Transformations cyanotrimethylsilane

Miscellaneous Transformations. Cyanotrimethylsilane effects the transformation of acyl chlorides to acyl cyanides, a-chloro ethers and a-chloro thioethers to a-cyano ethers and a-cyano thioethers (eq 19), t-butyl chlorides to nitriles (eqs 20 and 21), 1,3,5-trisubstituted hexahydro-l,3,5-triazines to amino-acetonitriles, the cyanation of allylic carbonates and acetates (eqs 22 and 23), and the formation of aryl thiocyanates from aryl sulfonyl chlorides and sulfinates. The reagent has been used effectively in peptide synthesis and in a range of other synthetic applications. " ... 

A simple one-pot procedure for the transformation of tertiary alkyl chlorides into the corresponding nitriles has been developed. This reaction involves the treatment of the alkyl chloride with cyanotrimethylsilane in the presence of tin(IV) chloride and occurs in good yields at room temperature (equation 40). This procedure has also been successful in the preparation of bridgehead nitriles356. 

Aldehydes and ketones are readily transformed into the corresponding cyanohydrin trimethylsilyl ethers when treated with cyanotrimethylsilane in the presence of Lewis acids (eq 1), triethylamine, or solid bases such as Cap2 or hydroxyapatite. The products can be readily hydrolyzed to the corresponding cyanohydrins. The cyanosilylation of aromatic aldehydes can be achieved with high enantioselectivity in the presence of catalytic amounts of a modified Sharpless catalyst consisting of titanium tetraisopropoxide and L-(+)-diisopropyl tartrate (eq 2). Catalysis with chiral titanium reagents yields aliphatic and aromatic cyanohydrins in high chemical and optical yields... 

Addition to Carbonyls, Imines (Strecker-type Reactions), and Heteroaromatic Rings (Reissert-type Reactions). Cyanohydrin trimethylsilyl ethers are of significant synthetic interest as they can be transformed into a variety of multifunctional intermediates. Aldehydes and ketones can be enantioselectively converted to cyanohydrin trimethylsilyl ethers when treated with cyanotrimethylsilane in the presence of a Lewis acid and a chiral ligand. Enantioselective and/or diastereoselective formation of cyanohydrins and their derivatives has been reported and most of these reactions involve chiral ligands and metal catalysts containing Ti (eq 24), Sm (eq 25), and A1 (eq 26). ... 

Excellent enantioselectivity has also been achieved in the reaction between imines and cyanotrimethylsilane, which provides an effective synthesis of chiral a-amino acids. Ti-catalyzed reactions using a chiral tripeptide Schiff base have been developed to realize such transformations (eq 30). In addition, a combination of 2,2 -biphenol and Cinchonine as chiral ligands has been employed to effect such reactions (eq 31). An enantioselective route was also developed for the conversion of readily prepared... 

Miscellaneous Transformations. The hypervalent iodine(III) reagent phenyliodine bis(trifluoroacetate) (PIFA) mediates the selective cyanation reaction of a wide range of electron-rich heteroaromatic compounds such as pyrroles, thiophenes, and indoles under mild conditions (eq 42). Nonactivated arylalkenes are effectively converted to tertiary benzylic nitriles in the presence of triflic acid and cyanotrimethylsilane (eq 43). ... 

Cyanotrimethylsilane has found extensive use as a reagent for a variety of synthetic transformations, and an improved synthesis has been described. The preparation of silylated cyanhydrins has also been improved in a two-stage one-pot synthesis which utilises cyanotrimethylsilane, prepared without isolation and prior to the addition of the carbonyl component (Scheme 24). ... 

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