Transition Metal Complexes of P-rich Phosphanes and Silylphosphanes. VIII. Concerning the Different Tendencies of Silylated and Alkylated Phosphanes and Diphosphanes to Form Chromium Carbonyl Complexes The influence of the substituents Me3Si tBu and Me in phosphanes and diphosphanes on the formation of complex compounds with Cr(CO)5THF is investigated. tBu(Me3Si)P? P(SiMe3)2 1 and (tBu)2P? P(SiMe3)2 2, resp., react with Cr(CO)5THF 4 at ?18°C by coordinating Cr(CO)5 to the P(SiMe3)2 group to give tBu(Me3Si)P? PIV(SiMe3), · Cr(CO)5 1 a, tBu(Me3Si)PIV? PIV(SiMe3)2 · Cr(CO)4 1b and (tBu)2P? PIV(SiMe3)2 · Cr(CO)5 2a . In the reaction of 1 with 4 using a molar ratio of 1:2 at first 1 a is formed which reacts on to yield completely 1 b. In a mixture of the dissolved compounds (Me3Si)3P 5, (tBu)3P 6 and (tBu)3P? P(SiMe3)2 2 only 5 and 6 react with Cr(CO)5THF yielding (Me3Si)3P · Cr(CO)5 and (tBu)3P · Cr(CO)5, but 2 does not yet react. In a solution of (Me3Si)3P 5, P2Me4 7 and (Me3Si)2P? PMe2 3 only 5 and 7 react with Cr(CO)5THF (0.25 to 1.5 equivalents with respect to 3) to give (Me3Si)3P · Cr(CO)5, P2Me4 · Cr(CO)5 and P2Me4 · 2Cr(CO)5. The formation of complexes with Cr(CO)5THF of the phosphanes 5 and 6 is clearly favoured as compared to the silylated diphosphanes 2 and 3 (not to P2Me4); the PR2 groups (R = tBu, Me in 2 or 3 ) don't have a strong influence. 相似文献
Investigations of the Reaction between the [Lithium(trimethylsilyl)amido]-methyl-trimethyl-silylamino-silane Me(Me3SiNLi)(Me3SiNH)SiH and different Electrophiles The lithium silylamide Me(Me3SiNLi)(Me3SiNH)SiH 1 reacts with chlorotrimethylsilan in the nonpolar solvent n-hexane to the N-substitution product Me[(Me3Si)2N](Me3SiNH)SiH 2 and to the cyclodisilazane [Me(Me3SiNH)Si—N(SiMe3)]2 3 nearly in same amounts. The reaction of 1 with chlorotrimethylstannane gives besides small amounts of the cyclodisilazane 3 the N-substitution product Me[(Me3Si)(Me3Sn)N](Me3SiNH)SiH 4 . By the reaction of 1 with trimethylsilyltriflate the cyclodisilazane 3 is obtained as the main product. Furthermore 2 and the cyclodisilazane 5 are formed. Ethylbromide shows no reaction with 1 under the same conditions. These results indicate the existence of an equilibrium of the lithium silylamide 1 , the silanimine Me(Me3SiNH)Si?N(SiMe3) and lithium hydride. 相似文献
Transition Metal Complexes of P-rich Phosphanes and Silylphosphanes. X. The Influence of the Formation of Complex Compounds on the Reactivity of [(Me3Si)2P]2PH Whereas [(Me3Si)2P]2PH 1 by BuLi is attacked at the PH group to give [(Me3Si)2P]2PLi 2 , the related chromium carbonyl complex (Me3Si)PIV ? 2PIV(H) ? 3PIII(Si? Me3)2 · Cr(CO)4 3 with BuLi yields Li(Me3Si)1PIV ? 2PIV(H) ? 3PIII(SiMe3)2 · Cr(CO)4 4 by cleaving a Si? P bond at the chromium substituted 1P atom. Dissolved in ether, 4 is stable for a longer time, while under comparable conditions 2 forms Li3P7 which is not obtained from 4 . MeOH in 3 cleaves selectively the Me3Si groups from the complex substituted P atom yielding (Me3Si)(H)1PIV ? 2PIV(H) ? 3PIII(SiMe3)2 · Cr(CO)4 5 and HPIV ? 2PIV(H) ? 3PIII(SiMe3)2Cr(CO)4 6. 5 and 6 seem to be stable in contrast to the uncoordinated triphosphanes which are not known. 相似文献
Synthesis and Properties of Partially Silylated Tri- and Tetraphosphanes. Reaction of Lithiated Diphosphanes with Chlorophosphanes The reactions of Li(Me3Si)P? P(SiMe3)(CMe3) 1 , Li(Me3Si)P? P(CMe3)2 2 , and Li(Me3C)P? P(SiMe3)(CMe3) 3 with the chlorophosphanes P(SiMe3)(CMe3)Cl, P(CMe3)2Cl, or P(CMe3)Cl2 generate the triphosphanes [(Me3C)(Me3Si)P]2P(SiMe3) 4 , (Me3C)(Me3Si)P? P(SiMe3)? P(CMe3)2 6 , [(Me3C)2P]2P(SiMe3) 7 , and (Me3C)(Me3Si)P? P(SiMe3)? P(CMe3)Cl 8 . The triphosphane (Me3C)2P? P(SiMe3)? P(SiMe3)2 5 is not obtainable as easily. The access to 5 starts by reacting PCl3 with P(SiMe3)(CMe3)2, forming (Me3C)2 P? PCl2, which then with LiP(SiMe3)2 gives (Me3C)2 P? P(Cl)? P(SiMe3)2 11 . Treating 11 with LiCMe3 generates (Me3C)2P? P(H)? P(SiMe3)2 16 , which can be lithiated by LiBu to give (Me3C)2P? P(Li)? P(SiMe3)2 13 and after reacting with Me3SiCl, finally yields 5 . 8 is stable at ?70°C and undergoes cyclization to P3(SiMe3)(CMe3)2 in the course of warming to ambient temperature, while Me3SiCl is split off. 7 , reacting with MeOH, forms [(Me3C)2P]2PH. (Me3C)2P? P(Li)? P(SiMe3)2 18 , which can be obtained by the reaction of 5 with LiBu, decomposes forming (Me3C)2P? P(Li)(SiMe3), P(SiMe3)3, and LiP(SiMe3)2, in contrast to either (Me3C)2P? P(Li)? P(SiMe3)(CMe3) 19 or [(Me3C)2P]2PLi, which are stable in ether solutions. The Li phosphides 1 , 2 , and 3 with BrH2C? CH2Br form the n-tetraphosphanes (Me3C)(Me3Si)P? [P(SiMe3)]2? P(SiMe3)(CMe3) 23 , (Me3C)2P? [P(SiMe3)]2? P(CMe3)2 24 , and (Me3C)(Me3Si)P? [P(CMe3)]2? P(SiMe3)(CMe3) 25 , respectively. Li(Me3Si)P? P(SiMe3)2, likewise, generates (Me3Si)2P? [P(SiMe3)]2? P(SiMe3)2 26 . Just as the n-triphosphanes 4 , 5 , 6 , and 7 , the n-tetraphosphanes 23 , 24 , and 25 can be isolated as crystalline compounds. 23 , treated with LiBu, does nor form any stable n-tetraphosphides, whereas 24 yields (Me3C)2P? P(Li)? P(SiMe3)? P(CMe3)2, that is stable in ethers. With MeOH, 24 , forms crystals of (Me3C)2P? P(H)? P(SiMe3)? P(CMe3)2. 相似文献
Lithiated Siloxy-silylamino-silanes — Preparation and Reactions with Chlorodimethylsilane The siloxy-silylamino-silanes (Me3SiO)Me3–nSi(NHSiMe3)n ( 1 : n = 1, 2 : n = 2, 3 : n = 3) are obtained by coammonolysis of the chlorosiloxysilanes (Me3SiO)Me3–nSiCln (n = 1–3) with chlorotrimethylsilane. The reaction of 1, 2 , and 3 with n-butyllithium in appropriate molar ratio in n-hexane gives the siloxy-silylamido-silanes (Me3SiO)Me3–nSi(NLiSiMe3)n ( 4 : n = 1, 5 : n = 2, 6 : n = 3), which were spectroscopically characterized (IR, 1H-, 7Li-, 29Si-NMR) and allowed to react in solution (n-hexane, THF) with Me2Si(H)Cl. 4 reacts to the N-substitution product (Me3SiO)Me2SiN(SiMe3)SiMe2H 7, 5 to (Me3SiO)MeSi[N(SiMe3)SiMe2H](NHSiMe3) 8 , (Me3SiO)MeSi[N(SiMe3)SiMe2H]2 9 and to the cyclodisilazane 10. 6 gives in THF the cyclodisilazanes 11 : R = H; 12 : R = HMe2Si) and ( 13 , in n-hexane only 11 in small amounts. An amide solution of 2 with n-butyllithium in the molar ratio 1:1 in n-hexane leads to 8 (main product), 2 and 10; in THF 10 and 2 are obtained nearly in same amounts and 8 and 9 as byproducts. The amide solutions of 3 with n-butyllithium in the molar ratio 1:1 and 1:2, resp., show nearly the same behaviour in n-hexane and THF. In THF 3, 11 , and 12 and in n-hexane 3, 11, 12 , and (Me3SiO)Si[N(SiMe3)SiMe2H](NHSiMe3)2 14 are formed. 相似文献
N-Silylation and Si? O Bond Splitting at the Reaction of Lithiated Siloxy-silylamino-silanes with Chlorotrimethylsilane Lithiated Siloxy-silylamino-silanes were allowed to react in tetrahydrofurane (THF) and in n-octane (favoured) and n-hexane, resp., with chlorotrimethylsilane. The monoamide (Me3SiO)Me2Si(NLiSiMe3) gives in THF and in n-octane the N-substitution product (Me3SiO)Me2Si · [N(SiMe3)2] 1 , the diamide (Me3SiO)MeSi(NLiSiMe3)2 only in THF the N-substitution products (Me3SiO)MeSi[N(SiMe3)2]2 2 (main product) and (Me3SiO)MeSi[N(SiMe3)2](NHSiMe3) 3 . In n-octane the diamide reacts mainly under Si? O bond splitting. The cyclodisilazane [(Me3SiNH)MeSi? NSiMe3]2 6 is obtained as the main product. Byproducts are 2, 3 and the tris(trimethylsilylamino) substituted disilazane (Me3SiO)(Me3SiNH)MeSi? N · (SiMe3)? SiMe(NHSiMe3)2 7 . The triamide (Me3SiO)Si · (NLiSiMe3)3 reacts under Si? O and Si? N bond splitting in n-octane as well as in THF. The cyclodisilazanes [(Me3SiNH)2 · Si? NSiMe3]2 10 and ( 11 : R = Me3SiNH, 12 : R = (Me3Si)2N) are formed. in THF furthermore the N-substitution products (Me3SiO)Si[N(SiMe3)2] · (NHSiMe3)2 4 and (Me3SiO)Si[N(SiMe3)2]2(NHSiMe3) 5 . The Si? O bond splitting occurs in boiling n-octane also in absence of the chlorotrimethylsilane. An amide solution of (Me3SiO)MeSi(NHSiMe3)2 with n-butyllithium in the molar ratio 1 : 1 leads in n-octane and n-hexane to 6 and 7 , in THF to 3 . The amide solutions of (Me3SiO)Si · (NHSiMe3)3 with n-butyllithium the molar ratio 1 : 1 and 1 : 2 give in THF 4 and 5 , respectively. 相似文献
Abstract Our investigations to be presented here have their origin in a number of former results: The formation of [(Me3Si)2P]2SiMe2 [1] and its rearrangement to P4(SiMe2)6 (a molecule with adamantane structure) and P(SiMe3)3, the formation of P7(SiMe3)3 and of some cyclic phosphanes by the thermally induced rearrangement of [(Me3Si)2)P]2SiMe2 [3], and the formation of P7(SiMe3)3 by reacting P4 with Na/K-alloy and Me3SiCl. After finding LiP(SiMe3)2 to be such a versatile reagent we turned to elucidate synthesis and chemical behaviour of LiP[P(SiMe3)2]2. 相似文献
Concerning the Thermal Behaviour of Partially Silylated Tri- and Tetraphosphanes The influence of Me3Si- and Me3C-substituents in the compounds (Me3Si)P[P(SiMe3)(CMe3)]2 1 , (Me3C)2P-P(SiMe3)? P(SiMe3)2 2 , (Me3C)2P? P(SiMe3)? P(SiMe3)(CMe3) 3 , (Me3Si)P[P(CMe3)2]2 4 , (Me3C)(Me3Si)P? [P(SiMe3)]2? P (SiMe3)(CMe3) 5 , (Me3C)(Me3Si)P? [P(CMe3)]2? P (SiMe3)(CMe3) 6 and (Me3C)2P? [P(SiMe3)]2? P (CMe3)2 7 on their thermal stability as well as on the reactions that occur, when these compounds are exposed to higher temperatures, is investigated. The tetraphosphane 6 , bearing 4 Me3C and 2 Me3Si groups (the latter being located at the primary P atoms) hardly shows any changes, when it is exposed to 100°C in toluene (hermetically sealed ampoule) for several days, while the remaining compounds are found to rearrange significantly under similar conditions. Thus 1 [no (Me3C)2P-group] forms trans- P4 (SiMe3)2(CMe3)2 9 , while (Me3C)P(SiMe3)2 8 is being cleaved off, which can be understood easily, assuming the formation of the corresponding linear pentaphosphane (accompanied by the cleave-off of 8 ) and its subsequent cyclisation to 9 (again splitting off 8 ). 5 is found to form cyclophosphanes (tri-, penta-, hexa-), while (Me3C)P(SiMe3)2 and P(SiMe3)3 are being cleaved off. All of the remaining compounds mentioned [with (Me3C)2P-groups] finally yield, aside of P(SiMe3)3 and (Me3C)P(SiMe3)2, the cyclophosphanes P4[P(CMe3)2]4 11 and P3[P(CMe3)2]3 12 , which can be explained by the formation of the reactive intermediate (Me3C)2P? \documentclass{article}\pagestyle{empty}\begin{document}$\mathop {\rm P}\limits_ - ^ - $\end{document} ( which, however, has not been proven). 相似文献
Formation and Reaction of the Phosphanylidene-phosphorane (tBu)2P? P = PX(tBu)2 (X = Br, Cl) The formation of (tBu)2P? P = P(Br)tBu2 1 from [(tBu)2P]2PLi and BrH2C? CH2Br begins with an exchange of Li against Br and is then determined by the migration of Br from the secondary P atom in [(tBu)2P]2PBr 6 to the primary P in 1 . Similarly, (tBu)2P? P = PC1(tBu)2 2 is obtained starting from PCl3 and LiP(tBu)2. The formation of Phospanylidene—phosporane is not influenced by the choice o the halogene substituent, but the presence of the tBu groups is strongly required. (tBu)2P? P(Li)? P(SiMe3)2 e. g., yields (tBu)2P? P(br)? P(SiMe3)2 with BrH2C? CH2Br; however neither this nor (tBu)2P? P(Cl)? P(SiMe3)2 do rearrange to a Phosphanylidene-phosphorane. The F3C substituent could be neglected in this investigation as [(F3C)2P]2P? SiMe3 cannot be lithiated by means of BuLi. Compounds 1 and 2 display a charateristic temperature dependent behavior. While 1 at +20°C decomposes via the reactive intermediate (tBu)2P? P to from the cyclophosphanes P3[P(tBu)2]4, it gives crystals of [(tBu)2P]2P? p[P(tBu)2]2 at ?20°C (from a solution in toluene). Reacting 1 with tBuLi produces (tBu)2P? P = P(H)tBu2 20 and (tBu)2P? P(H)? P(tBu)2 14 . Initially, a transmetallation yield tBuBr and (tBu)2 P? P=Pli(tBu)2 21 ,then LiBr and isobutene are eliminated and 20 is formed which can rearrange to produce 14 . Without the elimination of isobutene, 1 react with nBuLi to give 21 witch can be trapped with Me3SiCl as (tBu)2P? P(tBu)2 23 . The main product in in this reaction is however [(tBu)2P]2P? nBu 22 . 相似文献
Investigations on the Formation of Silylated iso-Tetraphosphanes We investigated the formation of iso-tetraphosphanes by reacting [Me(Me3Si)P]2PCl 4 , Me(Me3Si)P? P(Cl)? P(SiMe3)2 8 , Me(Me3Si)P? P(Cl)? P(SiMe3)(CMe3) 9 , [Me(Me3Si)P]2PCl 20 , Me3C(Me3Si)P? P(Cl)? P(SiMe3)2 21 , and [MeC(Me3Si)P]2PCl 22 with LiP(SiMe3)Me 1 , LiP(SiMe3)2 2 , and LiP(SiMe3)CMe3 3 , respectively, to elucidate possible paths of synthesis, the influence of substituents (Me, SiMe3, CMe3) on the course of the reaction, and the properties of the iso-tetraphosphanes. These products are formed via a substitution reaction at the P2Cl group of the iso-triphosphanes. However, with an increasing number of SiMe3 groups in the triphosphane as well as in reactions with LiP(SiMe3)Me, cleaving and transmetallation reactions become more and more important. The phosphides 1,2, and 3 attack the PC1 group of 4 yielding the iso-tetraphosphanes P[P(SiMe3)Me]3 5, [Me(Me3Si)P]2P? P(SiMe3)2 6 and [Me(Me3Si)P]2P? P(SiMe3)CMe3 7. I n reactions With 8 and 9, LiP(SiMe3)Me causes bond cleavage and mainly leads to Me(Me3Si)P? P(Me)? P(SiMe3)2 13 and Me(Me3Si)P? (Me)? P(SiMe3)CMe3 16, resp., and to monophosphanes; minor products are [Me(SiMe3)P]2P? P(SiMe3)2 6 and [Me(Me2Si)P]2P? P(SiMe3)CMe2 7. LiP(SiMe3)2 2 and LiP(SiMe3)CMe2 3 with 8 and 9 give Me(Me3,Si)P? P[P(SiMe3)2]2 10, Me(Me2Si)P? P[P(SiMe3)CMe2]? P(SiMe3)2 11, and Me(Me3Si)P? P[P(SiMe3)CMe3]2 12 as favoured products. With 20, LiP(SiMe3)2 2 forms P[P(SiMe3)2]3 28. Bond cleavage products are obtained in reactions of 20 with 1 and 2, of 21 with 1, 2, and 3, and of 22 with 1 and 2. P[P(SiMe3)CMe3]3 23 is the main product in the reaction of 22 with LiP(SiMe3)CRle2 3. In the reactions of 22 with 1, 2, and 3 the cyclophosphanes P3(CMe3)2(SiMe3)25, P4[P(SiMe3)CMe3]2(CMe3)2 26, and P5(CMe3)4(SiMe3) 27 are produced. The formation of these rom- pounds begins with bond cleavage in a P- SiMe, group by means of the phosphides. The thermal stability of the iso-tetraphosphanes decreases with an increasing number of silyl groups in the molecule. At 20O°C compounds 5, 7, and 23 are crystals; also 6 is stable; however, 10, It, 12, and 28 decompose already. 相似文献
Organometallic Compounds of the Lanthanoids. 111. Synthesis and Characterization of Cationic Metallocene Complexes of the Lanthanoides. X-Ray Crystal Structure of [Cp Yb(THF)2][BPh4] Cationic organolanthanoide compounds [(C5H4R)2Sm(THF)2][BPh4] (R = tBu ( 1 ), SiMe3 ( 2 )), [PyrSm(THF)][BPh4] ( 3 ) (Pyr* = NC4H2tBu2-2,5), [CpLn(THF)2][BPh4] (Cp* = C5Me5; Ln = Y ( 4 ), Yb ( 5 )), and [(C5Me4Et)2 Ln(THF)2][BPh4] (Ln = Y ( 6 ), Sm ( 7 )) have been synthesized by oxidation of the divalent metallocenes [(C5H4R)2Sm(THF)2] (R = tBu, SiMe3), [PyrSm(THF)], [CpYb(THF), and [(C5Me4Et)2Sm(THF)] with Ag[BPh4] and by protolysis of the lanthanoide alkyls [CpYMe(THF)], [CpYbCH(SiMe3)2], and [(C5Me4Et)2LnCH(SiMe3)2] (Ln = Y, Sm) by [NEt3H][BPh4]. The 1H- and 13C-NMR spectra of the new compounds are discussed. 5 crystallizes in the space group P21/c with a = 10.604(7), b = 21.749(3), c = 19.124(4) Å, β = 96.47(4)°, Z = 4 and V = 4383(3) Å3 (R = 0.0291 for 8517 observed reflections with Fo ≥ 4σ (Fo). 相似文献
Formation of Organosilicon Compounds. 105. Reactions of (Cl3Si)2C?PMe2Cl with Silylphosphanes The reaction of (Cl3Si)2C?PMe2Cl 1 with MeP(SiMe3)2 proceeds at 130°C (15 hrs.), by cleavage of all Si? P bonds to compounds 2, 3, 4, 5 . The course of this reaction incorporates a number of stages of which the compounds (Cl3Si)2C? PMe2? P(Me)SiMe3, (Cl3Si)2C?PMe2? PMe? P(Me)SiMe3 and ClP(Me)SiMe3 are important and are yet to be isolated. The reaction of (Cl3Si)2C?PMe2Cl with LiP(SiMe2)2 produces compound 2 as well as p2(SiMe3)4 and P(SiMe3)3. The formation of 2 can be explained by the initial formation of the intermediate (Cl3Si)2C?PMe2? P(SiMe2)2 with reacts with 1 to produce 2 and (ClP(SiMe)3)2. The formation of P2(SiMe3)4 is also explained by the reaction of ClP(SiMe3)2 with LiP(SiMe3)4. The reaction of (Cl3Si)2C?PMe2C(H)PMe2 at 130°C/15–20 hrs. is related to the formation of (Me3Si)2C(H)Pme2 from corresponding Si-methylated phosphorylides with the exception that, at 0°C, this reaction goes to completion within a few minutes. 相似文献
On Tris[(trialkylphosphine)gold(I)]oxonium Tetrafluoroborates and Tris[(triphenylphosphine)gold(I)]sulfonium Tetrafluoroborate [Et3PAu]+BF, obtained from Et3PAuCl and AgBF4 in tetrahydrofuran, reacts with KOH (molar ratio 3:1) to give the oxonium salt [(Et3P)Au]3O+BF ( 1 ). The homologous [t(Bu3P)Au]3O+BF ( 2 ) is generated similarly from tBu3PAuCl and Ag2O in the presence of NaBF4 in THF. The composition and identity of these two first tris[(tri alkyl phosphine)gold(I)]oxonium salts have been confirmed by analytical and spectroscopic data. The compounds are useful aurating agents. From the corresponding triphenylphosphine complex and (Me3Si)2S quantitative yields of the sulfonium salt [(Ph3P)Au]3S+BF ( 3 ) are obtained. Its crystal structure features monomeric cations, and in these small Au? S? Au angles indicate significant metal-metal bonding. 相似文献
The Reaction Behaviour of Lithiated Aminosilanes RR′Si(H)N(Li)SiMe3 The bis(trimethylsilyl)aminosubstituted silances RR′Si(H)N(SiMe3)2 11 – 16 (R,R′ = Me, Me3SiNH, (Me3Si)2N) are obtained by the reaction of the lithium silylamides RR′Si(H)N(Li)SiMe3 1 – 10 (R,R′ = Me3SiNLi, Me, Me3SiNH, (M3Si)2N) with chlorotrimethylsilane in the polar solvent tetrahydrofurane (THF). In the reaction of the lithium silylamides [(Me3Si)2N]2(Me3SiNLi)SiH 10 with chlorotrimethylsilane in THF the rearranged product 1,1,3-tris[bis(trimethylsilyl)amino]-3-methyl-1,3-disila-butane [(Me3Si)2N]2Si(H)CH2SiMe2N(SiMe3)2 17 is formed. The reaction of the lithium silyamides RR′ Si(H)N(Li)SiMe3 1 – 3 (1: R = R′ = Me; 2: R = Me, R′ = Me3SiNH; 3: R = Me, R′ = Me3SiNLi) with chlorotrimethylsilane in the nonpolar solvent n-hexane gives the cyclodisilazanes [RR′ Si? NSiMe3]2 18 – 22 (R = Me, Me3SiNH, (Me3Si)2N; R′ = Me, Me3SiNH, (Me3Si)2N, N(SiMe3)Si · Me(NHSiMe3)2) and trimethylsilane. The lithium silylamides 4 , 5 , 6 , 9 , 10 (4: R = R′ = Me3SiNH; 5: R = Me3SiNH, R′ = Me3SiNLi; 6: R = R′ = Me3SiNLi; 9: R = (Me3Si)2N, R ′ = Me3SiNLi; 10: R = R′ = (Me3Si)2N) shows with chlorotrimethylsilane in n-hexane no reaction. The crystal structure of 17 and 21 are reported. 相似文献
Formation and Reactions of Silylated Triphosphanes Silylated triphosphanes, containing primary P(SiMe3)2, P(SiMe3)CMe3, or P(SiMe3) Me endgroups and secondary =PCl, =PH, =PLi, =PSiMe3, or =PCMe3 groups were prepared by firstly reacting PCl3 with P(SiMe3)2R (R = CMe3, Me) and subsequently by substituting the diphosphanes R(Me3Si)P—PCl2 with LiP(SiMe3)R′ (R′ = SiMe3, CMe3, Me) Such triphosphanes, containing both =PCI and =PSiMe3 groups decompose at room temperature. Stable products, however, were isolated after immediately derivating the 2-chloro-triphosphanes at ? 78°C with LiCMe3. Among the competing reactions:
1 =PC1 substitution yielding the =PCMe, group.
2 Cl/Li exchange forming the phosphides =PLi and Ne,CCl,
3 consecutive reactions of the phosphides, producing the =PH derivatives -L iso-butene + LiCl with Me3CCI, or the =PSiMe3 derivatives with Me3SiCl, respectively,
the formation of secondary =PI1 groups is favored by sterically requiring groups, –SiMe, or -CMe 3 , at the primary P atoms; whereas Me groups enable the substitution of the secondary P atoms by SiMe 3 or CMe 3 . Pure 2-Li-triphosphides were readily obtained from the =PH derivatives with LiBu in n-pentane. In ethers these phosphides eliminate (Me 3 Si) 3 P, LiP(SiMe 3 ) 2 , or (Me 3 C)P(SiMe 3 ) 2 , yielding P-rich compounds in a complex reaction sequence. For instance, Li 3 P 7 is generated as main-product from [(Me 3 Si) 2 P] 2 PLi, the cyclotetraphosphane P 4 (CMe 3 ) 3 SiMe 3 from (Me 3 Si) 2 P-P(Li)-P(SiMe 3 )CMe 3 , and the cyclic pentaphosphide LiP 5 (CMe 3 ) 4 from [(Me 3 C)(Me 3 Si)P] 2 PLi. 相似文献
Transition Metal Phosphido Complexes. XVII. Reactions of Silylphosphine Derivatives with (R3P)2PtCl2 (R ? Et, Ph) In reactions of (Et3P)2PtCl2 1a with LiP(SiMe3)2 at low temperatures the substitution products (Et3P)2Pt[P(SiMe3)2]Cl 2a and (Et3P)2Pt[P(SiMe3)2]2 3a are formed first. At ambient temperature from 3a P(SiMe3)3 and PEt3 are split off yielding a mixture of the diphosphene complex (Et3P)2Pt[η2-(PSiMe3)2] 4a and the phosphido-bridged platinum(I) complex [Et3PPtP(SiMe3)2]2(Pt? Pt) 5a . Heating 2a to 80°C in solution gives the P2-complex [(Et3P)2Pt]2P2 6a . 4a and 6a are also obtained reacting 1a with [(Me3Si)2P]2. From 1a and [Me3Si(Me3C)P]2 the diphosphene complex (Et3P)2Pt[η2-(PCMe3)2] 8a is available. In the reaction of 1a with (Me3Si)2P? P(CMe3)SiMe3 the formation of the asymmetric diphosphene complex (Et3P)2Pt[η2-Me3SiP?PCMe3] 9a can be proved n.m.r. spectroscopically. Analogous reactions of (Ph3P)2PtCl2 1b with LiP(SiMe3)2, and with [Me3Si(Me3C)P]2 are much more difficult to survey. The complexes (Ph3P)2Pt[η2-(PSiMe3)2] 4b , [(Ph3P)2Pt]2P2 6b , and (Ph3P)2Pt[η2-(PCMe3)2] 8b are formed in n.m.r. spectroscopically detectable amounts but could not be isolated as pure compounds. N.m.r. and mass spectral data are reported. 相似文献
Formation of Organosilicon Compounds. 108 [1]. Thermally Induced Reactions of Amino-Substituted Disilanes Thermally induced reactions of amino-substituted disilanes yield Si rich silanes. At 300°C, Me3Si? SiMe2? NMeH 1 yields Me3Si? NMeH 2 and Me3Si? (SiMe2)2-NMeH 3 in a ratio 1 : 2 : 3 = 1,6 : 1 : 1, whereas Me3Si? SiMe2? N(iPr)H 4 at 350°C yields Me3Si? N(iPr)H 5 , Me3Si? (SiMe2)2-N(iPr)H 6 and Me3Si? (SiMe2)3? N(iPr)H 7 in a ratio of 4 : 6 : 7 = 0.8 : 1.0 : 0.6. Me3Si? SiMe2? NMe2 8 at 300°C (72 h) yields Me3Si? NMe2 9 and Me3Si-(SiMe2)2-NMe2 10 in a ratio of 9 : 8 : 10 = 1 : 0.22 : 0.44 The thermal stability of these disilanes is determined by the sterical requirements of the amino substituents NMeH < NMe2 < N(iPr)H. The introduction of a second NMe2 group decreases the stability and favours the formation of Si rich silanes. Such, Me2N? (SiMe2)2? NMe2 11 already at 250°C (2 h) yields Me2N? SiMe2? NMe2 12 , Me2N? (SiMe2)2? NMe2 13 and Me2N? (SiMe2)4? NMe2 14 in a ratio of 11 : 13 : 14 = 0.3 : 0.9 : 1.0. The reactions can be understood as insertions of thermally produced dimethylsilylene into the Si? N bond of the disilanes. This process is strongly favoured as compared to the trapping reactions with Ph? C?C? Ph or Et3SiH. The mentioned reactions correspond closely to those of the methoxy-disilanes[2]. However (MeN? SiMe2? SiMe2)2 15 , obtained from HMeN? (SiMe2)2? NMeH by condensation [3], at 400°C suffers a ring contraction to octymethyl-1,3-diaza-2,4,5-trisilacyclopentane (69 weight %), and yields also some solid residue, the composition of which corresponds to Si3C7NH21. 相似文献
The compound (Me3Si)3CSiPh2F loses Me3SiF under reflux or on passage through a tube at 450°C to give three products, A, B, and C, in approximately 20/20/60 ratio. Products A and B, which are solids, were shown by X-ray crystallographic analysis to be the diastereoisomeric forms of 1-dimethylsila-2-trimethylsilyl-3-[(methyl)(phenyl)sila]indane. From its mass and 1H NMR spectra, C (a liquid) was tentatively identified as 1,3-bis(dimethylsila)-2-[(dimethyl)(phenyl)silyl]indane. All three products are isomers of the sila-olefin (Me3Si)2CSiPh2, and it is suggested that the latter is first formed by loss of Me3SiF from (MeSi)3CSiPh2F, and the equilibrium (Me3Si)2CSiPh2 ? (Me3Si)(Ph2MeSi)CSiMe2 ? (Me3Si)(PhMe2Si)CSiMePh ? (Me2PhSi)2CSiMe2 is then rapidly established; internal cyclizations involving addition of aryl CH bonds across SiC bonds then occur to give the observed products. Consistent with this is the observation that a mixture of silicon alkoxides, thought to be (Me3Si)2CHSiPh2OMe and its isomers (which would be formed by addition of methanol across the SiC bonds of the four sila-olefins) is produced when methanol is passed through the hot tube with the (Me3Si)3CSiPh2F.Full structural details are given for compounds A and B. Some features of interest are: (a) the conformation of the 5-membered ring is different in the two diastereoisomers; (b) the exocyclic SiCSiMe3 bond angles, of ca. 120° are unusually large; and (c) there is a little distortion of the fused benzene ring, which is attributed to the effect of silicon substituents on the hybridization of carbon atoms to which they are attached. 相似文献
Diamino-di-tert-butylsilanes - Building Blocks for Cyclic (SiN)2, (SiNBN)2, (SiN2Sn), and Spirocyclic (SiN2)2Si, (SiN2Sn)2S Compounds The aminochlorosilanes (Me3C)2SiClNHR ( 1 : R?H, 2 : R?Me) are obtained by the ammonolysis ( 1 ) respectively aminolysis ( 2 ) of di-tert-butyldichlorosilane in the n-hexane. The dilithium derivative of diamino-di-tert-butylsilane reacts with FSiMe2R′ ( 3 : R′?Me, 4 : R′?F) in a molar ratio 1 : 2 to give the 1,3,5-trisilazanes 3 and 4 , (Me3C)2SiNHSiMe2R′, in a molar ratio 1 : 1 with F3SiN(SiMe3)2 to give the 1,3-diaza-2,4-disilacyclobutane 5 , (Me3C)2Si(NH)2SiFN(SiMe3)2, and with F2BN(SiMe3)2 to give the 1,3,5,7-tetraaza-2,6-dibora-4,8-disilacyclooctane 6 , [(Me3C)2SiNH-BN(SiMe3)2-NH]2. The dilithium derivative of di-tert-butyl-bis(methylamino)silane reacts with SiF4 with formation of the 1,3,5-trisilazane 7 , (Me3C)2Si(NMeSiF3)2, and the spirocycic compound 8 , [(Me3C)2Si(NMe)2]2Si, with SnCl2 the cyclosilazane 9 , (Me3C)2SiNMe2 is obtained. The dilithium derivative of 3 reacts with SnCl2 to give the cyclo-1,3-diaza-2-sila-4-stannylen 10 , (Me3C)2Si(NSiMe3)2Sn. The oxidation of 10 with elemental sulfur leads to the formation of the spirocyclus 11 , [(Me3C)2Si(NSiMe3)2SnS]2. 相似文献
Formation of the Cyclotetraphosphanes cis- und trans-P4(SiMe3)2(CMe3)2 in the Reaction of (Me3C)PCl2 with LiP(SiMe3)2 · 2 THF The mechanism of the reaction of (Me3C)PCl2 1 with LiP(SiMe3)2 · 2 THF 2 was investigated. With a mole ration of 1:1 at ?60°C quantitatively (Me3C)(Cl)P? P(SiMe3)2 3 is formed. This compound eliminates Me3SiCl on warming to 20°C, yielding Me3Si? P?P? CMe3 4 (can be trapped using 2,3-dimethyl-1,3-butadiene in a 4+2 cycloaddition), which dimerizes to produce the cyclotetraphosphanes cis-P4(SiMe3)2(CMe3)2 5 and trans-P4(SiMe3)2(CMe3)2 6 . Also with a mole ratio of 1:2 initially 3 is formed which remarkably slower reacts on to give [(Me3Si)2P]P2P? CMe3 8 . Remaining LiP(SiMe3)2 cleaves one Si? P bond of 8 producing (Me3)2P? P(CMe3)? P(SiMe3)2Li. Via a condensation to the pentaphosphide 10 and an elimination of LiP(SiMe3)2 from this intermediate, eventually trans-P4(SiMe3)2(CMe3)2 6 is obtained as the exclusive cyclotetra-phosphane product. 相似文献
