Trimethylsilyl cyanide reaction with

Because allyltrimethylsilane 82 or benzyltrimethylsilane 83 can be regarded as combinations of the hard trimethylsilyl cation and the soff allyl or benzyl anions, pyridine N-oxide 860 reacts with excess 82 or 83 in the presence of catalytic amounts of tetrabutylammonium fluoride di- or trihydrate in THF to give 2-allyl-or 2-benzylpyridines 948 and 950 [60]. The general reaction of silicon reagents such as 82 and 83 or of trimethylsilyl cyanide 18 with fluoride to generate allyl or... 

Two groups simultaneously found that trimethylsilyl cyanide reacts with disubstituted acetylenes in the presence of a Pd catalyst to form silylated 2-amino-5-cyanopyrroles 194 or 195 [133, 134], These reactions are run neat and a variety of Pd species are successful in this transformation [133]. In the case of unsymmetrical diaryl acetylenes, the reaction is not regioselective [134],... 

Hydride abstraction from dienyl tricarbonyl iron complexes furnishes cationic dienyl tricarbonyl iron complexes. For example, reaction of the diene-iron tricarbonyl complex (115) with triphenyhnethyl hexafluorophosphate followed by trimethylsilyl cyanide furnished with excellent regio- and stereoselectivity a new diene iron tricarbonyl complex (116) (Scheme 170). Excellent regio- and stereoselectivity is seen upon reaction of the cationic complex (116) with trimethylsilyl cyanide (TMS-CN) (Scheme 170). Reduction of the nitrile affords a spirocyclic lactam complex. Intramolecular cyclization of in situ formed enols furnishes spirocyclic compounds again with excellent stereoconfrol (Scheme 171). An interesting example of hydride transfer from a cyclohexadiene ring to a pendant aldehyde followed by nucleophilic addition is seen in Scheme 172. 

Trimethylsilyl cyanide reacts with diphenylcyclopropenone in the presence of Fe2(CO)9 or PPh3 as catalyst to give the aminofuran derivative 73 (40-60%) (Eq. (10)). Other phosphines and transition metal phosphine complexes are effective catalysts. A similar reaction was achieved using cycloheptenocyclopropenone. Desilylprotonation of compound 73 was achieved in hot MeOH containing a trace of p-TsOH, but the primary amine was trapped in situ as a cycloadduct without isolation (87JOC4408). 

In contrast, the reaction of trimethylsilyl cyanide (Me3SiCN) with substituted cyclohexadienyl salts (39), yielding cyano-cyclohexadiene adducts (40), follows the unusual rate law (13) in which there is a zero-order dependence on the... 

Allylalion of the alkoxymalonitrile 231 followed by hydrolysis affords acyl cyanide, which is converted into the amide 232. Hence the reagent 231 can be used as an acyl anion equivalent[144]. Methoxy(phenylthio)acetonitrile is allylated with allylic carbonates or vinyloxiranes. After allylation. they are converted into esters or lactones. The intramolecular version using 233 has been applied to the synthesis of the macrolide 234[37]. The /i,7-unsaturated nitrile 235 is prepared by the reaction of allylic carbonate with trimethylsilyl cyanide[145]. 

The reaction of phenylmethylenecyclopropane with trimethylsilyl cyanide catalyzed by PdCl2 affords the allylsilane 81 in 71% yield[63]. 

The reaction works well with primary alkyl halides, especially with allylic and benzylic halides, as well as other alkyl derivatives with good leaving groups. Secondary alkyl halides give poor yields. Tertiary alkyl halides react under the usual reaction conditions by elimination of HX only. Nitriles from tertiary alkyl halides can however be obtained by reaction with trimethylsilyl cyanide 4 ... 

Interestingly, the diastereofacial selectivity can be reversed in the Strecker reaction of aldimines derived from galactosylamine 1 by simply changing the solvent. When the reaction of trimethylsilyl cyanide with the Schiff bases 2 catalyzed by zinc chloride, is carried out in chloroform instead of 2-propanol, there is a preferred formation of the (.S)-amino nitrile diastereomers63. 

A completely different way of preparing isocyanides involves the reaction of epoxides or oxetanes with trimethylsilyl cyanide and zinc iodide, for example, ... 

Thus removal of water from classical rather inactive fluoride reagents such as tetrabutylammonium fluoride di- or trihydrate by silylation, e.g. in THF, is a prerequisite to the generation of such reactive benzyl, allyl, or trimethylsilyl anions. The complete or partial dehydration of tetrabutylammonium fluoride di- or trihydrate is especially simple in silylation-amination, silylation-cyanation, or analogous reactions in the presence of HMDS 2 or trimethylsilyl cyanide 18, which effect the simultaneous dehydration and activation of the employed hydrated fluoride reagent (cf, also, discussion of the dehydration of such fluoride salts in Section 13.1). For discussion and preparative applications of these and other anhydrous fluoride reagents, for example tetrabutylammonium triphenyldifluorosilicate or Zn(Bp4)2, see Section 12.4. Finally, the volatile trimethylsilyl fluoride 71 (b.p. 17 °C) will react with nucleophiles such as aqueous alkali to give trimethylsilanol 4, HMDSO 7, and alkali fluoride or with alkaline methanol to afford methoxytri-methylsilane 13 a and alkali fluoride. 

Reactions of Heterocyclic N-Oxides with Trimethylsilyl Cyanide, Trimethylsilyl Azide, Trimethylsilyl Isothiocyanate, and Trimethylsilyl Halides... 

Reactions of Nitrones and Aliphatic N-Oxides with Trimethylsilyl Cyanide 161... 

Verkade and co-workers have shown the usefulness of their phosphazanes in various stoichiometric as well as catalytic reactions <1999PS(144)101>. Compound 290 was used to promote the cyanohydration of benzaldehyde with trimethylsilyl cyanide (TMSCN). The cyanohydrin was isolated in 95% yield, but no enantioselectivity was noticed <2002JOM(646)161>. Compounds 291 and 292 were attached to dendrimers and shown to be effective in the catalysis of Michael reactions, nitroaldol reactions, and aryl isocyanate trimerizations <2004ASC1093>. 

Treatment of a-(benzotriazol-l-yl)alkyl thioethers 831 with ZnBr2 weakens the bond with benzotriazole, and the obtained complex 832 may partially dissociate to thionium cation 835 that can be trapped by even mild nucleophiles. Thus, trimethylsilyl cyanide added to the reaction mixture causes substitution of the benzotriazole moiety by the CN group to give a-(phenylthio)carbonitrile 834. In a similar manner, treatment with allylsilane leads to y,S-unsaturated thioether 833. Addition of species 835 to the double bond of a trimethylsilyl ot-arylvinyl ether followed by hydrolysis of the silyloxy group furnishes (i-(phenylthio)alkyl aryl ketones 836 (Scheme 132) <1996TL6631>. 

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