Phosphaniminato-Komplexe des Antimons. Die Kristallstrukturen von [Sb2Cl5(NPMe3)2][SbCl6] · CH3CN und [SbCl(NPPh3)]2[SbCl6]2 · 6 CH3CN

Phosphorane Iminato Complexes of Antimony. The Crystal Structures of [Sb₂Cl₅(NPMe₃)₂][SbCl₆] · CH₃CN and [SbCl(NPPh₃)]₂[SbCl₆]₂ · 6 CH₃CN The title compounds are formed by reaction of antimony pentachloride in acetonitrile solution with the phosphorane iminato complexes SbCl₂(NPMe₃) and SbCl₂(NPPh₃), respectively, which themselves are synthesized by reaction of antimony trichloride with Me₃SiNPR₃ (R = Me, Ph). The complexionic compounds are characterized by ¹²¹Sb Mössbauer spectroscopy and by crystal structure determinations. [Sb₂Cl₅(NPMe₃)₂][SbCl₆] · CH₃CN: Space group P4₁, Z = 4, 3 698 observed unique reflections, R = 0.022. Lattice dimensions at ?60°C: a = b = 1 056.0(1), c = 2 709.6(2) pm. The structure consists of SbCl₆^? ions and cations [Sb₂Cl₅(NPMe₃)₂(CH₃CN)]⁺, in which one Sb^III atom and one Sb^V atom are bridged by the N atoms of the phosphorane iminato ligands. [SbCl(NPPh₃)]₂[SbCl₆]₂ · 6 CH₃CN: Space group P1 , Z = 2, 5 958 observed unique reflections, R = 0.033. Lattice dimensions at ?60°C: a = 989.4(11), b = 1 273(1), c = 1 396(1) pm, α = 78.33(7), β = 77.27(8)°, γ = 86.62(8)°. The structure consists of SbCl₆^? ions and centrosymmetric cations [SbCl(NPPh₃)(CH₃CN)₂]₂²⁺, in which the antimony atoms are bridged by the N atoms of the phosphorane iminato ligands.     

Phosphaniminato-Trichloroselenate(II): Synthese und Kristallstrukturen von [SeCl(NPPh3)2]+SeCl3− und [Me3SiN(H)PMe3]2+[Se2Cl6]2−

Phosphorane Iminato-Trichloroselenates(II): Syntheses and Crystal Structures of [SeCl(NPPh₃)₂]⁺SeCl₃^? and [Me₃SiN(H)PMe₃]₂⁺[Se₂Cl₆]^2? [SeCl(NPPh₃)₂]⁺SeCl₃^? has been synthesized by the reaction of Se₂Cl₂ with Me₃SiNPPh₃ in acetonitrile solution, forming orangered crystals, whereas red crystals of [Me₃SiN(H)PMe₃]₂⁺[Se₂Cl₆]^2? were obtained by the reaction of Me₃SiNPMe₃ with SeOCl₂ in acetonitrile solution. Both complexes were characterized by X-ray structure determinations. [SeCl(NPPh₃)₂]⁺SeCl₃^?: Space group P2₁/n, Z = 4, structure solution with 7 489 observed unique reflections, R = 0.057. Lattice dimensions at ?60°C: a = 1 117.0; b = 2 241, c = 1 407.5 pm, β = 95.61°. In the cation [SeCl(NPPh₃)₂]⁺ the selenium atom is φ-tetrahedrally coordinated by the chlorine atom and by the nitrogen atoms of the phosphorane iminato ligands, whereas the anion SeCl₃^? has a T-shaped structure with φ-trigonal-bipyramidale surrounding of the selenium atom. [Me₃SiN(H)PMe₃]₂⁺[Se₂Cl₆]^2?: Space group P2₁/c, Z = 4, structure solution with 2 093 observed unique reflections, R = 0.080. Lattice dimensions at ?70°C: a = 956, b = 828, c = 1 973 pm, β = 93.80°. The structure consists of [Me₃SiN(H)PMe₃]⁺ ions and planar [Se₂Cl₆]^2? anions, in which the selenium atoms are bridged nearly symmetrically by two chlorine atoms.     

Synthese und Kristallstrukturen der Phosphaniminato-Komplexe [MCl2(NPPh3)]2 mit M = Al und Ga, [SbCl2(NPMe3)(DMF)]2 sowie des Phosphanimin-Komplexes [Ph3PNH · BF3] · THF

Syntheses and Crystal Structures of the Phosphorane Iminato Complexes [MCl₂(NPPh₃)]₂ with M = Al and Ga, [SbCl₂(NPMe₃)(DMF)]₂, and of the Phosphorane Imine Complex [Ph₃PNH · BF₃] · THF The phosphorane iminato complexes [MCl₂(NPPh₃)]₂ with M = Al and Ga and [SbCl₂(NPMe₃)(DMF)]₂ are formed as colourless crystals by reactions of the anhydrous trichlorides MCl₃ (M = Al, Ga, Sb) with the corresponding silylated phosphorane imines Me₃SiNPR₃ in acetonitrile and in dimethyl formamide, respectively. The phosphorane imine derivative [Ph₃PNH · BF₃] · THF is formed from Me₃SiNPPh₃ and boron trifluoride etherate in boiling tetrahydrofuran. The compounds are characterized by their i. r. spectra and by crystal structure analyses. [AlCl₂(NPPh₃)]₂ : Space group P1 , Z = 1, structure solution with 1 585 observed unique reflections, R = 0.061. Lattice dimensions at ?70°C: a = 917.6, b = 1 053.5, c = 1 145.2 pm, α = 111.72°, β = 100.80°, γ = 109.95°. [GaCl₂(NPPh₃)]₂ : Space group P1 , Z = 1, structure solution with 2 586 observed unique reflections, R = 0.066. Lattice dimensions at ?70°C: a = 917.5, b = 1 058.3, c = 1 153.7 pm, α = 105.52°, β = 107.75°, γ = 109.88°. In both compounds the metal atoms are linked to planar M₂N₂ four-membered rings via the N-atoms of the phosphorane iminato groups. [SbCl₂(NPMe₃)(DMF)]₂ : Space group P2₁/n, Z = 4, structure solution with 3 805 observed unique reflections, R = 0.038. Lattice dimensions at ?70°C: a = 1 913.0, b = 726.8, c = 2 040.7 pm, β = 113.62°. The unit cell contains two symmetry independent dimeric molecules, in which the antimony atoms are centrosymmetricly μ₂ linked via the N-atoms of the phosphorane iminato groups. Along with the oxygen atom of the dimethyl formamide molecule the Sb atoms achieve a ψ-octahedral environment. [Ph₃PNH · BF₃] · THF : Space group C2/c, Z = 8, structure solution with 2 048 observed unique reflections, R = 0.058. Lattice dimensions at ?70°C: a = 2 460.4, b = 869.2, c = 1 978.0 pm, β = 116.35°.     

The Reaction of (N‐Isocyanimino)triphenylphosphorane with Biacetyl in the Presence of Aromatic Carboxylic Acids: Efficient One‐Pot Three‐Component Reaction for the Synthesis of 3‐(5‐Aryl‐1,3,4‐oxadiazol‐2‐yl)‐3‐hydroxybutan‐2‐one Derivatives

Reactions of biacetyl (=butane‐2,3‐dione) with (N‐isocyanimino)triphenylphosphorane in the presence of aromatic carboxylic acids proceed smoothly at room temperature and under neutral conditions to afford 3‐(5‐aryl‐1,3,4‐oxadiazol‐2‐yl)‐3‐hydroxybutan‐2‐one derivatives in high yields.     

Tandem Wittig – Reductive annulation decarboxylation approach for the synthesis of indole and 2-substituted indoles

A simple tandem Wittig reaction-reductive decarboxylation route is established for the synthesis of indoles from commercially available o-nitrobenzaldehydes and a stable phosphorane. The method allows access to indoles in a very fast manner without involving any metal or expensive reagents or inert atmosphere. Also 2-substituted indoles are obtained which forms an important core of many biological active compounds.     

3,3-Dimethoxypropylsulfonyl Group: A new versatile protecting and activating group for amine synthesis

3,3-Dimethoxypropylsulfonyl (Dimps) chloride was prepared and used as a new versatile sulfonating agent for ammonia, primary and secondary amines to afford corresponding Dimps-amides in excellent yields. The resulting N-nonsubstituted and N-monosubstituted Dimps-amides, activated amines, were alkylated satisfactorily under new Mitsunobu conditions. The Dimps group was removed by treatment in aqueous solution under acidic followed by basic conditions. Furthermore, epilachnene, the defensive droplets from the Mexican bean beetle, Epilachna varivestis, was synthesized utilizing this Dimps methodology in short steps.     

Bis(triphenylphosphaniminato)niobtrichlorid, [NbCl3(NPPh3)2], ein Komplex mit fünffach koordiniertem Niob

Bis(triphenylphosphorane-iminato)niobium Trichloride, [NbCl₃(NPPh₃)₂], a Complex with Coordination Number Five at the Niobium Atom The title compound has been prepared from niobium pentachloride with Me₃SiNPPh₃ in acetonitrile solution, forming colourless, moisture sensitive crystals. They were characterized by IR spectroscopy and by an X-ray structure determination. [NbCl₃(NPPh₃)₂] crystallizes monoclinically in the space group Cc with four formula units per unit cell, 3682 observed, unique reflections, R = 0.042%. Lattice dimensions at 20°C: a = 1025.1(2); b = 1870.6(6); c = 1832.5(5) pm, β = 91.83(2)°. The niobium atom of the complex is coordinated in a distorted trigonal bipyramidal fashion, while the nitrogen atoms of the two phosphorane iminato ligands are in equatorial position along with one chlorine atom. NbN and PN distances accord with double bonds; with a mean value of 242.0 pm the Nb Cl distances are remarkably long.     

[Cu4(NPMe3)3(O2C?CH3)5] – ein tetramerer Phosphaniminato-Komplex von Kupfer(II). Synthese,Kristallstruktur, magnetisches Verhalten und EPR-Spektrum

[Cu₄(NPMe₃)₃(O₂C? CH₃)₅] – a Tetrameric Phosphorane Iminato Complex of Copper(II). Synthesis, Crystal Structure, Magnetic Behaviour, and EPR Spectrum The title compound and the corresponding benzoate complex [Cu₄(NPMe₃)₃(O₂C? C₆H₅)₅] have been prepared by reactions of copper(II)acetate and copper(II)benzoate, respectively, with Me₃SiNPMe₃ in dichloromethane. Both complexes are characterized by IR spectroscopy. The acetate complex is additionally characterized by the measurement of the magnetic susceptibility, by its EPR spectrum, and by a crystal structure determination. [Cu₄(NPMe₃)₃(O₂C? CH₃)₅] · CH₂Cl₂: Space group I4₁/a, Z = 16, structure solution with 7 960 independent reflections, R = 0.044. Lattice dimensions at ?70°C: a = b = 3 670.6; c = 1 091.9 pm. The structure consists of four Cu atoms which are arranged at the corners of a distorted tetrahedron with Cu…?Cu distances between 290 and 318 pm. Three of the faces of the tetrahedron are linked by μ₃-N atoms of the phosphorane iminato groups. Three of the acetate ligands form chelates, the other two are monofunctionally coordinated. Three of the copper atoms have a planar surrounding, the forth Cu atom has a (4 + 1) coordination.     

Synthese und Kristallstruktur des Selenyl-Phosphaniminato-Komplexes SeO(NPPh3)2

Synthesis and Crystal Structure of the Selenyl-Phosphoraneiminato Complex SeO(NPPh₃)₂ SeO(NPPh₃)₂ has been prepared from SeO₂ and Me₃SiNPPh₃ in a SeO₂ suspension in acetonitrile, forming colourless crystals. The compound is characterized by IR spectroscopy and by a crystal structure determination. Space group P1 , Z = 2, structure solution with 5 344 observed unique reflections, R = 0.064. Lattice dimensions at ?40°C: a = 931.6, b = 947.6, c = 1 762 pm, α = 77.50°, β = 81.78°, γ = 79.23°. The compound forms monomeric molecules in which the selenium atom is φ-tetrahedrally surrounded with bond lengths SeO = 161.7 pm and SeN = 179.9 and 181.6 pm.     

Synthesis of Four- and Five-Membered Heterocycles Derived from an Iminophosphorane

Reactions of an iminophosphorane bearing the Martin ligand with a ketone, an isothiocyanate, and an alkyne gave the corresponding cycloadducts, 1,3,2 u 5 -oxazaphosphetidine, 1,3,2 u 5 -diazaphosphetidine-4-thione, and 1,2 u 5 -azaphosphetine, respectively, while that with dimethyl acetylenedicarboxylate (DMAD) and successive hydrolysis afforded the 1,2 u 5 -oxaphosphole-(2 H )-one. Thermal reactions of the cycloadducts were also studied.