Electrogenerated Acid-Catalyzed Reactions of Acetals, Aldehydes, and Ketones with Organosilicon Compounds, Leading to Aldol Reactions, Allylations, Cyanations, and Hydride Additions
electrogenerated acid (EG acid) in the silicon-mediated acid-catalyzed reactions; e.g., aldol reactions, allylations, cyanations, and hydride additions is described. The aldol reaction of acetals 1 with enol trimethylsilyl ethers 3 and 1,2-bis(trimethylsiloxy)alkenes 4 gives the corresponding adducts 5 and 6, respectively. The reaction proceeds smoothly with EG acid derived from perchlorate salts such
Organotin perchlorates as gentle Lewis acid catalysts in Mukaiyama reaction
作者:Jian-xie Chen、Junzo Otera
DOI:10.1016/s0040-4020(97)00995-2
日期:1997.10
aldehydes, an electron-donating group increases the reactivity of aldehyde while the reverse is true with an electron-withdrawing group. These are opposite to the reactivity order in nucleophilic addition to free carbonyls. In contrast to ketene silyl acetal, enol silyl ethers derived from ketones are not activated by organotin perchlorates. Thus, these two enol silyl ethers can be discriminated from each
are performed simultaneously on separate reaction sites, has been advanced. Ketones/α,β-enones and aldehydes/acetals are able to react selectively with different silyl nucleophiles in parallel. The subtle differentiation between the substrates possessing similar reactivities has recourse to the strong preference of ketene silyl acetal for ketones/α,β-enones.