Trimethylsilylacetonitrile (TMSAN)

Abstract

(A) The condensation of TMSAN with ketones in the presence of the catalytic t-Bu-P4 base to give cyanoalkenes has been reported;3 title compounds were prepared in a 63-80% yield. The reaction was also extended to the condensation of TMSAN with N-arylformanilides (ArNRCHO) in the preparation of enamine derivatives. (Chemical Equation Presented). (B) The addition of TMSAN to the carbonyl group of benzaldehyde catalyzed by KF/Al2O3 in THF allows the preparation of 3-phenyl-3-(trimethylsilyloxy)propionitrile as the major product (85%), together with cinnamonitrile (15%). A change of the solvent to DMF leads to the α,β-unsaturated nitrile as main product (61%).4 (Chemical Equation Presented). (C) Langer and co-workers reported a one-pot cyclization of epibromohydrin (EBH) with TMSAN in the presence of a strong base and catalyzed by a Lewis acid to form trimethylsilylcyano cyclopropane with excellent diasteroselectivity (E/Z > 98:2) and moderate yield (65%). 5 (Chemical Equation Presented). (D) Recently, 2-(2-cyanoethyl) aziridines were obtained by treatment of TMSAN with an equimolecular amount of n-BuLi followed by the addition of 1-arylmethyl-2-(bromomethyl)-aziridines. 6 Title compounds were obtained in moderate yield (41-65%). (Chemical Equation Presented). (E) TMSAN has been used as a nucleophile to open the acetal ring in sugar spiroketals. The nucleophilic attack of TMSAN on the anomeric carbon can take place either through the nitrogen atom or through the methylenic carbon7 to give a spironucleoside or a spiro-C-glycoside, respectively. (Chemical Equation Presented). (F) There are a few reports of cyanomethylation of aldehydes and ketones using TMSAN as nucleophile. Suto et al. have developed a copper fluoride catalyzed addition to the carbonyl group with high yields.8 (Chemical Equation Presented). (G) β-Amino nitriles can be obtained by the condensation between chiral N-(tert- butylsulfonyl)imines and TMSAN in the presence of a Lewis base with excellent diasteroselectivity.9 Optimization of the reaction conditions by changing the Lewis base, temperature, and solvent showed that the best yields and diasteroisomeric ratios were obtained when PhONn-Bu4 was used as a Lewis base in THF at -78°C. (Chemical Equation Presented). (H) Wu and Hartwig described the monoarylation of nitriles by means of the coupling of TMSAN with aryl halides in the presence of palladium catalysts and zinc fluoride. 10 (Chemical Equation Presented). (I) A singular reaction of transannulation of pyridotriazoles with TMSAN in the presence of Rh 2(OAc)4 to afford a N-fused imidazopyridine was described by Chuprakov et al.11 Rhodium-catalyzed transannulations of 1-sulfonyl triazoles were recently reported by the same group.12 (Chemical Equation Presented). (J) Nakao et al. reported the Ni-catalyzed carbocyanation of 4-octyne with TMSAN in the presence of a Lewis acid (LA) to give a highly substituted allylsilane in modest yield (29%).13 (Chemical Equation Presented).