Imines triethylsilane

The tetrachloroferrate or tetralluoroborate salts of alkylated alkyl- or aryl-nitriles (nitrilium ions) are reduced to imines with triethylsilane. Subsequent hydrolysis of the intermediate imines leads to aldehydes in good yields, thus providing an excellent overall route to aldehydes from nitriles (Eq. 338).28,562... 

Weinreb and coworkers have also developed a simple one-pot procedure for reductive sulfonamidation of both aromatic and aliphatic aldehydes [14], Again using the Kresze methodology an aldehyde could be converted to a Lewis acid-complexed N-tosyl imine which in the presence of triethylsilane was reduced to a sulfonamide in good yields [Eq. (29)]. 

Imines are reduced by triethylsilane to their amines when the proper Ir orNi catalysts areemployed. Non-metal-mediated reductions of C=N groups by EtsSiH are also possible. Among these, the trifluorosulfonic acid promoted reductive amidation of aliphatic and aromatic aldehydes with EtsSiH is an excellent way to mono (V-alkylate aliphatic and aromatic amides, thioamides, carbamates, and ureas (eq 26). It is also worth noting that trifluorosulfonic acid/EtsSiH reduces acyl- and tosylhydrazones to hydrazines and 2-aminopyrimidines to 2-amino-dihydro-or 2-aminotetrahydropyrimidines (eq 27). ... 

Another example of a single-pot-type reaction involved replacement of the carbon nucleophile with aniline 76, thus affording the a,P-unsaturated imine 77. Both aromatic and alkyl amines afford the desired imine in good-to-excellent yields. The use of triethylsilanes afforded greater Z E ratios in 77.f l... 

Silicon being more electropositive than hydrogen (Pauling electronegativities Si 1.90, H 2.20), silanes with Si-H bonds can reduce a variety of functional groups such as carbonyl compounds, imines, and even alcohols by transferring a hydride anion. Triethylsilane is a common reagent, and typical reaction conditions also include either a Brpnsted or a Lewis acid, as shown below for the reduction of a ketone ... 

The disc-shaped plastic micoreactors, termed microcapillary films (MCFs), contain 19 parallel microchannels, each with a mean internal diameter of 142 10 pm. The material was prepared using a melt extrusion process from an ethylene-vinyl alcohol copolymer (EVOH) [28]. Immobilization of palladium(0) on the wall surface inside the MCFs was performed by simple chemical deposition techniques (Scheme 7.3). The palladium-coated capillaries were used for transfer hydrt enation of ketones, imines, nitro compounds, alkenes, and alkynes with triethylsilane under flow conditions [29]. Microcapillaries whose inside surfaces were coated with copper or gold were also utilized for the continuous-flow reactions [30]. 

The quest for tin-free reductive methods led the same authors to develop the use of indium(lll) hydride ClalnH, generated in situ from triethylsilane and InCla. Aromatic and aliphatic azides as well as sulfonyl azides and acyl azides are reduced in moderate to excellent yield to the corresponding amines and amides. Azido nitriles are efficiently converted to the pyrrolidin-2-imines (Scheme 8.45). 

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