Silane dimethylamino trimethyl

Silan (Dimethylamino-thiocarbo-nyl)-trimethyl- E19d, 663 (H -> Li + R3Si —Cl)... 

A soln. of trimethylsilyl triflate in methylene chloride added dropwise to a soln. of benzaldehyde and dimethylamino(trimethyl)silane in the same solvent under N2, and the mixture stirred at room temp, for 15 min - bis(dimethylamino)methylbenzene. Y 93%. Reaction is high-yielding and general for both ar. and aliphatic aldehydes (the latter with BU4NF) the intermediate 1,1-siloxyamines have been characterized. F.e.s. P. Aube et al.. Bull. Soc. Chim. France 1988, 1009-14 from alkylidenephosphoranes via selenaldehydes cf. K. Okuma et al., Chem. Letters 1988, 1145-8. 

The method has been further improved." Trimethyl(perfluoroalkyl)silanes RpTMS (Rp = c, -C, perfluoroaliphatic groups) are prepared by reaction of perfluoroalkyl halides RpX (X = Br, I) with chlorotrimethylsilane in the presence of tris(dialkylamino)phosphanes in acetonitrile. For example, chlorotrimethylsilane was treated with bromotrifluoromethane and tris(diethylamino)phosphane in acetonitrile at — 40"C for 1 hour to give trimethyl(trifluo-romethyl)silane in 90% yield. Bis(dimethylamino)(trifluoromethyl)silane is available from the reaction of chlorobis(dimethylamino)silane with the system bromotrifluoromethane/tris-(diethylamino)phosphane, while trichloro(trifluoromethyl)silane is prepared by nucleophilic trifluoromethylation of tetrachlorosilane with bromotrifluorornethane/tris(diethylamino)phos-phane. " ... 

C —Br and C l bond polarization in perfluoroalkyl- and polyfluoroaryl-containing derivatives may be promoted by reagents other than phosphorus derivatives. When tetrakis-(dimethylamino)cthene is treated with bromotrifluoromethane or trifluoroiodomethane in the presence of chlorotrimethylsilane under similar conditions" only traces of trimethyl(trifluoro-methyl)silane are obtained, but dimethylbis(trifluoromethyl)silanecan be prepared from trifluoroiodomethane and dichlorodimethylsilane in 63 "/u yield. " ... 

When activated by anionic catalysts [potassium fluoride, cesium fluoride, tctraalkylammonium fluorides, tris(dimethylamino)sulfonium difluorotrimethylsilicate, phosphazenium, hexa-methylpiperidinium and cobaltoccnium fluorides, tetrabuiylammonium difluoro(triphenyl-silyl)silicatc. the complex tetrakis(dimethylamino)ethene/pcrfluoropropene, ammonium (and phosphonium) periluorocyclobuianc ylides], trimethyl(perfluoroalkyl)silanes will generate C-Rp bonds from carbon-halogen bonds. 

Trimethyl(trifluoromethyl)silane is easily fluorodesilylated by tris(dimethylamino)sulfonium difluorotrimethylsilicate [TASF(Me)], tetrabutylammonium fluoride, or tris(diethylamino) (methylamino)phosphonium hydrogen difluoride and. if arenesnlfonyl fluorides are used to trap the trifluoromethyl anion, trifluoromethyl sulfones are formed in high yield. Tris(diethyl-amino)(methylamino)phosphonium phenolate is also an effective catalyst for this reaction, but TASF(Me) is favored as it can achieve the quantitative transformation of ArS02F into aryl trifluoromethyl sulfones.115-117... 

MTS, l-methoxy-2-methyl-l-propenoxyl trimethyl silane TBAF, tetra-n-butylammonium [fluoride] TASHF2, tris(dimethylamino)sulfonium [bifluoride] TBABOAc, tetra-n-butylammonium biacetate TBAB, tetra-n-butylammonium benzoate (Ph4P)2HF2, tetraphenylphosphonium bifluoride. 

---