-fluoro-3-methyl fumarate (CH₃)(C0₂Et)C[dbnd]CFCO₂Et 4 or 75% of the E-isomer of a-fluoro-P-vinyl-a,P-unsaturated diester (E,Z)-(CH₂[dbnd]CH)(CO₂C₂H₅)C[dbnd]CFCO₂Et 5, respectively. However, direct reaction of ethyl pyruvate with 2 gives the fluoro-olefin (CH₃)(CO₂Et)C[dbnd]CFCO₂Et 4 with 79% E-stere-oselectivity. The E/Zratio of (CH₂[dbnd]CH)(CO₂Et)C[dbnd]CFCO₂Et 5 depends on the HMFT or DMPU cosolvents present in the reaction mixture.     

REACTION DES ENOLATES MASQUES DE SILICIUM ISSUS WESTERS DE TRIMETHYLSILYLE AVEC LES DERIVES CARBONYLES α,β-INSATURES

Abstract

Bis(trimethylsilyl) ketene acetals RCH[dbnd]C[OSi(CH₃)₃]₂ 1 add to PhCH[dbnd]CH[sbnd]COR¹ 2 in the presence of catalytic amounts (10%) of TiCl₄ leading, in good to excellent yields to the corresponding β-hydroxy or δ-ketoacids. Under kinetic control, the regioselectivity of the reaction markedly depends on the nature of R and R¹. Mixtures of 1,2 and 1,4 products are formed in some of the cases; in others, solely Michael or aldol adducts are obtained. On the contrary, the stereoselectivity, which ranges from zero to moderate, is slightly influenced by R and R¹.

It is also shown that trimethylsilyl ester of α-trimethylacetic acid (CH₃)₃SiCH₂CO₂Si(CH₃)₃ 5 add to 2 in the presence of TBAF (10%) in THF.     

Elucidation of the Reaction Products of Acetonitrile with Phosphorus Pentachloride

Abstract

The reaction of acetonitrile with PCl, results in the ionic compounds (1) to (4) containing the trichloro[2-chloro-2-[(trichlorophosphoranyli-dene)amino]ethenyl]phosphorus cations and not in the compounds [CH2?C?NPCl₃]PCl₆1 or trichloro[2-chloro-1 -[(trichlorophosphoranyli-dene)amino] ethenyl]phosphorus hexachlorophosphate (5) as assumed from ³¹P-NMR spectra [2, 3]. The crystal structures of the compounds (1) to (4) were determined with X-rays at 95K. As observed for the CI-C(NPCl₃); cation all the cations show cis-trans conformations with respect to their CI-C-X-P torsion angles. The wcl3 groups of the cations have two different orientations with one C?N?P?CI torsion angle of about 0° (cis) as in (1) or about 180° (trans) as in (3) and (4). In the salt (2) there are two formula units in the asymmetric unit with one cation showing the cis and the other showing the tram conformation.     

Hydrogen-bonded Networks in Crown Ether Complexes of Hydrated Metal Ions

Abstract

The hydrated metal nitrates (M(NO₃)₃.6H₂O, M[dbnd]Co, Ni, Cu, Zn and Cd) have been crystallised from water in the presence of 18-crown-6 and their structures determined by X-ray crystallography. In the case of copper, a pseudo four-coordinate square planar complex resides in an extended six-coordinate octahedral array which is further bound in a single-stranded one-dimensional hydrogen bonded polymeric mode. For M[dbnd]Co,Ni,Zn and Cd isomorphous complexes are isolated where the octahedral [M(H₂O)₅(NO₃)⁺ cation resides in a two-dimensional polymeric network through hydrogen bonds between the water ligands and either the crown ether oxygens or unbound nitrate ions or water molecules.     

VERBINDUNGEN MIT DEM 1,3-DIMETHYL-1,3- DIAZA-2-PHOSPHETIDIN-4-ON GRUNDGERüST: SYNTHESE VON 1,3-DIMETHYL-2-PHENYLIMINO- 1,3-DIAZA-2λ4-PHOSPHETIDIN-4-ON-DERIVATEN. RÖNTGENSTRUKTURANALYSE VON 4,6- DIMETHOXY -5,10-DIPHENYL-1,3,7,9- TETRAMETHYL-l,3,5,7,9,10-HEXAAZA- 4λ5,6λ55-DIPHOSPHADISPIRO[3.1.3.1]DECAN-2,8-DION

Abstract

Die Umsetzung einer Reihe von λ³P-Diazaphosphetidinonen, MeNC(:O)N(Me)PY (Y [dbnd] NEt₂: 1, N(CH₂)₄; 2, NPh₂; 3, OMe; 4, N(cyc)₂; 5), mit Phenylazid wird beschrieben. Die dabei primär entstandenen 2-Phenylimino-λ⁴P-diazaphosphetidinone, MeNC(:O)N(Me)P(:NPh)Y sind mit Ausnahme des sterisch anspruchsvollen Dicyclohexylderivats, Y [dbnd] N(cyc)₂; 12, unbeständig und dimerisieren rasch zu den entsprechenden Diazadiphosphetidinen, 7 und 9–11. Aus 7 bildet sich in Lösung unter Abspaltung von MeN[dbnd]C[dbnd]NMe das A4P, λ⁴P,λ⁵P-Diazadiphosphetidin 8. Die neuen Verbindungen 8–12 wurden analytisch, ₁H-, ₁₃C- und ³¹P-NMR-spektroskopisch sowie durch ihre Massenspektren charakterisiert. Darüber hinaus wurde von Verbindung 11 eine Röntgenstrukturanalyse durchgeführt. Das Molekül besitzt kristallographische zweizählige Symmetric. Die Geometrie am Phosphor ist verzerrt trigonal bipyramidal, mit P—N-Bindungslängen 173.9. 179.2 pm (axial) sowie 168.3, 168.7 pm (äquatorial).

Compounds involving the 1,3-dimethyl-1,3-diaza-2-phosphetidin-4-one framework: Synthesis of 1,3- dimethyl-2-phenylimino-l,3-diaza-2λ⁴-phosphetidin-4-one derivatives. X-ray crystal structure analysis of 4,6-dimethoxy-5,10-diphenyl-l,3,7,9-tetramethyl- 1,3,5,7,9,10-hexaaza-4λ⁵,6λ⁵-diphosphadispiro- [3.1.3.l]decan-2,8-dione.

The reactions of a series of λ³P-diazaphosphetidinones MeNC(:O)N(Me)PY (Y [dbnd] NEt₂,; ₁, N(CH₂)₄; 2, NPh2,; 3, OMe; 4, N(cyc)₂; 5), with phenyl azide are described. The initially formed 2-phenylimino-λ⁴P-diazaphosphetidinones, MeNC(:O)N(Me)P(:NPh)Y, are. except for the bulky dicyclohexyl derivative 12, unstable and dimerize rapidly to the corresponding diazadiphosphetidines, 7 and 9–11. The λ⁴P,λ⁴P-diazadiphosphetidine 8 is formed from 7 in solution by elimination of MeN[dbnd]C[dbnd]NMe. The novel compounds 8–12 were characterized by analysis, n.m.r. and mass spectroscopy; additionally, an X-ray crystal structure analysis of 11 was carried out. The molecule possesses crystallographic twofold symmetry. The P-N bond lengths are 173.9, 179.2 pm (axial) and 168.3, 168.7 pm (equatorial).     

Pt(II) ASSISTED DEOXYGENATION OF COORDINATED SULFOXIDES BY HYDROCHLORIC- OR HYDROBROMIC ACID

Abstract

The interaction of the complexes (Et₄ N)[Pt(R₂ SO)X₃] (R = Me, Et, CH₂ Ph, X [dbnd] C1; R [dbnd] Me, X [dbnd] Br) and cis-[Pt(Me₂ SO)₂ Cl₂] with concentrated HX (X [dbnd] Cl. Br) results in the reduction of the coordinated sulfoxides and oxidation of Pt(II) to Pt(IV). As a result [Pt(R₂ S)X₅ and [Pt(R₂S)₂ X₄] are formed. Ligands R₂ S can be removed from the complexes and isolated in a free state.     

SYNTHESIS AND CHARACTERISATION OF DIORGANOANTIMONY(III) COMPLEXES OF THIOSEMICARBAZONES

Abstract

The interaction of the sodium salts of thiosemicarbazones with diphenylantimony chloride in 1:1 molar ratio in benzene solution lead to the formation of derivatives, Ph₂Sb[SC(NH₂)NN: C(R)R′] where R = H; R′ [dbnd] C₆H₅, CH₃OC₆H₄, C₆H₅CH[dbnd]CH, and R′ [dbnd] CH₃; R′[dbnd]C₆H₅, CH₃OC₆H₄, C₆H₄CH₃, respectively. The resulting complexes have been characterised on the basis of elemental analyses and molecular weight determination. The mode of bonding of the ligands with the metal atom has been proposed on the basis of I.R., ¹H and ¹³C NMR studies. All these ligands are found to behave as monofunctional bidentate moiety in these complexes.     

Quantum-Chemical Investigation of Structure and Vibration Spectrum of [C(NPCl<Subscript>3</Subscript>)<Subscript>3</Subscript>]<Superscript>+</Superscript> Cation

Structural parameters of the cation [C(NPCl₃)₃]⁺ in vacuum and in acetonitrile are calculated by the methods RHF/6-311G(3d₆), RHF/6-31(3d₅) and B3LYP/6-311(3d₅f₇). Formation energy of the free adduct (MeCN) 2[C(NPCl₃)₃]⁺ is calculated and nonspecific character of interaction of the cation with liquid acetonitrile is established. Vibration spectrum of the cation is calculated and theoretical interpretation of IR and Raman spectra of the salt [C(NPCl₃)₃]⁺[SbCl₆]^? is refined.     

Spectroscopic and theoretical studies of N-trichlorophosphazotrifluoroacetyl,CF3C(O)NPCl3 and N-trichlorophosphazotrichloroacetyl,CCl3C(O)NPCl3

FTIR, Raman and NMR spectra of N-trichlorophosphazotrifluoroacetyl, CF₃C(O)NPCl₃ (1) and N-trichlorophosphazotrichloroacetyl, CCl₃C(O)NPCl₃ (2) were obtained. The experimental data are compared with results of ab initio and density functional theory (DFT) calculations. According the theoretical studies the main conformer for both molecules possesses C_s symmetry (CO bond syn respect to the NP bond). The preference of the syn conformation has been rationalized based on the natural bond orbital formalism. The vibrational spectra of 1 in the liquid phase and 2 in the solid phase are in good agreement with theoretical results.     

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.