Synthesis,structure, and reactivity of some sterically hindered (Silylamino)phosphines

A series of new (silylamino)phosphines that contain sterically bulky silyl groups on nitrogen were prepared by deprotonation/substitution reactions of the hindered disilylamines t-BuR(2)Si(Me(3)Si)NH (1, R = Me; 2, R = Ph) and (Et(3)Si)(2)NH (3). Sequential treatment of the N-lithio derivatives of 1-3 with PCl(3) or PhPCl(2) and MeLi gave the corresponding (silylamino)phosphines t-BuR(2)Si(Me(3)Si)NP(R')Me (5, R = Me, R' = Ph; 6, R = Ph, R' = Me) and (Et(3)Si)(2)NP(R)Me (11, R = Me; 12, R = Ph) in high yields. Two of the P-chloro intermediates t-BuR(2)Si(Me(3)Si)NP(Ph)Cl (7, R = Ph; 9, R = Me) were also isolated and fully characterized. Hydrolysis of 7 afforded the crystalline PH-substituted aminophosphine oxide t-BuPh(2)SiN(H)P(Ph)(=O)H (10). Thermal decomposition of 7 occurred with elimination of Me(3)SiCl and formation of a novel P(2)N(2) four-membered ring system (36) that contains both P(III) and P(V) centers. Reactions of the N-lithio derivatives of amines 1 and 2 with phosphorus trihalides afforded the thermally stable -PF(2) derivatives t-BuR(2)Si(Me(3)Si)NPF(2) (13, R = Me; 14, R = Ph) and the unstable -PCl(2) analogue 17 (R = Ph). Reduction (using LiAlH(4)) of the SiPh-substituted dihalophosphines 14 and 17 gave the unstable parent phosphine t-BuPh(2)Si(Me(3)Si)NPH(2) (15). The P-organo-substituted (silylamino)phosphines underwent oxidative bromination to afford high yields of the corresponding N-silyl-P-bromophosphoranimines t-BuR(2)SiN=P(R')(Me)Br (18, R = R' = Me; 19, R = Me, R' = Ph; 20, R = Ph, R' = Me) and Et(3)SiN=P(R)(Me)Br (23, R = Me; 24, R = Ph). Subsequent treatment of these reactive PBr compounds with lithium trifluoroethoxide or phenoxide produced the corresponding PO derivatives t-BuR(2)SiN=P(R')(Me)OR' ' (25 and 26, R' ' = CH(2)CF(3); 28-30, R' ' = Ph) and Et(3)SiN=P(R)(Me)OR' (31 and 33, R' = CH(2)CF(3); 32 and 34, R = Ph), respectively. Many of the new compounds containing the bulky tert-butyldiphenylsilyl group, t-BuPh(2)Si, were solids that gave crystals suitable for X-ray diffraction studies. Consequently, the crystal structures of three (silylamino)phosphines (6, 7, and 14), one (silylamino)phosphine oxide (10), one N-silylphosphoranimine (30), and the cyclic compound 36 were determined. Among the (silylamino)phosphines, the P-N bond distances [6, N-PMe(2), 1.725(3) A; 7, N-P(Ph)Cl, 1.68(1) A, 14, N-PF(2), 1.652(4) A] decreased significantly as the electron-withdrawing nature of the phosphorus substituents increased. The N-silylphosphoranimine t-BuPh(2)SiN=PMe(2)OPh (30), which is a model system for poly(phosphazene) precursors, had a much shorter P=N distance of 1.512(6) A and a wide Si-N-P bond angle of 166.4(3) degrees. A similar P=N bond distance [1.514(7) A] and Si-N-P angle [169.9(6) degrees ] were observed for the exocyclic P=N-Si linkage in the ring compound 36, while the phosphine oxide 10 had P-N and P=O distances of 1.637(4) and 1.496(3) A, respectively, and a Si-N-P angle of 134.3(2) degrees.     

Synthesis and reactivity of substituted alkoxymethylphosphonites and their derivatives

Alkoxy‐substituted methylphosphonites and their derivatives are prepared using an organomagnesium method of synthesizing the organophosphorus compounds and alkoxymethylation of various PH acids and their derivatives. Also, certain properties of these promising compounds as important precursors of new functionalized organophosphorue compounds with alkoxymethyl fragments are presented. © 2012 Wiley Periodicals, Inc. Heteroatom Chem 23:281–289, 2012; View this article online at wileyonlinelibrary.com . DOI 10.1002/hc.21015     

Unsymmetrical secondary and tertiary phosphines and their derivatives

Conclusions Previously unknown secondary and tertiary phosphines with various functional groups have been obtained and described.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 2, pp. 414–415, February, 1967.     

Synthesis of several halobisnoradamantane derivatives and their reactivity through the S(RN)1 mechanism

Several bridgehead halobisnoradamantane derivatives (5, 7, 10, and 17) were synthesized from tricyclic diester 1 in good yields using standard methods. The reactivity through the S(RN)1 mechanism of the above compounds and the known halobisethano derivatives 24 and 25a-c was studied. Iodo derivatives 7, 10, and 25a reacted with diphenylphosphide ions in DMSO under irradiation to give the corresponding substitution and reduction products by the S(RN)1 mechanism, while iodo ketone 17 gave a mixture of the rearranged substitution product 36 and the reduction product 18. Formation of 36 takes place through a 1,5-hydrogen migration of the initially formed radical, a kind of process that has been observed for the first time in the S(RN)1 propagation steps. The diiodo derivative 24 reacted with diphenylphosphide ions under similar reaction conditions to give the substitution and/or reduction products 32, 31, 27, 25a, and 26. The intramolecular ET reaction in the monosubstitution radical anion 32*(-) seems to be faster than the intermolecular ET to the substrate, and the monoiodo derivative 25a is a reaction intermediate.     

Tris(polymethoxyphenyl)bismuth derivatives: Synthesis and reactivity

Tris-(polymethoxyphenyl)bismuth diacetate and dichloride derivatives react with C-nucleophiles in basic medium, as well as with N- and O-nucleophiles under copper catalysis to give good to high yields of the corresponding C-, N- and O-arylation products.     

Synthesis of tris(organylthioethyl)phosphines and their derivatives on the basis of the reaction of phosphine with vinyl sulfides

Phosphine generated from the red phosphorus in the system KOH-H₂O-toluene adds regio- and chemoselectively to vinyl sulfides under radical initiation conditions with the formation of tris(2-organylthioethyl)phosphines, which are easily oxidized by elemental sulfur and selenium to the corresponding phosphine sulfides and phosphine selenides in 54–78% yield. The obtained adducts are split when treated with sodium amide in THF to give trivinylphosphine and trivinylphosphine chalcogenides.     

双二茂铁基(三甲硅烷氧基)乙腈的合成与晶体结构

双二茂铁甲酮与三甲基氰硅烷在CH2Cl2中ZnI2催化下加成,得到产率较高的双二茂铁基(三甲硅烷氧基)乙腈,用元素分析、IR和1HNMR进行了表征。经X-射线单晶衍射法测试表明,该化合物属单斜晶系,P21/c空间群,化学式为C25H27Fe2NOSi,独立衍射点10698个,可观察衍射点6552个(I>2s(I)),Mr=492.27,a=13.8197(13),b=20.0937(18),c=17.1269(16),b=105.114(2)埃琕=4591.4(7)?,Z=8,Dc=1.439g/cm3,(MoK?=1.332mm-1,F(000)=2064,最终偏离因子R=0.0410、wR,=0.0705。     

Synthesis and regioselective substitution of C-6 alkoxy derivatives of (S)-nicotine

Enantiopure (S)-6-alkoxynicotine derivatives have been synthesized in two steps from (S)-nicotine via (S)-6-iodonicotine. Deprotonation and substitution at the C-5 position of the pyridine ring of (S)-6-methoxynicotine were achieved using mesityllithium as the base at 0 °C. Conditions for the C-4 lithiation/substitution of (S)-6-isopropoxynicotine and (S)-5-chloro-6-methoxynicotine were also developed.     

Synthesis and characterization of zinc complexes and reactivity with primary phosphines

Zinc complexes of chelating monoanionic N-donors and neutral diphosphine ligands were synthesized by reaction of diethylzinc with 1,3-diketimine, diazabutadiene, and diphosphine ligand precursors. These complexes were reacted with primary phosphines in an attempt to solicit phosphine dehydrocoupling reactivity. In most cases, insoluble zinc-containing precipitates were formed and ligands were liberated. For the most sterically encumbered complex, (^DippL)ZnEt (3, ^DippL = [(2,6-ⁱPrC₆H₃)NC(CH₃)]₂CH^?), a product assigned as the zinc-phosphide (^DippL)ZnPHPh (6) was observed but could not be isolated as a pure compound. A new, less bulky β-diketiminate complex (^TolL)ZnEt (2, ^TolL = [(p-CH₃C₆H₄)NC(CH₃)]₂CH^?) was reacted with primary phosphines to give a precipitate and the bis(β-diketiminate)zinc complex (^TolL)₂Zn (5), an apparent product of comproportionation. (^MesAI)ZnEt (1, ^MesAI = MesNC(Me)(Et)C(Me) = NMes) and 2 were structurally characterized.     

Synthesis and characterization of zinc complexes and reactivity with primary phosphines

Zinc complexes of chelating monoanionic N-donors and neutral diphosphine ligands were synthesized by reaction of diethylzinc with 1,3-diketimine, diazabutadiene, and diphosphine ligand precursors. These complexes were reacted with primary phosphines in an attempt to solicit phosphine dehydrocoupling reactivity. In most cases, insoluble zinc-containing precipitates were formed and ligands were liberated. For the most sterically encumbered complex, (^DippL)ZnEt (3, ^DippL = [(2,6-ⁱPrC₆H₃)NC(CH₃)]₂CH⁻), a product assigned as the zinc-phosphide (^DippL)ZnPHPh (6) was observed but could not be isolated as a pure compound. A new, less bulky β-diketiminate complex (^TolL)ZnEt (2, ^TolL = [(p-CH₃C₆H₄)NC(CH₃)]₂CH⁻) was reacted with primary phosphines to give a precipitate and the bis(β-diketiminate)zinc complex (^TolL)₂Zn (5), an apparent product of comproportionation. (^MesAI)ZnEt (1, ^MesAI = MesNC(Me)(Et)C(Me) = NMes) and 2 were structurally characterized.     

Synthesis and characterization of perhalophenyltin derivatives. Study of their reactivity toward phosphine gold(I) chlorides

The (perhalophenyl)tin derivatives [SnR₄] (1-3) and [SnR₃Cl] (4-6) (R = C₆F₅, C₆F₃Cl₂, C₆Cl₅) were prepared from SnCl₄ and LiR or [SnR₄] in the appropriate molar ratio, while the dinuclear complexes [SnR₃]₂ (7-9) were obtained by treatment of [SnR₃Cl] with potassium under toluene reflux. Complexes 2, 6·0.5toluene and 7 were structurally characterized, the latter displaying a Sn-Sn bond of 2.808(7) Å, which indicates a strong tin-tin bond with covalent character in solid state. The hexaaryldistannanes 7-9 undergo transmetallation reactions with gold(I) derivatives, such as [AuCl(PPh₃)] or [(AuCl)₂(μ-dppm)], affording the neutral species [AuR(PPh₃)] (10-12) or [(AuR)₂(μ-dppm)] (13-15) or the ionic product [Au₃Cl₂(μ-dppm)₂][Sn(C₆F₅)₃Cl₂] (16). The crystal structures of 14·CH₂Cl₂, 15 and 16·2CH₂Cl₂ were determined by X-ray diffraction, the latter showing a Au₃ nearly equilateral triangular core in the cation with gold-gold contacts of 3.128(7) and 3.227(12) Å. The main difference between the molecular structures of 14·CH₂Cl₂ and 15 (both of them displaying intramolecular gold-gold contacts of 3.142(6) and 3.160(4) Å, respectively) is the presence of an intermolecular Au?Au interaction of 3.2126(8) Å in the case of the C₆F₃Cl₂ complex that gives rise to a tetranuclear unit.     

Synthesis and characterization of stable blue light‐emitting poly(spirobifluorene) derivatives containing alkoxy group

Polymers containing alkoxy‐substituted spirobifluorene have been prepared from nickel(0)‐mediated coupling or palladium‐catalyzed Suzuki coupling. The polymers were characterized using various spectroscopies, such as ¹H‐NMR, FT‐IR, and elemental analysis. The high glass transition temperature and high decomposition temperature suggested that the resulting polymers possessed a high thermal stability. The obtained polymers possessed weight average molecular weight of 4500–33,000 with polydispersity index of 1.1–1.9 and good solubility. The low onsets of the oxidation potential suggested that the polymers containing alkoxy substituted spirobifluorene possessed a good hole injection property. The photoluminescence and electroluminescence of the polymers containing alkoxy substituted spirobifluorene showed stable blue color by suppressing the excimer formation due to intermolecular interaction. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 2316–2324, 2005     

Layer arrangement in the structure of octakis-(trimethylsiloxy)octasilsesquioxane and dodecakis-(trimethylsiloxy)cyclohexasiloxane

Layers of [(CH₃)₃SiO]₈(SiO_1.5)₈ and [(CH₃)₃SiO]₁₂(SiO)₆ organosilicon compounds obtained by chemical vapor deposition were investigated by X-ray diffraction (DRON-RM4, R = 192 mm, CuK radiation) and Raman spectroscopy (Triplemate, SPEX). The layers were found to be ideally oriented polycrystalline films. The octakis-(trimethylsiloxy)octasilsesquioxane polycrystals are oriented in one crystallographic direction — [001], while the dodecakis-(trimethylsiloxy)cyclohexa-siloxane polycrystals are oriented in the and directions. Crystal structure analysis in these directions yielded the type of the planar lattice followed by the molecules and their orientation relative to the support.Original Russian Text Copyright © 2004 by S. A. Gromilov, T. V. Basova, D. Yu. Emelyanov, A. V. Kuzmin, and S. A. ProkhorovaTranslated from Zhurnal Strukturnoi Khimii, Vol. 45, No. 3, pp. 497–501, May–June 2004.     

Pyrrolothieno[1,4]diazepines: Synthesis of alkoxy derivatives

Reactivity of 2-(2-formyl-1H-pyrrol-1-yl)-3-thiophenecarbonitrile and of 2-(2-formyl-1H-pyrrol-1-yl)-3-thiophenecarboxamide was evaluated against various alkoxides. The synthetic pathways involved in these reactions which led to new 4- and 6-alkoxypyrrolothieno[1,4]diazepines are described.     

Synthesis and reactivity of hydrazido(2-) and imido derivatives of titanium(IV) tetratolylporphyrin

Titanium porphyrin hydrazido complexes (TTP)Ti = NNR2 (TTP = meso-tetra-p-tolylporphyrinato dianion; R = Me (1), Ph (2)) were synthesized by treatment of (TTP)TiCl2 with 1,1-disubstituted hydrazines H2NNR2 (R = Me, Ph) in the presence of piperdine. The nucleophilic character of the hydrazido moiety was demonstrated in the reactions of complexes 1 and 2 with p-chlorobenzaldehyde, which yielded the titanium oxo complex (TTP)-Ti = O and the respective hydrazones. Protonation of complexes 1 and 2 with phenol or water produced the 1,1-disubstituted hydrazine along with (TTP)Ti(OPh)2 or (TTP)Ti = O, respectively. Similar reactivity of p-chlorobenzaldehyde and phenol with (TTP)Ti = NiPr, 3, was observed. The reaction of complex 3 with nitrosobenzene cleanly formed the azo compound iPrN = NPh and the terminal oxo product (TTP)Ti = O.     

Synthesis of (-)-arctigenin derivatives and their anticancer activity

The natural dibenzylbutyrolactone type lignanolide (-)-arctigenin, which was prepared from fructus arctii, showed obvious anticancer activity. The synthesis of four new (-)-arctigenin derivatives and their anticancer bioactivities were examined. The structures of the four new synthetic derivatives were elucidated.