A catalytic amount of tris(p-bromophenyl)aminium hexachloroantimonate promoted the substitution reactions of dimethylacetals with various silylatednucleophiles through an electron transfer mechanism. Silyl compounds include silyl enol ether, ketene silyl acetal, and allylsilane. One methoxy group of the substrates was effectively substituted by nucleophiles to form carbon-carbon bonds.
IMMOBILIZED CATALYST DIRECTED TO SYNTHETIC CONTROL. CROSS-ALDOL REACTION
作者:Teruaki Mukaiyama、Hiroshi Iwakiri
DOI:10.1246/cl.1985.1363
日期:1985.9.5
Cross-aldol adducts are stereoselectively formed in good yields by treating acetals or aldehydes and silyl enol ethers in a heterogeneous system with a catalytic amount of polymer-supported trityl perchlorate.
In the presence of a catalytic amount of tritylperchlorate, silyl enol ethers and ketene silyl acetals react with acetals and methyl orthoformate to give the corresponding aldol-type addition products in good yields.
Catalytic amounts of triarylpyrylium saltsphotochemically and thermally promoted the substitution reactions of dimethyl acetals with silylated nucleophiles.
New Application of Solid Acid to Carbon–Carbon Bond Formation Reactions: Clay Montmorillonite-Catalyzed Aldol Reactions of Silyl Enol Ethers with Aldehydes and Acetals
作者:Motomitsu Kawai、Makoto Onaka、Yusuke Izumi
DOI:10.1246/bcsj.61.1237
日期:1988.4
A new attempt of utilizing solid acid to the cross aldol reaction of silylenolethers with aldehydes or acetals has been investigated. Among solid acids employed, the reaction is promoted most effectively by a catalytic amount of aluminium ion-exchanged montmorillonite (Al-Mont). Simple diastereoselection is significantly sensitive to the nature of the reaction solvent used in the Al-Mont-catalyzed