Trimethylsilylmethyl iodide

The same technique has been used to react trimethylsilylmethyl iodide and t-butylamine to prepare the corresponding secondary amine.80 Several other examples... 

Nonfunctionalized alkenes such as terminal alkenes are not available on similar treatment of, for example, 2-sulfonylalkanes with bases. However, these have been obtained on alkylation of a-metallo sulfones with trimethylsilylmethyl iodide and subsequent reaction of the resulting -silyl sulfone with... 

It is readily converted to trimethylsilylmethylmagnesium chloride (see [13170-43-9] above) in —90% yield. It reacts with n-BuLi in pentane to give trimethylsilylmethylLi [Sommer et al. J Am Chem Soc 71 2750 1949, which reacts with anhydrous cerium (III) chloride to form trimethylsilylmethyl cerium dichloride. The latter reacts with acyl hahdes to provide bis-p-silylethyl tertiary alcohols that effidently undergo a trimethylchlorosilane-promoted Peterson reaction to generate allylsilanes in high overall yields [Anderson Fuchs Synth Commun 17 621 7987]. It is useful also for Peterson olefination and homologation of aldehydes and ketones via 1,2-epoxysilanes [Lee et al. Tetrahedron 45 5877 7989]. Trimethylsilylmethyl bromide [18243-41-9] has M 167.1, b 115.5 /atm, 1.17, Up 1.444 [Beilstein 4 IV 3878], and trimethylsilylmethyl iodide [4206-67-1] has M 214.1, h 139-141 /atm, df 1.433, ng 1.491 [Beilstein 4 IV 3878], and both should be stored in the dark. 

An example of fluoride induced conversion is of a hetaryl 2-(trimethylsilyl)ethyl sulfone to the sulfinic acid via protonation of the sulfinate anion. The treatment of a collection of arenesulfinate anions, obtained from the corresponding 2-(trimethylsilyl)ethyl sulfones, with H2NOSO3H gave aryl sulfonamides in 50-85% yield (eq 13). In this case and elsewhere, the aryl 2-(trimethylsilyl)ethyl sulfones are prepared through the deprotonation of aryl methyl sulfones and quenching of the a-sulfonyl carbanion with trimethylsilylmethyl iodide, or the less expensive trimethylsilylmethyl chloride. Such a protocol is complementary to the oxidation of 2-(trimethylsilyl)ethyl thioethers. 

Although 1, -elimination of o xylene polyhalides with sodium iodide, zinc, copper, or iron metal is a fundamental method for the formation of o-xylylene intermediates, it is difficult to carry out the reaction under mild conditions such as at room temperature. o Trimethylsilylmethyl)-benzyltrimethylammonium halides were devised for this purpose and were shown to generate the o-xylylene at room temperature. However, we have successfully generated o-xylylene at room temperature by the reaction of a, 0,-dibromo o-xylene with metallic nickel(51). The Diels-Alder reaction of... 

Alkylation of 3,5-diaryl-l,2,4-thiadiazoles 22 with trimethylsilylmethyl triflate, in contrast to methyl iodide, occurs at N-2 to afford the salt 23 (Equation 5) and the quaternization at N-2 was confirmed by analysis of the 1SN NMR spectrum <1999J(P1)1709>. 

An efficient method for the generation of oquinodimethanes via desilylation reaction involves treatment of a 2-[(trimethylsilylmethyl)benzyl]trimethylarmnonium iodide with fluoride ion (equation 31)64. This reaction was applied by Saegusa and coworkers for the synthesis of estrone in which an intramolecular Diels-Alder reaction of an o-quinodimethane, generated in situ, served as the key reaction (equation 32)65. 

Allylsilanes. A general synthesis of allylsilanes involves alkylation at the imposition of an allylic alcohol substituted at the 7-position by a trimethylsilyl group or at the a-position by a trimethylsilylmethyl group with an organolithium compound mediated by this phosphonium iodide (l).2... 

Hydroxymethyl-3-allyltrimethylsilane. 2-(Trimethylsilylmethyl)-3 acetoxy-1 -propene. 2-(Trimethylsilyl)n]ethylallyl iodide. 

Trimethylsilyl)methylallyl iodide, 579 2-Trimethylsilylmethyl-1,3-butadiene, 580 Trimethylsilylmethyllithium, 581 Trimethylsilylmethylmagnesium chloride, 58,... 

It has been demonstrated that TMS iodide (in combination with cesium fluoride) or TMS triflate in various solvents (THF, MeCN, HMPA) are excellent reagents to promote the generation of azomethine ylids from A-methoxymethyl-A-(trimethylsilylmethyl)aIkyl-amines and their cycloaddition to electron deficient alkenes with yields ranging from moderate to nearly quantitative. The geometry of the double bond in the alkene is preserved in the cycloadduct.410... 

Ligand exchange reactions of monodentate amides, iodides, or alkoxide complexes with other amides, alkoxides as well as sulfides, and carbon ligands has been documented [23,25]. A rather unique reaction of a trimethylsilylmethyl ligand bound to a chromium nitride has been reported thus, reaction of tert-butyl isocyanide with 52 is reported to furnish 53 (Eq. (17)). 

ISOPREPENYLATION Aluminum chloride. Aluminum chloride-Potassium pheno-xide. Carbon disulfide-Methyl iodide. 2-Trimethylsilylmethyl-l, 3-butadiene. 2-Trimethylsilylmethylenecyclobutane. 

Use of trimethylsilylmethyl triflate enables the effective formation of intermediate iminium salts in the reaction mixture because the counteranion, triflate ion, is nonnucleophilic both to carbon and silicon atoms. N-Silyl-methylation can also be performed with other alkylating agents, such as silymethyl chloride, bromide, and iodide. However, the resulting iminium salts desilylate immediately after they are formed by the attack of the halide counteranions, leading to a serious decomposition of the requisite iminium intermediates. The final step of desilylation generating azomethine ylides is effected by a fluoride anion which is selectively nucleophilic to a silicon atom. 

The synthesis of the tetrahydrobenzo A]thiophenes is outlined in Scheme 2.4. A Grignard-reaction of 50 with ClMgCH2SiMe3 followed by quaternisation with methyl iodide gave the 3-(trimethylammoniummethyl)-2-(trimethylsilylmethyl)thiophene 52, which is the precursor of... 

Trimethylsilylmethyl)triphenylarsonium Tetraphenylborate (4) A solution of chloro(trimethyl)silane (4.1 g, 38 mmol) in EtjO (40 mL) was added to a solution of triphenylarsonium methylide, prepared from methyltriphenylarsonium iodide (11.2 g, 25 mmol) and PhLi (25 mmol) in EtjO (230 mL). The mixture was stirred at — 70 °C for 1 h and at 20 °C for 2 h. The white precipitate was filtered off, washed several times with EtjO, dissolved in MeOH (30 mL), and sodium tetraphenylborate (8.5 g, 25 mmol) in MeOH (20 mL) was added. After separation, the crude product was recrystallized (1,2-dichloroethane/EtOAc/ EtjO) yield 12.1 g (68%) mp 174-176°C. 

Alternatively, the o-benzoquinodimethane may be generated by fluoride-induced 1,4-elimination from trimethyl[2-(trimethylsilylmethyl)benzyl]ammonium iodide (13a). Interception with l-bromo-2-chlorocyclopropene gave the adduct 15a in 38% yield.Tetrahalocy-clopropenes were, however, unreactive. This method of o-quinodimethane generation has also been applied to pyridine derivatives, and provided a short route to l//-cyclopropa[g]quino-linc (16b).The interception was unsuccessful when the approach was applied to cyclo-propaisoquinoline. ... 

The sole synthesis of hybridalactone (73) is due to Corey at Harvard. The synthesis involved the use of the novel bicyclo[2.2.2]octyl ortho esters beginning with 62 (Scheme 3.5). This material, obtained from 5-hexynoic acid, was converted via the homologous trimethylsilylmethyl acetylene into allenic iodide 63 in 75% overall yield. 

Eliminations have involved l,2-bis(bromomethyl)-heterocycles with iodide, ortho-(trimethylsilylmethyl) heterenemethyl ammonium salts, ort/w-(trimethylsilylmethyl) heterenecarbinol mesylates, each with a source of fluoride, and ort/ (9-(tri-n-butylstannylmethyl) heterenecarbinol acetates with a Lewis acid. ... 

The sulfonium ylide obtained from dimethyl(trimethylsilylmethyl)sulfonium iodide by deprotonation with 1-methylpropyllithium reacts with 2-cyclohexenone to provide 7-(trimethylsilyl)-bicyclo[4.1 0]heptan-2-one with good exo selectivity10. The diastereofacial selectivity of the ylide is also high, as demonstrated by the conversion of the chiral substituted 2-cyclohexenone into cyclopropane derivative 12. 

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