- SOME PRACTICAL USES OF THE DISILANE RESIDUE FROM THE DIRECT SYNTHESIS OF METHYLCHLOROSILANES
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Some practical uses for the disilane residue from the direct synthesis of methylchlorosilanes have been proposed.This residue can be converted into organochloro-(Me2SiCl2, MeSiCl3, Me3SiCl) or organohydrochloro-monosilanes (HMeSiCl2, HMe2SiCl).These disilanes can also be used for the synthesis of alkyl (haloalkyl, alkenyl, aryl, etc.) methyldichlorosilanes or alkyl (haloalkyl, alkenyl, aryl, etc.) trichlorosilanes.The reductive properties of the Si-Si bond of these species have been utilized (e.g. in the reduction of phosphine oxides into the corresponding phosphines).Polysilanes resulting from the disproportionation of this residue are precursors of polycarbosilanes.
- Calas, Raymond,Dunogues, Jacques,Deleris, Gerard,Duffaut, Norbert
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- METHOD FOR THE DEHYDROGENATION OF DICHLOROSILANE
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Dichlorosilane and trichlorosilane are dehydrogenated at elevated temperature in the presence of an ammonium or phosphonium salt as a catalyst, and a halogenated hydrocarbon or hydrogen halide. The method may be used to synthesize organochlorosilane.
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Paragraph 0095
(2021/06/22)
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- PRODUCTION METHOD FOR LINEAR AND CYCLIC TRISILAALKANE
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The present invention relates to a preparation method for a linear or cyclic trisilaalkane which is a substance useful in the preparation of polycarbosilane and silicon carbide precursors. Linear or cyclic trisilaalkane and organic trichlorosilane derivatives can be synthesized simultaneously and in high yield by reacting bis(chlorosily)methane having a Si—H bond, either alone or together with an organic chloride, using a quaternary organic phosphonium salt compound as a catalyst. Further, since the catalyst can be recovered after use, the present invention is very economical and is thus effective for mass-producing precursors for organic/inorganic hybrid substances.
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Page/Page column 6
(2011/04/19)
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- METHOD OF PREPARING ALLYLCHLOROSILANE DERIVATIVE
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Provided is a method of preparing allylchlorosilane, and more particularly, a method of preparing allylchlorosilane with high yield by Si—C coupling reaction of an allyl chloride derivativce with a hydrosilane derivative under specific reaction conditions without using a catalyst.
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Page/Page column 3
(2011/06/23)
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- Controlled introduction of allylic group to chlorosilanes
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Allylation of chlorosilanes has been achieved with allylsamarium bromide, especially in a controlled manner. Thus allylation of trisubstituted chlorosilanes (R3SiCl) afforded a variety of aryl, aralkyl, and alkenyl substituted allylsilanes. Dichlorosilanes (R2SiCl2) can either afford monoallylated silanes or diallylated silanes depending on the amount of allylsamarium bromide used. Similarly, trichlorosilanes (RSiCl3) can selectively afford mono-, di-, and tri-allylation products. Finally, perchlorosilane (SiCl4) was allylated stepwise and the corresponding silanes containing one, two, three or four allylic groups, respectively, were obtained in satisfactory yields.
- Li, Zhifang,Cao, Xiaojun,Lai, Guoqiao,Liu, Jinhua,Ni, Yong,Wu, Jirong,Qiu, Huayu
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p. 4740 - 4746
(2007/10/03)
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- Processes for manufacturing organochlorosilanes and dipodal silanes and silanes made thereby
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Processes are provided for producing organchlorosilanes and dipodal silanes in which an organic halide or alkene or chloralkene is reacted with a hydridochlorosilane in the presence of a quarternary phosphonium salt catalyst by providing sufficient heat to effect a dehydrohalogenative coupling reaction and/or a hydrosilylation reaction and venting the reaction to control reaction pressure and to remove gaseous byproducts from the reaction. The processes are preferably continuous using a catalyst in fluid form at reaction pressures not exceeding about 600 psi. The reactions may be carried out substantially isothermally and/or isobarically, for example in a plug flow reactor or continuous stirred tank reactor. The processes may produce novel silylated compounds including 1,2-bis(trichlorosilyl)decane or 1,2-bis(trimethoxysilyl)decane.
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Page/Page column 3; 6
(2010/02/10)
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- PROCESS FOR PREPARING ORGANOCHLOROSILANES BY DEHYDROHALOGENATIVE COUPLING REACTION OF ALKYL HALIDES WITH CHLOROSILANES
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The present invention relates to a process for preparing organochlorosilanes and more particularly, to the process for preparing organochlorosilanes of formula I by a dehydrohalogenative coupling of hydrochlorosilanes of formula II with organic halides of formula III in the presence of quaternary phosphonium salt as a catalyst to provide better economical matter and yield compared with conventional methods, because only catalytic amount of phosphonium chloride is required and the catalyst can be separated from the reaction mixture and recycled easily, wherein R1 represents hydrogen, chloro, or methyl; X represents chloro or bromo; R2 is selected from the group consisting of C1-17 alkyl, C1-10 fluorinated alkyl with partial or full fluorination, C2-5 alkenyl, silyl containing alkyl group represented by (CH2)nSiMe3-mClm wherein n is an integer of 0 to 2 and m is an integer of 0 to 3, aromatic group represented by Ar(R′)q wherein Ar is C6-14 aromatic hydrocarbon, R′ is C1-4 alkyl, halogen, alkoxy, or vinyl, and q is an integer of 0 to 5, haloalkyl group represented by (CH2)pX wherein p is an integer of 1 to 9 and X is chloro or bromo, and aromatic hydrocarbon represented by ArCH2X wherein Ar is C6-14 aromatic hydrocarbons and X is a chloro or bromo; R3 is hydrogen, C1-6 alkyl, aromatic group represented by Ar(R′)q wherein Ar is C6-14 aromatic hydrocarbon, R′ is C1-4 alkyl, halogen, alkoxy, or vinyl, and q is an integer of 0 to 5; and R4 in formula I is the same as R2 in formula III and further, R4 can also be (CH2)pSiR1Cl2 or ArCH2SiR1Cl2, when R2 in formula III is (CH2)pX or ArCH2X, which is formed from the coupling reaction of X—(CH2)p+1—X or XCH2ArCH2X with the compounds of formula II; or when R2 and R3 are covalently bonded to each other to form a cyclic compounds of cyclopentyl or cyclohexyl group, R3 and R4 are also covalently bonded to each other in the same fashion.
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- Process for preparing organochlorosilanes by dehydrohalogenative coupling reaction of alkyl halides with chlorosilanes
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The present invention relates to a process for preparing organochlorosilanes and more particularly, to the process for preparing organochlorosilanes of R4R3CHSiR1Cl2(I) by a dehydrohalogenative coupling of hydrochlorosilanes of HSiR1Cl2(II) with organic halides of R2R3CHX (III) in the presence of quaternary phosphonium salt as a catalyst to provide better economical matter and yield compared with conventional methods, because only a catalytic amount of phosphonium chloride is required and the catalyst can be separated from the reaction mixture and recycled easily.
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- Dehydrohalogenative coupling reaction of organic halides with silanes
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The present invention relates to methods for making the compounds of formula I which is a dehydrohalogenative coupling of hydrochlorosilanes of formula II with organic halides of formula III in the presence of a Lewis base catalyst. R3CH2SiR1Cl2??(I) HSiR1Cl2??(II) R2CH2X??(III) In formulas I and II, R1represents a hydrogen, chloro, or methyl; in formula III, X represents a chloro or bromo; in formula III, R2can be selected from the group consisting of a C1-17alkyl, a C1-10fluorinated alkyl with partial or full fluorination, a C1-5alkenyl groups, a silyl group containing alkyls, (CH2)nSiMe3-mClmwherein n is 0 to 2 and m is 0 to 3, aromatic groups, Ar(R′)1wherein Ar is C6-14aromatic hydrocarbon, R′ is a C1-4alkyl, halogen, alkoxy, or vinyl, and q is 0 to 5, a haloalkyl group, (CH2)pX wherein p is 1 to 9 and X is a chloro or bromo; or an aromatic hydrocarbon, Ar CH2X wherein Ar is C6-14aromatic hydrocarbon and X is a chloro or bromo. in formula I, R3is the same as R2in formula III and further, R3can also be (CH2)pSiR1Cl2or ArCH2SiR1Cl2when R2in formula III is (CH2)pX or ArCH2X, because of the coupling reaction of X with the compound of formula II.
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- One-pot enantioselective synthesis of optically active homoallylic alcohols from allyl halides
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A one-pot, convenient method for the preparation of optically active homoallylic alcohols from allyl halides was developed. Allyltrichlorosilanes were generated in situ from allyl halides and trichlorosilane in the presence of cuprous chloride and tertiary amine. Without isolation of the allyltrichlorosilanes, benzaldehyde and chiral biquinoline N,N'-dioxide were introduced into the same flask, producing the corresponding homoallylic alcohols with good to high enantioselectivities.
- Nakajima, Makoto,Saito, Makoto,Hashimoto, Shunichi
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p. 306 - 307
(2007/10/03)
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- Reactions of Tetrachlorogermane with Allyl Chloride and Methallyl Chloride in the Presence of Hexachlorodisilane as an Initiator
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Allyl chloride and methallyl chloride react with tetrachlorogermane in the presence of hexachlorodisilane to give as major products allyltrichlorogermane and allyltrichlorosilane in the former case and (2-methyl-2-propenyl)trichlorogermane and (2-methyl-2-propenyl)trichlorosilane in the latter case. The reaction schemes are proposed and discussed.
- Chernyshev,Komalenkova,Yakovleva,Bykovchenko,Khromykh,Bochkarev
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p. 894 - 897
(2007/10/03)
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- Reaction of Hexachlorodisilane with Trichloroethynylsilane and 2-Propynyl Chloride in the Gas Phase
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Reaction of acetylenic compounds (trichloroethynylsilane and 2-propynyl chloride) with hexachlorodisilane in the gas phase at 450-520°C was studied. Main products of the reaction were identified, and a mechanism of their formation was proposed. It was shown that of the two reaction centers of 2-propynyl chloride (C=≡C and C-Cl) only the C-Cl bond is involved in reaction with dichlorosilylenes generated from hexachlorodisilane.
- Chernyshev,Komalenkova,Kapitova,Bykovchenko,Khromykh,Bochkarev
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p. 1043 - 1046
(2007/10/03)
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- Gas-Phase Reactions of Hexachlorodisilane with Vinyl Chloride and Allyl Chloride
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Gas-phase reactions of hexachlorodisilane with vinyl chloride and allyl chloride is studied. Dichlorosilylene generated from Si2Cl6 reacts with the above chloroalkenes mainly at the C-Cl bond to form alkenyltrichlorosilanes. The yields of vinyltrichlorosilane and allyltrichlorosilane are 45-63 and 49-81%, respectively. A mechanism of the reactions of Si2Cl6 with vinyl chloride and allyl chloride is proposed.
- Chernyshev,Komalenkova,Kapitova,Bykovchenko,Khromykh,Bochkarev
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p. 1447 - 1450
(2007/10/03)
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- Proton Addition to Silylstyrenes: Overcoming the Predilection for Protiodesilylation
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Normally, organosilyl nucleophiles such as vinylsilanes and allylsilanes undergo protiodesilylation reactions with protons.To favour addition reactions under these conditions, the ligands on silicon have been modified such that the leaving group ability and, simultaneously, the β-effect of the silyl group is reduced.In the case of allylsilanes, the use of dichlorosilyl groups does not significantly favour addition over substitution processes at the olefin.However, with vinylsilanes bearing a second ?-nucleophile, a dichlorosilyl group can be used to regioselectively direct the formation of two bonds (C-H and C-C) sequentially in a process in which the silicon is not lost from the molecule, but may ultimately be cleaved leading to the formation of diols.Thus, benzyldichlorostyrylsilane 7, after cyclization to 9 in the presence of triflic acid, is converted into diol 12.The synthetic utility of this process is restricted by the relatively low reactivity of the styryl ?-system and the necessarily reactive electrophiles needed to initiate the process.The effect of changing from electron-donating groups to electronegative groups on silicon on reaction mechanism is discussed.
- Henry, Courtney,Brook, Michael A.
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p. 11379 - 11390
(2007/10/02)
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- Facile and Highly Stereoselective Synthesis of Homoallylic Alcohols Using Organosilicon Intermediates
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Allyltrichlorosilanes regioselectively reacted with aldehydes in N,N-dimethylformamide (DMF) without a catalyst to afford the corresponding homoallylic alcohols in high yields.The reactions proceeded under neutral conditions, and syn- and anti-homoallylic alcohols were stereoselectively obtained from (Z)- and (E)-allyltrichlorosilanes, respectively.In these reactions, DMF coordinated to the silicon atom of the allyltrichlorosilanes to form hypervalent silicates, which in turn reacted with aldehydes smoothly.Solvent effects in these reactions were also examined.The reactions were applied to the one-pot synthesis of homoallylic alcohols from allylic chlorides via organosilicon intermediates.While syn-homoallylic alcohols were prepared from (Z)-allyl chlorides, anti-homoallylic alcohols were obtained from (E)-allyl chlorides.Unique regioselectivities in the reactions of 1-chloro-2,4-pentadiene were also found.Finally, the one-pot synthesis of homoallylic alcohols from 1,3-dienes is reported.
- Kobayashi, Shu,Nishio, Koichi
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p. 6620 - 6628
(2007/10/02)
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- Facile Synthesis of Both syn and anti Homoallylic Alcohols from Allyl Chlorides via Organosilicon Intermediates
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Highly regio- and diastereoselective synthesis of homoallylic alcohols from allyl chlorides via organosilicon intermediates are attained.While syn homoallylic alcohols were prepared from (Z)-allyl chlorides, anti homoallylic alcohols were obtained from (E)-allyl chlorides. 1-Chloro-2,4-pentadiene reacted at the γ position of the diene system regioselectively.
- Kobayashi, Shu,Nishio, Koichi
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p. 1773 - 1776
(2007/10/02)
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- Spectra and structure of small ring compounds - LXI. IR and Raman spectra, vibrational assignment, conformational stability and ab initio calculations of cyclopropylmethylsilane
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The IR (3500-50 cm-1) and Raman (3500-20 cm-1) spectra of gaseous and solid cyclopropylmethylsilane, c-C3H5-CH2SiH3, have been recorded.Additionally, we have obtained the Raman spectrum of the liquid and the IR spectrum of the sample trapped in an argon matrix.From these data a complete assignment of the normal vibrational modes is provided.The spectra of the gaseous and liquid phases have been interpreted on the basis of the predominance of a conformation having a gauche structure and this form exists exclusively in the solid.Ab initio Hartree-Fock structural optimizations with the 3-21G* and 6-31G* basis sets are consistent with the gauche rotamer lying ca. 800 cm-1 lower in energy than the cis conformation which has the SiH3 group cis to the cyclopropyl ring.The force fields obtained with the 3-21G* basis set have been used to perform a normal coordinate analysis.The cyclopropyl torsion has been observed as an IR band of hybrid contour centered at 80 cm-1 in the far-IR spectrum of the gas.Combination band spectra in the 2300-2000 cm-1 region of the mid-IR spectrum of the gas can be attributed to sum and difference bands of the SiH3 and cyclopropyl torsional modes with an SiH3 stretching mode.Analysis of these data leads to a barrier governing internal rotation of the silyl group of 687 +/- 50 cm-1.These results are compared with corresponding quantities in some similar molecules.
- Little, T. S.,Zhu, Xiang,Wang, Aiying,Durig, J. R.,Dakkouri, M.,et al.
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p. 1913 - 1934
(2007/10/02)
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- Kinetics of the reactions of allylsilanes, allylgermanes, and allylstannanes with carbenium ions
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Second-order rate constants for the reactions of para-substituted diarylcarbenium ions (ArAr'CH+ = 1) with allylsilanes 2, allylgermanes 3, and allylstannanes 4 have been determined in CH2Cl2 solution at -70 to -30°C. Generally, the attack of ArAr'CH+ at the CC double bond of the allylelement compounds 2-4 is rate-determining and leads to the formation of the β-element-stabilized carbenium ions 5, which subsequently react with the negative counterions to give the substitution products 6 or the addition products 7. For compounds H2C = CHCH2MPh3, the relative reactivities are 1 (M = Si), 5,6 (M = Ge), and 1600 (M = Sn). From the relative reactivities of compounds H2C=CHCH2X (X = H, SiBu3, SnBu3), the activating effect of an allylic trialkylsilyl (5 × 105) and trialkylstannyl group (3 × 109) is derived. This effect is strongly reduced, when the alkyl groups at Si or Sn are replaced by inductively withdrawing substituents, and an allylic SiCl3 group deactivates by a factor of 300 (comparison isobutene/2k). A close analogy between the reactions of alkenes and allylelement compounds with carbenium ions is manifested, and the different reaction series are connected by well-behaved linear free energy relationships. The relative reactivities of terminal alkenes and allylelement compounds are almost independent of the electrophilicities of the reference carbenium ions (constant selectivity relationship), thus allowing the construction of a general nucleophilicity scale for these compounds.
- Hagen, Gisela,Mayr, Herbert
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p. 4954 - 4961
(2007/10/02)
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- ONE-STEP REGIOSPECIFIC SYNTHESIS OF ALLYLIC SILANES - EXTENSION TO BENZYLSILANES
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Allyltrichlorosilanes are prepared according to a one-step regiospecific process based on the reaction of allyl chlorides with SiCl4 and NiCp2/HMPA (catalyst), in the presence of industrial methylchlorodisilane fraction.Benzyltrihalosilanes are similarly obtained.
- Lefort, Marcel,Simmonet, Christian,Birot, Marc,Deleris, Gerard,Dunogues, Jacques,Calas, Raymond
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p. 1857 - 1860
(2007/10/02)
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