2857-97-8 Usage
Chemical Description
Bromotrimethylsilane is a reagent used for the protection of hydroxyl groups in organic synthesis.
Description
Bromotrimethylsilane, also known as TMS-Br, is a clear yellow liquid with a boiling point of 79°C, density of 1.188 g/cm3, and refractive index of 1.4240 at 20°C. It is a versatile reagent in organic synthesis, known for its mild and selective properties in various chemical reactions.
Uses
1. Used in Organic Synthesis:
Bromotrimethylsilane is used as a silylating agent for the protection or deprotection of functional groups selectively in organic synthesis. It acts as a silane blocking agent, which is widely used in the syntheses of drugs.
2. Used in Cleavage of Lactones, Epoxides, and Other Functional Groups:
Bromotrimethylsilane is a mild and selective reagent for the cleavage of lactones, epoxides, acetals, phosphonate esters, and certain ethers. It is also an effective reagent for the formation of silyl enol ethers and can function as a brominating agent.
3. Used in the Formation of Enamines:
Amines react with TMS-Br to form isolable adducts, which react readily with ketones to form enamines under mild conditions.
4. Used in the Synthesis of Adefovir Intermediate:
Bromotrimethylsilane is utilized in the synthesis of adefovir intermediate, which is an important compound in the pharmaceutical industry.
5. Used as a Powerful Silylating Agent:
Due to its reactivity and selectivity, Bromotrimethylsilane is considered a powerful silylating agent in various chemical reactions and applications.
6. Used in Catalysis:
Bromotrimethylsilane is used with Cl3 to catalyze the direct allylation of a variety of alcohols with allyltrimethylsilane, which is an important reaction in the synthesis of complex organic molecules.
Preparation
although many methods are reported,
only a few are provided here: chlorotrimethylsilane undergoes
halogen exchange with either magnesium bromide in Et2O
or sodium bromide in MeCN, which allows in situ reagent
formation (eq 1); alternatively, hexamethyldisilane reacts with
bromine in benzene solution or neat, to afford only TMS-Br
with no byproducts (eq 2).4 TMS-Br may also be generated
by reaction of hexamethyldisiloxane and aluminum bromide
(eq 3).However, it should be noted that the reactivity of in
situ generated reagent appears to depend upon the method of
preparation.
Purification Methods
Purify it by repeated fractional distillation and store it in sealed ampoules in the dark. [McCusker & Reilly J Am Chem Soc 75 1583 1953.] Also fractionate it through a 15-plate column (0.8 x 32cm packed with 1/16in single turn helices of Pt-Ir wire). [Gilliam et al. J Am Chem Soc 68 1161 1946, Pray et al. J Am Chem Soc 70 433 1948, Beilstein 4 IV 4008.]
Check Digit Verification of cas no
The CAS Registry Mumber 2857-97-8 includes 7 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 4 digits, 2,8,5 and 7 respectively; the second part has 2 digits, 9 and 7 respectively.
Calculate Digit Verification of CAS Registry Number 2857-97:
(6*2)+(5*8)+(4*5)+(3*7)+(2*9)+(1*7)=118
118 % 10 = 8
So 2857-97-8 is a valid CAS Registry Number.
InChI:InChI=1/C3H9BrSi/c1-5(2,3)4/h1-3H3
2857-97-8Relevant articles and documents
Redistribution equilibria of substituents between the methyl- and trimethylsilicon moieties
Moedritzer, Kurt,Van Wazer, John R.
, p. 1254 - 1257 (1966)
Scrambling equilibria resulting from the exchange of pairs of monofunctional substituents (halogen, methoxyl, methylthio, and dimethylamino) between the methyl- and trimethylsilicon moieties have been studied by proton nuclear magnetic resonance. Unexpect
Evers et al.
, p. 239,240 (1960)
The First Gallium-Arsenic Compound containing a Single Ga3As Unit: Isolation and Crystal Structure of 3As (thf=tetrahydrofuran)
Wells, Richard L.,Shafieezad, Soheila,McPhail, Andrew T.,Pitt, Colin G.
, p. 1823 - 1824 (1987)
3As (thf=tetrahydrofuran), isolated from the products of the reaction of (Me3Si)3As with GaBr3, has been shown by X-ray crystallographic analysis to be the first example of a compound containing a single Ga3As unit.
-
Eaborn, C. E.
, p. 685 - 686 (1950)
-
C3-Heteroaroyl cannabinoids as photolabeling ligands for the CB2 cannabinoid receptor
Dixon, Darryl D.,Tius, Marcus A.,Thakur, Ganesh A.,Zhou, Han,Bowman, Anna L.,Shukla, Vidyanand G.,Peng, Yan,Makriyannis, Alexandros
supporting information; experimental part, p. 5322 - 5325 (2012/09/07)
A series of tricyclic cannabinoids incorporating a heteroaroyl group at C3 were prepared as probes to explore the binding site(s) of the CB1 and CB2 receptors. This relatively unexplored structural motif is shown to be CB2 selective with Ki values at low nanomolar concentrations when the heteroaromatic group is 3-benzothiophenyl (41) or 3-indolyl (50). When photoactivated, the lead compound 41 was shown to successfully label the CB2 receptor through covalent attachment at the active site while 50 failed to label. The benzothiophenone moiety may be a photoactivatable moiety suitable for selective labeling.
An efficient large-scale synthesis of gemcitabine employing a crystalline 2, 2-difluoro-α-ribofuranosyl bromide
Chang, Young-Kil,Lee, Jaeheon,Park, Gha-Seung,Lee, Moonsub,Park, Chul Hyun,Kim, Han Kyong,Lee, Gwansun,Lee, Bo-Young,Baek, Ju Yuel,Kim, Kwan Soo
experimental part, p. 5687 - 5691 (2010/09/18)
An efficient large-scale synthesis of gemcitabine was achieved without chromatography or fractional crystallization. The key steps include stereospecific conversion of a novel β-ribofuranosyl phosphate into a highly crystalline a-ribofuranosyl bromide and coupling of the α-ribofuranosyl bromide and trime- thylsilyl cytosine to produce a β-nucleoside. p-Phenylbenzoyl group was introduced for the protection of one of hydroxy groups in order to enhance the crystallinity of intermediates. Continuous removal of trimethylsilyl bromide, generated during the coupling reaction, by distillation from the reaction medium substantially enhanced the β-selectivity of the crucial coupling reaction.