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1.
Formation of Organosilicon Compounds. LXII. Partial Brominated Carbosilanes The photobromination of 1 leads to compound 2 as well as to C-chlorinated derivatives if the time of reaction is prolonged. Compound 2 is also formed from (Br2Si–CH2)3; Gl. (1) see ?Inhaltsübersicht”?. In a corresponding reaction (Cl3Si–CH2)2SiCl2 gives successively Cl3Si–CHBr–SiCl2–CH2–SiCl3, Cl3Si–CBr2–SiCl2–CH2–SiCl3 and Cl3Si–CCl2–SiCl2–CH2–SiCl3. (Cl3Si)2CBr2 is accessible through the photobromination of (Cl3Si)2CH2. The reactivity of the CBr2-group is quite obvious in the reaction of Cl2Si–CBr2–SiCl2–CH2–SiCl3 with LiAlH4 yielding (H3Si–CH2)2SiCl2 as well as in the reaction of compound 2 with CH3MgCl yielding [(CH3)2Si–CH2]3. By treatment of the SiH groups with bromine the preparation of compounds with the general formulas CH3SiHnBr3?n; (H3?nSiBrn)2CH2; (H3?nSiBrn? CH2)2SiH2?nBrn; (H2?nBrnSi? CH2)3 and (H3?nSiBrn)2CCl2 is possible. Analysis of the nmr spectra shows that 1,3-Dibromo-1,3,5-trisilacyclohexane is formed to 67% in the trans and to 33% in the cis configuration; 1,3,5-Tribromo-1,3,5-trisilacyclohexane is formed to 80–90% in teh cis-trans configuration. The results of 1H and 29Si NMR investigations are reported.  相似文献   

2.
1. Photochlorination in CCl4 of the Si-chlorinated carbosilanes (Cl3Si? CH2)2SiCl2 and (Cl2Si? CH2)3 leads to totally chlorinated compounds, e. g. (Cl3Si? CCl2)2SiCl2. After chlorination has started at one CH2 group, formation of a CCl2 group is preferred before another CH2 group is involved into the reaction. Thus preparation of compounds a, b, c is possible. Cl3Si? CCl2? SiCl2? CH2? SiCl3 (a) for (b) and (c) (see “Inhaltsübersicht”). SO2Cl2 (benzoyl peroxide) as chlorinating agent reacts more slowly, and opens an access to carbosilanes containing CHCl groups such as (d), Cl3Si-CHCl? SiCl2? CH2? SiCl3 (e). Reactions of compounds (a) to (d) with LiAlH4 yields carbosilanes with SiH groups, and partially chlorinated C atoms. 2. By the high reactivity of Si? CCl2? Si groups an exchange of Cl atoms of CCl groups in perchlorinated carbosilanes is possible for H atoms of Si? H groups in perhydrogenated carbosilanes, thus allowing the preparation of compounds containing CHCl and SiHCl groups, e. g. according to Gl.(1) (Inhaltsübersicht). Further reactions, formulated as the last equations in Inhaltsübersicht, are reported as well as the rearrangement of H3Si? CHCl? SiH3.  相似文献   

3.
This paper contains:
  • 1 The synthesis of the 1.3-disilacyclopentenes (a)(b)(2) and of the 1.3-disilacyclo-butane (c); formulas see above.
  • 2 The synthesis of the 1.3-disilacyclopentane skeleton (d) and of the SiCl-functional derivatives (e) (f ) (g) (h) (i) as well as of SiH-containing derivatives, e.g. (j).
  • 3 The chlorination of (i) with SO2,Cl2, yielding (k) and (l), and the formation of (m) from (k) with K-methypyrrolidine.
  • 4 The synthesis of the spirane (n).
  • 5 The synthesis of the ten-membered ring(o) and of the unsaturated derivatives (p)and (q). Besides the synthetic routes, spectroscopic data (ir, pmr, and mass spectra) of the cyclic compounds as well as of the intermediate products are given.
  相似文献   

4.
Formation of Organosilicon Compounds. 90. Synthesis of C-linked Carbosilanes n-buLi metallates 1 to give 2 , which with phme2SiCl (ph = C6H5, me = CH3) forms 3 . This compound yields 4 with Br2. Lithiation of 3 yields 5 which for sterical reasons cannot be substituted with phme2SiCl. The spiro compounds 10 and 11 are available by treating 2 with (Brme2Si)2CH2 or (Brme2SiCH2)2-Sime2, resp. By means of n-buLi the CBr group in 4 can be metallated. On warming to 20°C the lithiated compound eliminates LiBr via an highly reactive intermediate to form 12 , 12 shows an extraordinary stability of the Si? C fourmembered ring against HBr or Br2  相似文献   

5.
Formation of Organosilicon Compounds. 109. Reactions of Perhydrogenated Carbosilanes with Alkyl-Lithium Compounds Si-hydrogenated linear carbosilanes react with MeLi or nBuLi to give the Si-alkylated derivatives. In contrast to the Si-methylated derivatives of (H3Si? CH2)2SiH2 1 and (H3Si)2CH2 2 and to (Me2Si? CH2)3 no lithiation of CH2 groups is observed. Such, 1 with nBuLi yields nBuH2Si? CH2? SiH2? CH2? SiH3 5 and (nBuH2Si? CH2)2SiH2 6 . 2 reacts with nBuLi to give nBuH2Si? CH2SiH3 7 and (nBuH2Si)2CH2 8 besides of 1, 5 und 6 . The latter results from a cleavage of a Si? C bond in 2 Producing nBuSiH3 and LiCH2? SiH3 which combines with 2 to 1 . Subsequently 1 forms 5 and 6 . No higher alkylated derivatives of 1 or 2 could be detected.  相似文献   

6.
By LiAlH4 (Cl3Si)2CH2, (Cl2Si? CH2)2SiCl2 are reduced to (H3Si)2CH2 (a), (H3Si? CH2)2SiH2 (b) and (H2Si? CH2)3(c). However with the compounds (Cl3Si)2CCl2, (Cl3Si? CCl202SiCl2 and (Cl2Si? CCl2)3 cleavages of the Si? C-bond and reduction of the CCl-groups occur apart from the normal reduction of the Si-Cl-groups to (H3Si)2CCl2 (d), (H3SiCCl2)2SiH2 (e) and (H2Si? CCl2)3. Excess LiAlH4 favours this cleavage, the exact amount of a quarter of a mole LiAlH4 per SiCl-group allows the formation of (d), (e), (f). The cleavage of (e) is in accordance with: (1), (2),(3). Therefore SiH34 and (H3Si)2CCl2 are the main-reaction-products and CH3SiH3 is formed acc. to equ. (3). Because of the cleavage of (H2Si? CCl2)3 with LiAlH4 H3Si? CCl2? SiH2? CH3and H3Si? CH2? SiH2? CH2? SiH2? CH3 are preferentially formed after the hydrolysis. The CH2-containing compounds (a), (b), (c) cannot be cleaved in an analogous reaction.  相似文献   

7.
8.
Formation of Organosilicon Compounds. 67. Studies of Metallorganic Synthesis of Si-methylated and C-chlorinated Carbosilanes Using Chlorocarbenoids Synthesis and reactions of C6H5me2Si? CCl2H (A), (H5C6me2Si)2CCl2 (B), and me2Si(CCl2H)2 (C) were investigated in order to find conditions for the synthesis of C-functional carbosilanes via chlorocarbenoids. (A) and (B) react with n-butyl-Li(buLi) (?100°C/THF/ether/pentane) yielding H5C6me2Si? CCl2Li and (H5C6me2Si)CClLi, respectively. These lithium reagents form (B) and(H5C6me2Si)3CCl with H5C6me2SiCl. In the reaction of (H5C6me2Si)3CCl with lithium (H5C6me2Si)3CLi (D) is obtained. (D) forms with H2O/HCl the compound (H5C6me2Si)3CH which is cleaved by HBr yielding (Brme2Si)3CH. (C) gives LiCCl2? Sime2(CCl2H) with buLi (molar ratio 1:1) in a low temperature reaction. Clme2Si? CCl2? Sime2(CCl2H) is formed in the reaction of LiCCl2? Sime2? CCl2H with Sime2CCl2 (yield >90%). Reacting (C) and buLi (1:3) and treating this solution with Sime2CI2 gives (ClSime2)2C?CH Sime2Cl (>85%) via a monosilacyclopropane intermediate. In the inverse reaction, if (C) is added to buLi, (HCCl2)me2SiC?Sime2(CCl2H) is one of the isolated reaction products. If buLi is added to (C) (2:l) and this solution is treated with Sime3Cl, compounds me3Si? CCL2? Sime2? CCL2H, me3Si? CClH? Sime2(CCl2H), (me3Si? CC12)2Sime2, me3Si? CHCI? Sime2? CC12? Sime3 are isolated. The same products were obtained in the reaction of me3Si? CCl2? Sime2? CCl2H with buLi and me3SiCl.  相似文献   

9.
Formation of Organosilicon Compounds. 93. Investigations of the Mechanism of the AlBr3 Initiated Formation of Cyclic Carbosilanes. The mechanism of the formation of ringsystems in carbosilanes with AlBr3 is investigated using the deuterium compounds 1a and 3a . The number of deuterium atoms in the methyl groups of the reaction products shows at which points of the molecules the regrouping occurs under formation of the ringsystem. In the first initially the reaction of 1a yields D3C? Si(CH3)3 and 2a under separation of a CD3 group. The rearrangement forming 2a occurs at the marked Si? C-bonds (formula 1a ). No Al-organic intermediate compound is observed under cleavage of Si? C bond. Therefore the formation of ring-systems is based on the polarisation by the Lewis-acid AlBr3. Compound 3a reacts in an analogous way, what is shown by the isolation of Sime4 and 4a . The cleavage of the bonds is marked in formula 3a . The reaction of 8 forming 9 and (Sime3)2CH2 follows the same mechanism; it is investigated by 1H and 27Al-NMR spectroscopy.  相似文献   

10.
Formation of Organosilicon Compounds. 77. Formation of Carbosilanes from Methylsilanes The products formed by pyrolysis of me3SiH, me2SiH2, and meSiH3 are reported. Sime4 and the mentioned methylsilanes were reacted in a plasma, and the products are compared to those of the pyrolysis. The pyrolysis of me3SiH and me2SiH2 essentially yields the same groups of carbosilanes which are accessible by thermal decomposition of Sime4, if the range is restricted to compounds with 4 Si atoms at most. Cylic carbosilanes are the main products of the pyrolysis of me3SiH, and amoung these, 1,3,5-trisilacyclohexanes and 1,3,5,7-tetrasilaadamantanes are preferrently formed. From me2SiH2 above all linear compounds as 1,3-disilapropanes are obtained. This is attributed to the chosen experimental procedure in which they not subject to further reaction. In the pyrolysis of meSiH3 a yellow solid is formed besides little amounts of meH2Si? SiH2me. Compared to the compounds formed by pyrolysis of Sime4, the carbosilasen obtained from me3SiH and me2SiH2 possess more SiH substituents. Also the decomposition of Sime4 in a plasma preferrently yields carbosilanes, mainly linear compounds with 2 or 3 Si atoms.  相似文献   

11.
Formation of Organosilicon Compounds. 102. Reaction of Chlormethanes with Elemental Silicon. (Formation and Investigation of Linear Carbosilanes) Reactions of CH2Cl2, HCCl3 and CCl4 with silicon (Cu catalyst) in a fluid bed at about 320°C were carried out to investigate especially the Si-rich compounds. In the reactions of CH2Cl2 and CHCl3, but not of CCl4, in addition to already published compounds Si-rich viscous products are formed. The SiCl-containing mixtures were reacted with LiAlH4, and the SiH-containing derivatives were separated by means of HPLC. CH2Cl2/Si forms unbranched chains of carbosilanes as SinCn–1H4n (n = 4—12,2 terminal SiH3 groups) and SinCnH4n+2 (n = 4—9, 1 terminal SiH3 and 1 CH3 group) as well as 1,3,5-trisilacyclohexanes with carbosilane chains of various length attached either to a Si atom or to a C atom. CHCl3/Si yields in addition to unbranched chains with terminal silyl group chains with one or two C-branches and 1,3,5-trisilacyclohexanes with 1, 2, or 3 silyl substituents attached to C atoms. The structure of the isolated compounds was investigated by nmr and mass spectrometry.  相似文献   

12.
Formation of Organosilicon Compounds. 89. Selective Photobromination of Si-methylated Carbosilanes A selective photobromination of the C atoms in the skeleton of Si-methylated carbosilanes is reported. (me3Si? CH2)2Sime2 reacts to me3Si? CBr2? Sime2? CH2? Sime3 in good yields (me = CH3); the second CH2 group is considerably slower brominated. Photobromination of (me2Si? CH2)3 consecutively yields a and b . Also from (me2Si? CH2)4 the derivative with one CBr2 group is accessible. Bromination of tertiary CH groups is highly preferred; this is shown by the selective formation of c . The C-bromination of SiBr-substituted carbosilanes is significantly more difficult; nevertheless (Brme2Si)2CH2 selectively forms (Brme2Si)2CBr2. Brme2Si? CH2? Sime2? CH2? Sime3 forms Brme2Si? CH2? Sime2? CBr2? Sime3, i. e., only the CH2 group non-adjacent to SiBr is attacked. The formation of CHBr groups could not be detected. Higher temperatures and longer reaction times increase the formation of polymers.  相似文献   

13.
Formation of Organosilicon Compounds. 87. 2,8,9-Trioxa-1,3,5,7-Tetrasilaadamantane Hydrolysis of cis-cis-1,3,5-tribromo-1,3,5-tri-t-butyl-1,3,5-trisilacyclohexane yields the trisilanole 2 (mp. 205°C) which forms the tetrasilaadamantane 3 with SiCl4/et2NH. Hydrolysis of 3 yields 4 (Formulae see “Inhaltsübersicht”).  相似文献   

14.
Formation of Organosilicon Compounds. 92. Formation and Structure of Octamethylhexasila-hexascaphane By rearrangement and abstraction of CH4 at the presence of AlBr3 2 forms 3 , and 6 forms 7 , which is also obtained reacting 8 and 9 under the same condition. Lithination of 1, 1, 3, 5, 5, 7, 7, 9, 9-Nonamethyl-1, 3, 5, 7, 9-pentasiladecaline yields 12 , which is trapped with me3SiCl to form 6 . Convertation of 13 to 14 leads to 8 by reaction with ClSi(CH2—Sime3)3. Compound 7 is characterized by NMR and mass spectroscopy as well as X-ray structural analysis. 1, 3, 5, 7, 9, 9, 11, 11-Octamethyl-1, 3, 5, 7, 9, 11-hexasila-hexascaphane 7 crystallizes in the monoclinic space group P21/n (No. 14) with a = 3296.7 pm, b = 1536.2 pm, c = 891.9 pm, β 91.71° and Z = 8 formular units. Both crystallographic independent molecules have approximately the symmetry C2. The differences of corresponding bond lengths, bond angles and torsion angles are unimportant. But there is a distinct dependence of the Si? C bond length relative to the function of the bond in the molecule (Averages: Si? C) (endo) = 188.4 pm, Si? C (exo) = 187.6 (pm).  相似文献   

15.
Formation of Organosilicon Compounds. 100. Isolation of Higher Molecular Carbosilanes from the Pyrolysis Products of Tetramethylsilane A systematic investigation of the carbosilanes containing 6 to 9 Si atoms per molecule formed by pyrolysis of SiMe4 was achieved by means of column chromatographic separations combined with HPLC. 11 pure compounds and mixtures of the isomers of 7a and 7b as well as of 11 and 15 were isolated. The predominant structure is that of the carborundanes using only Me and H as Si substituents. Only in compounds 8 and 13 some of the Si? C sixmembered rings are in the chair form. In compounds 17 and 18 another possibility of connecting 1,3,5,7-tetrasilaadamantane frameworks to higher molecular carbosilanes is realized.  相似文献   

16.
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   

17.
Formation of Organosilicon Compounds. 86. Si-phenyl and Si-butyl Substituted 1,3,5-Trisilacyclohexanes By treating (BrHSi? CH2)3 with phMgBr or t-buLi, resp., and subsequent separation of the isomers, the pure cis-cis substituted 1,3,5-trisilacyclohexanes I are accessible which yield II (Formula see Inhaltsübersicht) by reaction with Br2. (F2Si? CH2)3 8 can be transferred into (ph2Si? CH2)3 7 with phLi. With HCl/AlCl3 7 forms (Cl2Si? CH2)3, whereas even with an excess of Br2 it only yields (phBrSi? CH2)3. Cleavage of 7 with one equivalent of Br2 yields (H2C? Si)3ph5Br 14, which with LiAlH4 forms (H2C? Si)3ph5H 10. 10 is not so easy to obtain via (H2C? Si)3ph5F 9 from the reaction of 8 with 5 equivalents of phLi. All of the SiH and SiBr groups in I and II, resp., occupy axial positions as well as the Br atom in 14 the H atom at Si in 10 and the F atom in 9.  相似文献   

18.
Formation of Organosilicon Compounds. 98. Reaction of Silylated Phosphorus Ylides with PCl3 The reaction of Si-substituted phosphorus ylides as Me2Si(CH2? SiMe2)2C?PMe3Br 1 , Cl2Si(CH2? SiCl2)2C?PMe2Cl 2 , and (Cl3Si)2C?PMe2Cl 3 with PCl3 yields (Cl2P)2C?PMe2Cl 5 by chlorinating cleavage of the Si-ylid-C bond. Besides 5 also (ClMe2SiCH2)2SiMe2, (Cl3SiCH2)2SiCl2, resp. SiCl4 result from the reaction of 1, 2 and 3 with PCl3. (Cl2P)2C?PMe2Cl forms colourless crystals, mp. 84°C.  相似文献   

19.
Formation of Organosilicon Compounds. LVIII. Synthesis of a Carbosilane with Propellane Structure 1 (· ? C resp. CH2; x ? Si(CH3)2 resp. Si) is formed by a coupling reaction of BrSi(CH2? Sime2? CH2? Sime2Br)3 2 with CCl4 and Li. The reaction of C6H5me2Si? CH2Li with Clme2Si? CH2Br leads to C6H5me2Si? CH2? Sime2? CH2Br. Metallation with lithium and succeeding reaction with Cl3SiC6H5 produces compound C6H5Si(CH2? Sime2? CH2? Sime2C6H5)3, which than forms 2 by cleavage with bromine.  相似文献   

20.
Formation of Organosilicon Compounds. 83. Formation, Reactions, and Structure of Ylides Generated from Perchlorinated Carbosilanes The CCl-moiety in perchlorinated carbosilanes as (Cl3Si)2 a, Cl3Si? CH2? SiCl2? CCl2? SiCl3 b, (Cl3Si? CCl2)2SiCl2 c or (Cl2Si? CCl2)3 d, e.g., cleaves the Si? P bond of me3Si? Pme2 e (me = CH3); and by subsequent rearrangement ylides are formed. Such, treating e with a yields (Cl3Si)2CPme2Cl 1, which also results from the reaction of me2P? Pme2 with a. The ylides also can be obtained by means of treating the carbosilanes a, b, c or d with LiPme2. Thus, c with one mole of LiPme2 yields Cl3Si? CCl2? SiCl2? C(Pme2Cl)? SiCl3 or Cl3Si? C(Pme2Cl)? SiCl2? C(Pme2Cl)? SiCl3, resp., with two moles of LiPme2. The corresponding Si-methylated derivates do not form ylides; (me3Si)2CCl2, e.g., with e in benzene yields me3Si? CH(Pme2)? Sime3. One mole of Lime methylates 1 to yield (Cl3Si)2CPme3 11. With either LiPme2, me3Si? Pme2 or Me2P? Pme2 1 forms (Cl3Si)2CPme2-Pme2. Reacting 1 with CH3OH/(C2H5)2NH, (Cl3Si)[SiCl2(OCH3)]CPme2(OCH3) is formed. Ylides also result from the reactions of partially C-chlorinated 1,1,3,3,5,5-hexachloro-1,3,5-trisilacyclohexanes with me3Si? Pme2, (Cl2Si? CCl2)3 with three moles of me3Si? Pme2 or LiPme2, resp., yields (Cl2Si? CPme2Cl)3 16, the 1,1,3,3,5,5-Hexachlor-2,4,6-tris(chlordimethylphosphoranyliden)-1,3,5-trisilacyclohexan, which crystallizes with one mole of monoglyme. X-ray structure determinations revealed that 1, 11 and 16 are planar. As well the (P? C) as the (Si? C) bond lengths are remarkably shortened; in 1 (P? C) to 173.3 pm, (Si? C) to 173.3 pm, (Si? C) to 179.5 pm, in 16 (P? C) to 168.7 pm, (Si? C) to 180 pm. The (Si? C) and (P? C) bond orders amount to about 1.33, and are relatively equally distributed. Therefore, the charge of the formal carbanion is equally distributed, which shall be expressed by means of the following kind of writing for 1 and 16 see “Inhaltsübersicht”.  相似文献   

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