Preparation and Reactions of Silylated Diphosphanes The preparation of previously not available silylated diphosphanes is reported, i. e. the compounds (Me3Si)2P? P(SiMe3)(CMe3) 1 , (Me3Si)2P? P(CMe3)2 2 and (CMe3)2P? P(SiMe3)(CMe3) 4 as well as of the respective PH containing derivatives and Li phosphides thereof. The reaction of 1 with MeOH leads to (Me3Si)2P? P(CMe3) H 6 , while 4 generates (Me3C)2P? P(CMe3) H 7 , and finally 3 gives access to (Me3C)(Me3Si)P? P(CMe3) H 8 . LiBu on the other hand forms the Li phosphides Li(Me3Si)P? P(SiMe3)(CMe3) 10 (through 1 ), Li(Me3Si)P? P(CMe3)2 11 (through 2 ), Li(Me3C)P? P(SiMe3)(CMe3) 12 (through 3 ), and Li(Me3C)P? P(CMe3)2 13 (through 4 ), the latter being more easily accessible through the reaction of H(Me3C)P? P(CMe3)2 with LiBu. The introduction of one single CMe3 substituent into 1 is sufficient to obtain the Li phosphide 10 , which is stable in ethers, as opposed to the corresponding Li Phosphide of the persilylated diphosphane. 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
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
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
Extension of the Chain Length of P2(SiMe3)4 by Reaction with LiBu The first steps of the reaction of P2(SiMe3)4 1 with LiBu in THF, which finally yields Li3P7 among other P-rich phosphides while P(SiMe3)3 and LiP(SiMe3)2 are simultaneously split off, were investigated by means of 31P-NMR spectroscopy. At ?20°C first of all one Si? P bond is cleaved generating Li(Me3Si)P? P(SiMe3)2 2 as well as BuSiMe3. Subsequently 2 forms Li(Me3Si)P? P(SiMe3)? P(SiMe3)2 5 and LiP(SiMe3)2 4 in equimolar ratios. This clearly demonstrates that both compounds are generated in one single reaction step. This behaviour is caused by the different basicity of the respective P-atoms in 2 , which necessarily results in a multicentered mechanism. 相似文献
Formation and Structure of the Cyclophosphanes P4(CMe3)2[P(CMe3)2]2 and P4(SiMe3)2[P(CMe3)2]2 n-Triphosphanes showing a SiMe3 and a Cl substituent at the atoms P1 and P2, like (Me3C)2P? P(SiMe3)? P(CMe3)Cl 3 or (Me3C)2P? P(Cl)? P(SiMe3)2 4 are stable only at temperatures below ?30°C. Above this temperature these compounds lose Me3SiCl, thus forming cyclotetraphosphanes, P4(CMe3)2[P(CMe3)2]2 1 out of 3 , P4(SiMe3)2[P(SiMe3)2]2 2a (cis) and 2b (trans) out of 4 . The formation of 1 proceeds via (Me3C)2P? P?PCMe3 5 as intermediate compound, which after addition to cyclopentadiene to give the Diels-Alder-adduct 6 (exo and endo isomers) was isolated. 6 generates 5 , which then forms the dimer compound 1 . Likewise (Me3C)2P? P?P-SiMe3 8 (as proven by the adduct 7 ) is formed out of 4 , leading to 2a (cis) and 2b (trans). Compound 1 is also formed out of the iso-tetraphosphane P[P(CMe3)2]2[P(CMe3)Cl] 9 , which loses P(CMe3)2Cl when warmed to a temperature of 20°C. 1 crystallizes monoclinically in the space group P21/a (no. 14); a = 1762.0(15) pm; b = 1687.2(18) pm; c = 1170.5(9) pm; β = 109.18(5)° and Z = 4 formula units in the elementary cell. The molecule possesses E conformation. The central four-membered ring is puckered (approx. symmetry 4 2m; dihedral angle 47.4°), thus bringing the substituents into a quasi equatorial position and the nonbonding electron pairs into a quasi axial position. The bond lengths in the four-membered ring of 1 (d (P? P) = 222.9 pm) are only slightly longer than the exocyclic bonds (221.8 pm). The endocyclic bond angles \documentclass{article}\pagestyle{empty}\begin{document}$ \bar \beta $\end{document}(P/P/P) are 85.0°, the torsion angles are ±33° and d (P? C) = 189.7 pm. 相似文献
Formation of Organosilicon Compounds. 103. Formation and Structure of cis and trans 2,4-Dichloro-2,4-bis(trimethylsilyl)-1,1,3,3-tetramethyl-1,3-disilacyclobutane The reaction of Me3Si? CCl2? SiMe2Cl with LiBu in THF yields 1,1,3,3-Tetramethyl-2,4-bis(trimethylsilyl) 1,3-disilabicyclo[1.1.0]butane. The product of the first reaction stage is Me3Si? CCl(Li)-SiMe2Cl. The 1,3-Disilacyclobutane 2 and 3 were isolated, when Me3Si? CCl2? SiMe2Cl was treated with LiBu in Et2O. This way the proof is given that 2 and 3 are intermediates of the formation of product 1 . The further products are 4 and 5 (CCl in 2 and 3 substituted by CH) and Me3Si? CH2? C(SiMeCl)2SiMe3. 2 crystallizes orthorhombically in the space group Fdd 2 (no. 43) with a = 2149.1 pm, b = 2229.2 pm, c = 1763.6 pm and Z = 16 molecules per cell. The central ring of disilacyclobutane is slightly folded (17.9°). The configuration of the C-Atoms in this four membered ring gets closer to a sp2 configuration built up by three Si? C bonds. The Cl-atoms approximately have orthogonal positions to these CSi3 arrangements. The extension of the C? Cl bonds (184.6 pm) and the mutual approximations of the Cl-atoms in the cis-position indicate a high reactivity of the molecule. 相似文献
Treatment of [Li(H2Ga{CH(SiMe3)2}2)] ? 2 OEt2 ( 1? 2 OEt2) with two equivalents of tert‐butyl hydrogen peroxide, H‐O‐O‐CMe3, afforded the organogallium peroxide [({(Me3Si)2HC}2Ga(OH)(OOCMe3)Li)2] ( 3 ), which possesses oxidizing peroxo groups in close proximity to reducing Ga? C bonds. The lithium atoms of the dimeric formula units are coordinated by both oxygen atoms of the peroxides and by two hydroxo groups. The cleavage of the Ga? C bond was not observed, even when an excess of H‐O‐O‐CMe3 was applied. Instead, the adduct [{(Me3Si)2HC}2Ga(OH)(OOCMe3)2Li2(HOOCMe3)] ( 4 ) was isolated, which has an intact H‐O‐O‐CMe3 molecule terminally attached to lithium. A similar structural motif was found for the compound [(LiOOCMe3)2(HOOCMe3)2] ( 5 ). The trihydrido gallanate [Li(H3Ga? {CH(SiMe3)2})] ? OEt2 ( 2 ) yielded the unique peroxide [({(Me3Si)2HC}? Ga(H)(OOCMe3)2Li)2] ( 6 ) under similar conditions that possesses Ga? C and even more reactive Ga? H bonds beside peroxo groups. It decomposed at room temperature by the insertion of oxygen atoms into the Ga? H bonds and the formation of [({(Me3Si)2HC}? Ga(OH)(OCMe3)(OOCMe3)Li)2] ( 7 ), which was isolated in a low yield. Further decomposition gave the complete degradation of all peroxo groups with the formation of a relatively complicated Li4Ga4O8 cage ( 8 ). 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
Crystal Structure of Bis[lithium-tris(trimethylsilyl)hydrazide] and Reactions with Fluoroboranes, -silanes, and -phospanes Tris(trimethylsilyl)hydrazine reacts with n-butyllithium in n-hexane to give the lithium-derivative 1 . The reaction of 1 with SiF4, PhSiF3, BF3 · OEt2, F2BN(SiMe3)2 and PF3 leads to the substitution products 2–6 . The 1,2-diaza-3-bora-5-silacyclopentane 7 is formed by heating (Me3Si)2N? N(SiMe3)(BFNSiMe3)2 ( 5 ) at 250°C. In the reaction of (Me3Si)2N? N(SiMe3)PF2 ( 6 ) with lithiated tert.-butyl(trimethylsilyl)amine the hydrazino-iminophosphene (Me3Si)2N? N = P? N(SiMe3)(CMe3) ( 8 ) is obtained. In the molar ratio 2:1 1 reacts with SiF4 and BF3 · OEt2 to give bis[tris(trimethylsilyl)hydrazino]silane 9 and -borane 10 . 相似文献
On the Reactivity of (η5-C5Me5)(CO)2FeP(SiMe3)2 Toward P-Chloromethylene phosphanes The reaction of (η5-C5Me5)(CO)2FeP(SiMe3)2 ( 2 ) with three equivalents of Cl? P?C(SiMe3)2 ( 3a ) afforded the 3-methanediyl-1,3,5,6-tetraphosphabicyclo[3.1.0]hex-2-ene (η5-C5Me5)(CO)2Fe? ( 6a ). In contrast, 2 reacts with two equivalents of Cl? P?C(Ph)SiMe3 ( 3b ) to give the thermolabile (η5-C5Me5) · (CO)2Fe? P[P?C(Ph)SiMe3]2 ( 4b ) which decomposed during the reaction with further 3b. 4 b was also obtained from (η5-C5Me5)(CO)2Fe? P(SiMe3)? P?C(SiMe3)2 ( 1a ) and two equivalents of 3b . 相似文献
Migration of the Cl substituent takes place when (Me3Si)2C(SiMe2Cl)(SiEt2I) or (Me3Si)2C(SiEt2Cl)(SiMe2I) reacts with AgBF4, the product in each being a mixture of (Me3Si)2C(SiEt2Cl)(SiMe2F) and (Me3Si)2C(SiEt2F)(SiMe2Cl), and analogous migration of N3 occurs in the corresponding reaction of (Me3Si)2C-(SiEt2N3)(SiMe2Br). Anchimeric assistance by the N3 group facilitates the solvolysis of (Me3Si)2C(SiMe2N3)(SiMe2Br). 相似文献
Transition Metal-substituted Acylphosphanes and Phosphaalkenes. 22. Insertions of Hexafluoroacetone into the PX-Bond of Metallophosphanes (η5-C5Me5)(CO)2M? PX2 (M = Fe, Ru; X = Me3Si, Cl). Structure Determination of (η5-C5Me5)(CO)2Fe? P(SiMe3)C(CF3)2(OSiMe3) Reaction of the metallophosphanes (η5-C5Me5)(CO)2M? P(SiMe3)2 ( 1a : M = Fe; 1b : M = Ru) with hexafluoroacetone (HFA) afforded the complexes (η5-C5Me5)(CO)2M? P(SiMe3)C(CF3)2(OSiMe3) ( 2a, b ). The attempted synthesis of a metallophosphaalkene from 2a by thermal elimination of hexamethyldisiloxane failed. The acid catalyzed hydrolysis of 2a afforded compound (η5-C5Me5) · (CO)2Fe? P(H)C(CF3)2(OSiMe3) ( 3 ). Hexafluoracetone and (η5-C5Me5)(CO)2Fe? PCl2 ( 4 ) under-went reaction to give the metallochlorophosphan (η5-C5Me5) · (CO)2Fe? P(Cl)? O? C(CF3)2Cl ( 5 ). Constitutions and configurations of the compounds ( 2–5 ) were established by elemental analyses and spectroscopic data (IR, 1H-, 13C, 19F-, 29Si-, 31P-NMR, MS). The molecular structure of 2a was determined by x-ray diffraction analysis. 相似文献
Organo-Cobalt(II) Phosphorane Iminato Complexes with Heterocubane Structures. Crystal Structures of [CoBr(NPR3)]4 with R = Me, Et, [Co(C≡C–CMe3)(NPMe3)]4, and [Co(C≡C–SiMe3)(NPEt3)]4 The phosphorane iminato complexes [CoBr(NPR3)]4, which are accessible by reaction of CoBr2 with the silylated phosphorane imines Me3SiNPR3 (R = Me, Et) in the melt at 180 °C and in the presence of KF, can be transformed into the alkynyl complexes [Co(C≡C–CMe3) · (NPMe3)]4 and [Co(C≡C–SiMe3)(NPEt3)]4 on obtaining the heterocubane structures, when caused to react with the lithium organic reagents LiC≡C–CMe3 and LiC≡C–SiMe3 in THF at 0 °C. According to the crystal structure analyses all four of the compounds form heterocubane structures with only slightly distorted Co4N4 cubic structures. 相似文献
Transition Metal Complexes of P-rich Phosphanes and Silylphosphanes. IX. Chromium Carbonyl Complexes of Silylated and Alkylated Triphosphanes . To investigate the influence of the substituents on the formation of complex compounds of triphosphanes several derivatives were synthesized which differ in the number and position of the Me3Si and tBu groups at the primary P atoms and which bear H, Me3Si, Me of Ph groups at the secondary P atom. These are [(Me3Si)2P]2PH 1 , [(Me3Si)2P]2P(SiMe3) 2 , (MeSi)(tBu)P? P(H)? P(SiMe3)2 3 , (tBu)2P? P(SiMe3)? P(tBu)(SiMe3) 4 , [(tBu)2P]2PH 5 , [(tBu)2P]2P(SiMe3) 6 , [(Me3Si)2P]2PMe 7 , [(Me3Si)2P]2P(Ph) 8 . When reacting these compounds with Cr(CO)5THF 9 the following groups of products are obtained: Compounds 1, 3, 5, 7 and 8 at first yield products of group A and react on to B; however this second step is not important for 7 and even less for 8. Compounds 2, 4 and 6 bearing a Me3Si group at the secondary P atom yield C, but their reactivity is strongly reduced and they tend to give byproducts. Using a molar ratio of triphosphane: Cr(CO),THF 9 = 1 : 2 A forms also D in addition to B . Further reactions may occur from A and B , e. g., at 50°C 1 b ( B ) decomposes to 1 and lc (E). With Cr(CO),NBD the compounds 1, 5, 7 and 8 form products of groups E and F. At ?18°C 7 forms 7c (E) which rearranges at 75°C to 7d (F). The compounds are characterized by 31P and 1H NMR spectra, mass spectra and elemental analysis. 相似文献
Reactions of Lithium Hydridosilylamides RR′(H)Si–N(Li)R″ with Chlorotrimethylsilane in Tetrahydrofuran and Nonpolar Solvents: N‐Silylation and/or Formation of Cyclodisilazanes The lithiumhydridosilylamides RR′(H)Si–N(Li)R″ ( 2 a : R = R′ = CHMe2, R″ = SiMe3; 2 b : R = R′ = Ph, R″ = SiMe3; 2 c : R = R′ = CMe3, R″ = SiMe3; 2 d : R = R′ = R″ = CMe3; 2 e : R = Me, R′ = Si(SiMe3)3, R″ = CMe3; 2 f – 2 h : R = R′ = Me, f : R″ = 2,4,6‐Me3C6H2, g : R″ = SiH(CHMe2)2, h : R″ = SiH(CMe3)2; 2 i : R = R′ = CMe3, R″ = SiH(CMe3)2) were prepared by reaction of the corresponding hydridosilylamines RR′(H)Si–NHR″ 2 a – 2 i with n‐butyllithium in equimolar ratio in n‐hexane. The unknown amines 1 e – 1 i and amides 2 f – 2 i have been characterized spectroscopically. The wave numbers of the Si–H stretching vibrations and 29Si–1H coupling constants of the amides are less than of the analogous amines. This indicates a higher hydride character for the hydrogen atom of the Si–H group in the amide in comparison to the amines. The 29Si‐NMR chemical shifts lie in the amides at higher field than in the amines. The amides 2 a – 2 c and 2 e – 2 g react with chlorotrimethylsilane in THF to give the corresponding N‐silylation products RR′(H)Si–N(SiMe3)R″ ( 3 a – 3 c , 3 e – 3 g ) in good yields. In the reaction of 2 i with chlorotrimethylsilane in molar ratio 1 : 2,33 in THF hydrogen‐chlorine exchange takes place and after hydrolytic work up of the reaction mixture [(Me3C)2(Cl)Si]2NH ( 5 a ) is obtained. The reaction of the amides 2 a – 2 c , 2 f and 2 g with chlorotrimethylsilane in m(p)‐xylene and/or n‐hexane affords mixtures of N‐substitution products RR′(H)Si–N(SiMe3)R″ ( 3 a – 3 c , 3 f , 3 g ) and cyclodisilazanes [RR′Si–NR″]2 ( 6 a – 6 c , 6 f , 6 g ) as the main products. In case of the reaction of 2 h the cyclodisilazane 6 h was obtained only. 2 c – 2 e show a very low reactivity toward chlorotrimetyhlsilane in m‐xylene and toluene resp.. In contrast to Me3SiCl the reactivity of 2 d toward Me3SiOSO2CF3 and Me2(H)SiCl is significant higher. 2 d react with Me3SiOSO2CF3 and Me2(H)SiCl in n‐hexane under N‐silylation to give RR′(H)Si–N(SiMe3)R″ ( 3 d ) and RR′(H)Si–N(SiHMe2)R″ ( 3 d ′) resp. The crystal structures of [Me2Si–NSiMe3]2 ( I ) ( 6 f , 6 g and 6 h ) have been determined. 相似文献
Formation of Cyclic Silylphosphanes. Reaction of Li-Phosphides with R2SiCl2 (R? Me, Et, t-Bu) The reaction of Me2SiCl2 with Li-phosphides (mixture of LiPH2, Li2PH) leads to the formation of Me2Si(PH2)Cl 1 , Me2Si(PH2)2 2 , H2P? SiMe2? PH? SiMe2Cl 3 , (H2P? SiMe2)2PH 4 , (HP? SiMe2)3 6 , 5 , 7 , 8 , 9 , 10 , 40 . Excess of phosphides in Et2O – as well as excess of LiPH2 – favourably forms 10 . Li2PH (virtually free of Li3P and LiPH2) is obtained by reaction of LiPH2 · DME with LiBu; Li3P by reaction of PH3 with LiBu in toluene. Isomerization by Li/H migration determines the course of reaction of the PH-bearing compounds with Li-phosphides. With Me2SiCl2 Li3P mainly generates compound 10 . The reaction of the Li-phosphides with Et2SiCl2 mainly leads to (HP? SiEt2)3 18 and (HP? SiEt2)2 17 as well as to Et2Si(PH2)Cl 11 , Et2Si(PH2)2 12 , (ClEt2Si)2PH 13 , H2P? SiEt2? PH? SiEt2Cl 14 , (H2P? SiEt2)2PH 15 and 16 . In the reaction with LiPH2 · DME the same compounds are obtained and isomerization by Li/H migration (formation of PH3) already begins at ?70°C. In toluene ClEt2Si? P(SiEt2)2P? SiEt2Cl is additionally formed. Derivatives of 9, 10, 40 are not observed. The reaction of (t-Bu)2SiCl2 with LiPH2 leads to HP[Si(t-Bu)2]2PH 20 (yield 76%) and formation of PH3, the reaction with Li2PH to 20 (54%) besides HP[Si(t-Bu)2]2PLi 21 . 相似文献
Unprecedented silyl‐phosphino‐carbene complexes of uranium(IV) are presented, where before all covalent actinide–carbon double bonds were stabilised by phosphorus(V) substituents or restricted to matrix isolation experiments. Conversion of [U(BIPMTMS)(Cl)(μ‐Cl)2Li(THF)2] ( 1 , BIPMTMS=C(PPh2NSiMe3)2) into [U(BIPMTMS)(Cl){CH(Ph)(SiMe3)}] ( 2 ), and addition of [Li{CH(SiMe3)(PPh2)}(THF)]/Me2NCH2CH2NMe2 (TMEDA) gave [U{C(SiMe3)(PPh2)}(BIPMTMS)(μ‐Cl)Li(TMEDA)(μ‐TMEDA)0.5]2 ( 3 ) by α‐hydrogen abstraction. Addition of 2,2,2‐cryptand or two equivalents of 4‐N,N‐dimethylaminopyridine (DMAP) to 3 gave [U{C(SiMe3)(PPh2)}(BIPMTMS)(Cl)][Li(2,2,2‐cryptand)] ( 4 ) or [U{C(SiMe3)(PPh2)}(BIPMTMS)(DMAP)2] ( 5 ). The characterisation data for 3 – 5 suggest that whilst there is evidence for 3‐centre P?C?U π‐bonding character, the U=C double bond component is dominant in each case. These U=C bonds are the closest to a true uranium alkylidene yet outside of matrix isolation experiments. 相似文献
Reaction of [(Me3Si)2CH]2Al? CH2? Al [CH(SiMe3)2]2 with Neopentyllithium: Formation of {[(Me3Si)2CH]2Al? CH2? Al [CH(SiMe3)2]2CH2CMe3} ? [Li(TMEDA)2]⊕ The recently synthesized methylene bridged dialuminium compound [(Me3Si)2CH]2Al? CH2? Al [CH(SiMe3)2]2 reacts with neopentyl lithium in the presence of TMEDA to give the stable {[(Me3Si)2CH]2Al? CH2? Al [CH(SiMe3)2]2CH2 · CMe3}? [Li(TMEDA)2]⊕ decomposing at 115°C. The aluminium atoms therein are not additionally bridged, but the new substituent is occupying a terminal position as detected by crystal structure determination. A compound is formed containing a saturated, fourfold coordinated neighbouring a formally unsaturated, threefold coordinated aluminium atom. Due to high sterical restrictions the Al? C bonds are lengthened up to 209.0(3) pm at the alanate site and the Al? C? Al angle in the methylene bridge is extraordinarily enlarged to 144.4(2)°. 相似文献
