Dehalosilylation

Dehalosilylation reaction. The dehalosilylation reaction was introduced by Wells et al. in 1986, who obtained arsinogallanes by reaction of R2AsTms with chlorogallanes under elimination of TmsCl [68] (Scheme 7). 

Scheme 7. First synthesis of Ga—As compounds by dehalosilylation reaction...

Dehydrosilylation reaction. While the dehalosilylation reaction is very powerful for the synthesis of Ga—Sb and In—Sb heterocycles, this reaction type completely failed for the synthesis of the corresponding stibinoalanes. Only the reaction of Me2AlCl with Sb(Tms)3, leading to the formation of [Me(Gl)AlSb(Tms)2]3 38, yielded an Al—Sb heterocycle [36a]. However, 38 obviously was not formed by dehalosilylation but by tetramethylsilane elimination reaction (Scheme 9). 

Other synthetic pathways for the preparation of group-13-element antimony compounds include dehydro- and dehalosilylation reactions of R2SbSiMe3 or Sb(SiMe3)3 with R MX or MX3 (R = SiMe3, t-Bu R = Me, Et, i-Bu M = Ga, In X = H, Cl).53 A review of the chemistry of these potential precursors for 13-15 semiconductors was recently published.55... 

Wells et al. introduced the dehalosilylation reaction for the synthesis of group 13/15 compounds in 1986. Reactions between silylarsines of the type R/AsSiMe3 with chlorogallanes occurred with elimination of Me3SiCl, leading to the formation of arsinogallanes of the types [Cl2GaAsR2]x79 (Scheme 6). 

Scheme 6. Wells initial studies on the synthesis of arsinogallanes by dehalosilylation reaction.

Scheme 7. Synthesis of heterocyclic stibinogallanes and -indanes by dehalosilylation reaction.

Dative bonding, 229 Decamethylmetallocenes, 1-2, 6, 8-9, 20 of silicon see Decamethylsilicocene Decamethylsilicocene, 1-34 chemistry of, 9-31 structure, 4-7 synthesis, 3 1 Decomposition betaines, 37-38, 78-87 thiobetaines, 57-63, 65 for film deposition, 304-306 Dehalosilylation reaction, 260-262 Dehydrosilylation reaction, 262-264 Density functional theory (DFT), 177 Deposition, film, 257-258, 265, 301-303 DFT (density functional theory), 177 Diazasilole derivatives, decamethylsilicocene gives, 24-25... 

In the last decade, this so-called dehalosilylation reaction was shown to be generally applicable for the synthesis of four- and six-membered Ga - Sb and In - Sb heterocycles as summarized in Table 3 [19,24]. 

Tables Heterocyclic stibinogallanes and -indanes of the type [R2MSb(SiMe3)2]x (M = Ga, In) synthesized by dehalosilylation reaction...

The most striking feature of this reaction type is the simple formation of completely alkyl-substituted M - Sb heterocycles, which are hardly accessible by dehalosilylation and dehydrosilylation reactions due to the tendency of silylsubstituted dialkylstibines R2SbSiMe3 to undergo ligand exchange reactions at elevated temperatures, leading to the synthesis of partially silylsubstituted hetero cycles [28]. 

Tris(trimethylsilyl)arsine and lithium bis(trimethylsilyl)arsenide are valuable reagents for dehalosilylation and salt elimination reactions, respectively. Each compound reacts with a wide variety of metal halides to form metal-arsenic bonds.1, 2 The syntheses reported herein are a modification of the published procedures of Becker et al.,3 designed to minimize the use of Schlenk techniques and to allow researchers to prepare two very useful compounds with a minimum of danger. However, since these compounds do... 

Amidocarbonylation aldehydes, 11, 512 enamides, 11, 514 overview, 11, 511-555 Amido complexes with bis-Cp titanium, 4, 579 Group 4, surface chemistry on oxides, 12, 515 Group 5, surface chemistry on oxides, 12, 524 with molybdenum mono-Cp, 5, 556 with mono-Cp titanium(IV) alkane elimination, 4, 446 amine elimination, 4, 442 characteristics, 4, 413 via dehalosilylation reactions, 4, 448 HCL elimination, 4, 446 metathesis reactions, 4, 438 miscellaneous reactions, 4, 448 properties, 4, 437... 

Cyclopentadienones, in molybdenum carbonyls, 5, 451 Cyclopentadienyl alkenes, with niobium, 5, 76 Cyclopentadienyl-alkoxo complexes, with Ti(IV), 4, 495 Cyclopentadienyl alkyl complexes, with niobium, 5, 66 Cyclopentadienyl-amido complexes, with Ti(IV), via dehalosilylation, 4, 448... 

However, the ready availability of halocyclopropanes has led to extensive studies of their 1,2-dehydrochlorination, and amines are now rarely used as cyclopropene precursors. Although the reaction of 1,1-dichlorocyclopropanes with strong base does in certain situations lead to cyclopropenes, it is frequently the case that the initially formed 1-halocyclopropene does not survive under the reaction conditions, undergoing either addition of a nucleophile to the alkene bond or prototropic shifts followed by further dehydrohalogenation. Two main variations on this method are available which proceed under conditions where further reaction does not, in general, occur, that is 1,2-dehalogenation and 1,2-dehalosilylation. Each of these three alternatives will be considered in turn. 

The reaction is considerably exothermic, and the real temperature at the reaction site may be rather higher than the overall zone temperature. This may explain the difference in products from those obtained in the gas-phase dehalosilylation of 7,7-dichloro-l-trimethylsilylbicyclo[4.1. Ojheptane44. 

The fluoride-promoted dehalosilylation of l-trimethylsilyl-2,2-dihalocyclopropanes provides one of the easiest routes to simple monohalocyclopropenes, the products being trapped by [4 + 2]-addition to furan or diphenylisobenzofuran (DPIBF)121. In the same... 

The dehalosilylation can be carried out in the gas phase over solid tetra- -butylammo-nium fluoride deposited on glass helices, and even 59 can be transferred to a cold finger and trapped with cyclopentadiene, or as a remarkably stable ene-dimer44,128. 

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