Synthesis of bis(2-haloalkyl) selanes and selenides based on selenium dioxide and terminal alkenes

Selenium tetrahalides generated from selenium dioxide and hydrogen halides (HCl, HBr) reacted with hex-1-ene, hept-1-ene, and oct-1-ene at a SeO₂?alkene molar ratio of 1: 2 to give mixtures of dihalobis-(2-haloalkyl)-λ⁴-selanes (yield 80?90%) and bis(2-haloalkyl) selenides (yield 5?12%). Halogenation of the resulting mixtures afforded 85?93% (calculated on the initial SeO₂) of the corresponding dihalobis(2-haloalkyl)-λ⁴-selanes, and the reduction of the same mixtures with Na₂S₂O₅ gave bis(2-haloalkyl) selenides in 80?86% yield. In the reaction with a SeO₂?alkene ratio of 5: 8, pure dihalobis(2-haloalkyl)-λ⁴-selanes were formed in 84?93% yield. Dichlorobis(2-chloro-2-phenylethyl)-λ⁴-selane was obtained in 72% yield in the reaction of SeO₂?HCl with styrene.     

Acyl- und Alkylidenphosphane. XXV. Molekül- und Kristallstruktur des 1,2-Di(tert-butyl)-3-dimethylamino-1-thio-4-trimethylsilylsulfano-1λ5,2λ3-diphosphet-3-ens

Acyl- and Alkylidenephosphines. XXV. Molecular and Crystal Structure of 1,2-Di(tert-butyl)-3-dimethylamino-1-thio-4-trimethylsilylsulfano-1λ⁵, 2λ³-diphosphet-3-ene The title compound 1 formed in a nearly quantitative yield by decomposition of tert-butyl(N,N-dimethylthiocarbamoyl)trimethylsilylphosphine, crystallizes in the orthorhombic space group P2₁2₁2₁ with {a = 1067.3(1); b = 1077.1(1); c = 1924.6(5) pm; Z = 4} at +20°C. An X-ray structure determination (R_G = 0.038) shows two tert-butyl groups at a four- (P1) and a three-coordinate phosphorus atom (P2) to be placed on different sides of the four membered ring. Characteristic bond lengths as well as the angles at the atoms P1, P2, C3, and C4 inside the ring have already been given above.     

Acyl- und Alkylidenphosphane. XXIV. (N,N-Dimethylthiocarbamoyl)trimethylsilylphosphane und 1,2-Di(tert-butyl)-3-dimethylamino-1-thio-4-trimethylsilylsulfano-1λ5,2λ3-diphosphet-3-en

Acyl- and Alkylidenephosphines. XXIV. (N,N-Dimethylthiocarbamoyl)trimethylsilyl-phosphines and 1.2-Di(tert-butyl)-3-dimethylamino-1-thio-4-trimethylsilylsulfano-1λ⁵, 2λ³-diphosphet-3-ene In contrast to bis(trimethylsilyl)phosphines R? P[? Si(CH₃)₃]₂ 1 {R ? H₃C a ; (H₃C)₃C b ; H₅H₆ c ; H₁₁C₉ d ; (H₃C)₃Si e }, the more nucleophilic lithium trimethylsilylphosphides 4 react with N,N-dimethylthiocarbamoyl chloride already at ?78°C to give (N,N-dimethylthiocarbamoyl)trimethylsilylphosphines 2 . Working up the reaction, a dismutation of the mesityl derivative 2d is observed, whereas the tert-butyl compound 2b dissolved in toluene, eliminates dimethyl(trimethylsilyl)amine to form 1,2-di(tert-butyl)-3-dimethylamino-1-thio-4-trimethylsilyl-sulfano- 1λ⁵, 2λ³-diphosphet-3-ene 6b , nearly quantitatively within several days at +20°C.     

Neue 1λ5, 3λ5-[1,3]Diphosphinine mit Thio- und Selenophosphonsäureresten – Darstellung,Kristallstruktur, NMR-Daten und Komplexbildung mit PdII

Diphosphabenzenes. VI. New 1λ⁵, 3λ⁵-[1,3]Diphosphinines with Thio and Seleno Phosphonic Acid Groups – Preparation, Crystal Structure, NMR Data, and Coordination to Pd^II Preparation of N,N,N′,N′-tetraethyl-P-phenylethinyl phosphonothioacid diamide ( 2 ) and the corresponding phosphonoselenoacid diamide ( 3 ) are described. 2 and 3 react with 1,1,3,3-tetrakis(dimethylamino)-1λ⁵,3λ⁵-diphosphete ( 1 ) to yield 1λ⁵,3λ⁵-[1,3]diphosphinine derivatives 4 and 5 . With (bzl)₂Cl₂Pd 5 forms the coordination compound 6 . All new compounds 2–6 are characterized by their nmr and ir spectra, the structures of 4–6 are further elucidated by X-ray structural analyses.     

Reactions of 1,1,3,3-tetrakis(dimethylamino)-1λ5,3λ5-diphosphete with diphenylchlorophosphane and methyl iodide

1,1,3,3-Tetrakis(dimethylamino)-1λ⁵,3λ⁵-diphosphete, 1, reacts with diphenylchlorophosphane to yield 1,1,3,3-tetrakis(dimethylamino)-4-diphenylphosphanyl-1,2-dihydro-3λ⁵-[1,3]diphosphetium chloride, 2, or, depending on the reaction conditions, the isomer compound 3. The cation of 2 is deprotonated by LiN[Si(CH₃)₃]₂ to give the diphenylphosphanyl-substituted derivative of 1, i.e., compound 4. Methyl iodide adds to 1 to form 1,1,3,3-tetrakis(dimethylamino)-4-methyl-1,2-dihydro-3λ⁵-[1,3]diphosphetium iodide, 6. Deprotonation of 6 with n-butyllithium leads to the monomethyl derivative of 1, i.e., compound 7. Physical properties, NMR spectra, and mass spectra of compounds 2–4, 6, and 7 are described. The results of the X-ray structural analysis of 6 are reported and discussed. © 1996 John Wiley & Sons, Inc.     

Vibrational Study of a New Eight-Membered Si-O-λ5[sgrave]4-P Heterocycle

Abstract

Inorganic heterocycles as potential precursors for polymers or solids enjoy continuing interest Eight-membered heterocycle with a Si₃O-λ⁵-P or Si_ZO₄-λ⁵P skeleton have already been described in the literature^1–2 The synthesis, structure, and properties of heterocycles of the Si-O-λ⁵-P type have been intensively investigated. We present here a simple and convenient synthesis of an eight membered Si₂O₄-O-λ⁵P heterocycle and report both its structure and the corresponding vibrational study.^3–4     

Chelate von Chinolin-8-ol — Derivaten. XI. Eigenschaften und Struktur von Nickelchelaten alkyl-substituierter Chinolin-8-ole bzw. Chinolin-8-thiole

Reactions of 1,1,3,3-Tetrakis(dimethylamino)-1λ⁵,3λ⁵-diphosphete with N? H and P? H Acidic Compounds 1,1,3,3-Tetrakis(dimethylamino)-1λ⁵,3λ⁵-diphosphete, 1 , reacts with aniline to give by opening of the ring 2,2,4,4-tetrakis(dimethylamino)-1-phenyl-1,2λ⁵,4λ⁵-azadiphosphapenta-1,3-diene, 2 , with p-CN? C₆F₄? NH₂ the product is 1-(4-cyano-2,3,5,6-tetrafluorophenyl)-2,2,4,4-tetrakis(dimethylamino)-1,2λ⁵,4λ⁵-azadiphosphapenta-1,3-diene, 3 . t-Butylamine or diethylamine do not react with 1 . Mesitylphosphane opens the ring system 1 forming by reduction of one phosphorus atom {[bis(dimethylamino)phosphanyl]methylidene}bis(dimethylamino)methylphosphorane, 4 . The same product 4 is obtained by reaction with phenylphosphane. The reaction products 2–4 are characterized by their nmr, mass, and ir spectra. Their way of formation is discussed. In 4 a ⁵J(PH), in 3 a ⁷J(CF) long range coupling constant could be identified.     

Alkoxytelluration of Styrene with Tellurium Tetrahalides

Russian Journal of General Chemistry - An efficient synthesis of the earlier unknown trichloro- and tribromo(2-ahkoxy-2-phenylethyl)-λ4-tellanes with yields of 90 to 100% has been developed...     

Übergangsmetall-Komplexe des 1,1,3,3-Tetrakis(dimethylamino)-1λ5,3λ5-diphosphets

Transition Metal Complexes of 1,1,3,3-Tetrakis(dimethylamino)-1λ⁵,3λ⁵-Diphosphete 1,1,3,3-Tetrakis(dimethylamino)-1λ⁵,3aλ⁵-diphosphete, 1 , reacts with W(CO)₆ to yield the isomeric complexes {1,1,3,3-tetrakis(dimethylamino)-1λ⁵,3λ⁵-diphosphete}(pentacarbonyl)tungsten 4 and {1,1,3,3-tetrakis(dimethylamino)-1,4-dihydro-1λ⁵,3λ⁵-[1,3]diphosphetium}(pentacarbonyl)tungsten 5 . With Cr(CO)₆ the complex {1,1,3,3-tetrakis(dimethylamino)-1λ⁵,3λ⁵-diphosphete}(pentacarbonyl)chromium 6 is formed. From the reaction products of Fe₃(CO)₁₂ and Fe₂(CO)₉ with 1 the complex {1,1,3,3-tetrakis(dimethylamino)-1λ⁵,3λ⁵-diphosphete}(pentacarbonyl)iron 7 could be isolated. Properties, nmr, ir and mass spectra of the new compounds are reported. 6 and 7 were characterized by X-ray structure determinations.     

Die Reaktion von λ5-Diphospheten mit COS und CO2 Dihydro-λ5-Phosphete

Reactions of λ⁵-Diphosphetes with COS and CO₂. Dihydro-λ⁵-Phosphetes 1,1,3,3-Tetrakis(dimethylamino)-1λ⁵,3λ⁵-diphosphete, 1 , reacts with COS to yield the (3-oxo-3,4-dihydro-1λ⁵-phosphete-2-yl)-phosphonothioic bis(dimethylamide) 7 . Reaction of dimethyl substituted 1 , i.e. 1,1,3,3-tetrakis(dimethylamino)-2,4-dimethyl-1λ⁵,3λ⁵-diphosphete 4 , with COS and CO₂ results in (3-oxo-2,3-dihydro-1λ⁵-phosphete-2-yl)-phosphonothioic bis(dimethylamide) 9 , and (3-oxo-2,3-dihydro-1λ⁵-phosphete-2-yl)-phosphonic bis(dimethylamide) 10 , respectively. Reaction mechanisms are suggested. 7, 9 and 10 are characterized by their properties, and their nmr, mass-, and ir-spectra. The results of X-ray structural analyses of 9 and 10 are reported and discussed.     

Influence of polymerization conditions on catalytic properties of the TiCl2{η2-1-[C(H)=N(2,3,5,6-tetrafluorophenyl)]-2-O-3,5-di-But-C6H2}2/MAO system in ethylene homopolymerization and copolymerization with α-olefins

Experimental data on ethylene homo- and copolymerization with higher a-olefins (hex-1-ene, oct-1-ene, and dec-1-ene) by the catalytic system TiCl₂{η²-1-[C(H)=N(2,3,5,6-tetrafluorophenyl)]-2-O-3,5-di-Bu^t-C₆H₂}₂/MAO in a Nefras medium and in toluene are presented. The catalytic system provides ultrahigh-molecular-weight polyethylene and incorporation of comonomer units at a level of 2–3 mol.% in both solvents. Nascent copolymers formed in Nefras (petroleum solvent), unlike those obtained in toluene, are characterized by two melting peaks in the DSC thermograms and only one when obtained in toluene. The molecular weight of polyolefins is efficiently controlled by the introduction of hydrogen into the system.     

A new chiral oxazoline derived from camphor and its conversion to (R)-2-methylalkanoic acids

(1S,5R,7R)-(−)-10,10-Dimethyl-3-ethyl-4-oxa-2-azatricyclo[5.2.1.0^1,5]dec-2-ene 2 was prepared in 95% yield from (1S)-1-amino-2-exo-hydroxyapocamphane 1. The chiral oxazoline could be alkylated (LDA/THF/−78°C/RX, RX=ethyl, n-propyl, n-butyl iodides or benzyl bromide) to 3 in 95% yield and >95% diastereoselectivity, and the products hydrolysed to (R)-2-methylalkanoic acids 4 (43–47% yield, 93–98% e.e.).     

The Reaction of Dihalocarbenes with Quadricyclane

The reactions of difluoro-, dichloro- and dibromocarbene with quadricyclane ( 2 ) were examined. In all cases, conversions were low (4–15%), but three distinct reaction courses were observed: cleavage, 1,2-addition, and 1,4-addition. Difluorocarbene gave mainly 6-endo-(2,2-difluorovinyl)-cis-bicyclo[3.1.0]hex-2-ene ( 8 ; 52–89% relative yield), together with minor amounts of exo-3,3-difluorotricyclo[3.2.1.0^2,4]oct-6-ene (7; 13–17%), and 4,4-difluorotetracyclo[3.3.0.0^2,8.0^3,6]octane ( 5 ; 2–4%). Dichlorocarbene gave analogous products, but in relative yields of 35 ( 17 ), 51 ( 11 ), and 12% ( 16 ). The product 11 of 1,2-endo addition underwent further rearrangement to its allylic derivative 12 . A small amount of 1,2-endo addition also occurred (2% of 14 / 15 ). Dibromocarbene gave predominantly products derived from rearrangement of the 1,2-exo (61% of 20 / 21 ) and 1,2-endo adducts (10% of 23 / 24 ). In addition, a significant amount of 4,4-dibromotetracyclo[3.3.0.0^2,8.0^3,6]octane ( 25 ; 21%) was formed. The cleavage product, 6-endo-(2,2-dibromovinyl)-cis-bicyclo[3.1.0]hex-2-ene ( 26 ) was also observed (7%). The yields and product compositions were compared to those obtained from norbornadiene ( 1 ) and found to be entirely different (Table 1), for example no cleavage occurred with difluorocarbene.     

First heterobimetallic MnII/MII(M = Cu,Ni) complexes with open-chain aliphatic schiff-base ligands obtained by direct template synthesis

Four new heterobimetallic complexes [CuL¹][MnCl₄] (1), [CuL²][MnCl₄] (2), [NiL¹][MnCl₄] (3), [NiL²][MnCl₄] (4) (L¹?=?4,6,6-trimethyl-1,9-diamino-3,7-di-aza-nona-3-ene; L²?=?1,15-dihydroxy-7,9,9-trimethyl-3,6,10,13-tetra-aza-pentadeca-6-ene) have been prepared from elemental metals, ethylenediamine dihydrochloride or its N-(2-hydroxyethyl) derivative and acetone by the template condensation reaction. All complexes have been characterized by elemental analysis, IR and UV-Visible spectroscopy. The structures of 2 and 3 have been determined by X-ray crystallography (2: Orthorhombic, Pna2 _1, a?=?20.136(4), b?=?11.185(2), c?=?10.251(2)Å, Z?=?4; 3: Orthorhombic, Pca2 _1, a?=?14.335(2), b?=?11.405(2), c?=?11.154(2)Å, Z?=?4 ). Both crystals consist of alternating complex cations [ML]²⁺ and anions [MnCl₄]^2? linked together by N–H···Cl–Mn and O–H···Cl–Mn hydrogen bonds forming 2D corrugated sheets in (2) and 1D helical chains in (3). Complex 2 represents the first single crystal structure elucidation of the complex containing L².     

Synthese,Eigenschaften und NMR-spektroskopische Untersuchungen an 2,4-Dithioxo-2,4-dimercapto-1,3-diaza-2λ5,4λ5-diphosphetidinen

Synthesis, Properties and N.M.R. Spectroscopic Studies of 2,4-Dithioxo-2,4-dimercapto-1,3-diaza-2λ⁵,4λ⁵-diphosphetidines On the reaction of py · PS₂Cl ( 1 ) or py · PS₂F ( 2 ) (py = Pyridine) with hexamethyl disilazane in a molar ratio of 1:1 the pyridinium salt of the 1,3-bis(trimethylsilyl)-2,4-dimercapto-2,4-dithioxo-1,3-diaza-2λ⁵, 4λ⁵-diphosphetidine ( 3 ) is formed. 3 reacts with MeI to the corresponding methyl ester 9 . There exist two isomers of 9 , probable with cis and trans configuration of the MeS groups, respectively. 3 and 9 have been characterized by i.r., Raman, mass, and NMR spectroscopy. 4 reacts in acetonitrilic solution in the presence of water under hydrolytic cleavage of the trimethyl silyl groups whereas the P₂N₂ ring is preserved. The hydrolysis of 9 has been studied by ¹H-, ³¹P-, and ¹³C-NMR spectroscopy.     

Photochemistry of 6,6-Dimethyl- and 2,2,6,6-Tetramethyl-2H,6H-pyran-3-one

The title compounds 1a and 1b have been synthesized in two steps from the saturated pyran-3-ones 2a and 2b , respectively. Upon irradiation (254 nm or 350 nm) in dilute solutions (10^?3?10^?2M ), compounds 1 undergo a formal [4 + 2] cycloreversion from the excited triplet state to give (2-methylprop-1-enyl)ketene ( 11 ) and either formaldehyde or acetone, ketene 11 being trapped by H₂O or MeOH to afford 4-methylpent-3-enoic acid ( 5 ) or its methyl ester 4 in 75–85% isolated yield. In this (monomolecular) photoreaction, heterocycles 1 differ from their alicyclic counterparts, i.e., 4,4-dimethylcyclohex-2-enone ( 10a ) and 4,4,6,6-tetramethylcyclohex-2-enone ( 10b ), as no rearrangement to a 4-oxabicyclo[3.1.0]hexan-2-one occurs. On the other hand, the photochemical behavior of pyranone 1a in bimolecular reactions (cyclodimerization, [2 + 2] cycloaddition to 2,3-dimethylbut-2-ene) resembles that of enone 10a .     

p-Sulphobenzeneazo-4-(2,3-dihydroxy-5-chloropyridine) as a spectrophotometric reagent for vanadium in steels

Vanadium(V) reacts quickly with the reagent to form a water-soluble orange-red 1:2 complex (λ_max = 495 nm ; ? = 2.5 × 10⁴ l mol^-1 cm^-1). The complex is used to determine 0.04–1.5% vanadium in steels.     

1,1,3,3,5,5-Hexakis(dimethylamino)-λ5-[1,3,5]triphosphinin – Darstellung,Kristallstruktur und NMR-Daten

1,1,3,3,5,5-Hexakis(dimethylamino)-λ⁵-[1,3,5]triphosphinine – Synthesis, Crystal Structure, and NMR Data Preparation of 1,1,3,3,5,5-hexakis(dimethylamino)-λ⁵-[1,3,5]triphosphinine ( 4 ) and the path of its formation from methyl-bis(dimethylamino)difluorophosphorane ( 1 ) and n-butyllithium are described. The chemical behaviour of compounds of type [R₂P=CH–]_n is compared with that of the isoelectronic dichlorophosphazenes [Cl₂P=N–]_n. The structure of 4 is eludicated by n.m.r. spectra and X-ray structural analysis.     

Complex Carbocyclic Skeletons from Aryl Ketones through a Three-Photon Cascade Reaction

Starting from readily available 7-substituted 1-indanones, products with a tetracyclo[5.3.1.0^1,70^4,11]undec-2-ene skeleton were obtained upon irradiation at λ=350 nm (eight examples, 49–67 % yield). The assembly of the structurally complex carbon framework proceeds in a three-photon process comprising an ortho photocycloaddition, a disrotatory [4π] photocyclization, and a di-π-methane rearrangement. The flat aromatic core of the starting material is converted into a functionalized polycyclic hydrocarbon with exit vectors in three dimensions. Ring opening reactions at the central cyclopropane ring were explored, which enable the preparation of tricyclo[5.3.1.0^4,11]undec-2-enes and of tricyclo[6.2.1.0^1,5]undecanes.     

Synthesis of 8-acetoxytetracyclo[4.4.12.5.17.10.01.6]dodec-3-ene and diesters of C1-C5 acids on its basis

Reaction of vinyl acetate with tricyclo[5.2.1^2.5.1.0^2.6]deca-3,8-diene in the presence of nano-TiO₂ (20 nm) catalyst was studied. 8-Acetoxytetracyclo[4.4.1^2.5.1^7.10.0^1.6]dodec-3-ene was obtained in 88.5% yield. Addition of saturated monobasic acids C₁-C₅ to the obtained unsaturated monoester in the presence of the boron trifluoride etherate catalyst was investigated. Corresponding diesters were obtained in 68.1–93.0% yield. They can be used as the additives to synthetic oils and as components of perfumes.