Organosilane Reduction of Aldehydes

Et3SiH, TMSOTf, c-C6HnOTMS, CH2C12 0° 2 h c-C6Hn (100f 334 

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Supplemental References for Table 11. Organosilane Reduction of Aldehydes... 

The organosilane reduction of acid chlorides to aldehydes has been accomplished in high yields with the use of the pentacoordinated organosilane 60 (Eq. 137).107 This transformation has been reported to occur with tribenzylsilane and triethylsilane, but yields were not reported.285,286... 

Supplemental Reference for Table 15. Organosilane Reduction of a,p -Unsaturated Aldehydes... 

Reductive Amidation of Aldehydes. The reductive amidation of aldehydes using an organosilane as the reducing agent has been realized. Benzaldehyde reacts over a 74-hour period with triethylsilane and acetonitrile in 75% aqueous sulfuric acid at room temperature to produce an 80% isolated yield of N-benzylacetamide (Eq. 169).313 Octanal fails to react under the same conditions.313 Reductive amidation of aldehydes also occurs with the reagent combination Et3SiH/TFA/primary amide (Eq. 170).326... 

Reduction to Alcohols. The organosilane-mediated reduction of ketones to secondary alcohols has been shown to occur under a wide variety of conditions. Only those reactions that are of high yield and of a more practical nature are mentioned here. As with aldehydes, ketones do not normally react spontaneously with organosilicon hydrides to form alcohols. The exceptional behavior of some organocobalt cluster complex carbonyl compounds was noted previously. Introduction of acids or other electrophilic species that are capable of coordination with the carbonyl oxygen enables reduction to occur by transfer of silyl hydride to the polarized carbonyl carbon (Eq. 2). This permits facile, chemoselective reduction of many ketones to alcohols. 

Table 14. organosilane reductive amination of aldehydes and ketones... 

Table 14. Organosilane Reductive amination of aldehydes and Ketones (Continued)...

Supplemental References for Table 14. Organosilane Reductive Amination of Aldehydes and Ketones... 

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