The presence of the heterogeneous mesoporous Al-MCM-41 catalyst remarkably accelerated the cyanosilylation of various aldehydes and ketones with trialkylsilyl cyanide, giving the corresponding cyanohydrin silyl ethers in quantitative yields under mild reaction conditions.
The Addition of Trimethylsilyl Cyanid to Carbonyl Compounds Using Yb(OTf)<sub>3</sub> as Lewis Acid Catalyst
作者:Yang Yang、Dong Wang
DOI:10.1055/s-1997-1071
日期:——
Yb(OTf)3 was found to be an effective catalyst in the addition of TMSCN to various carbonyl compounds. Highly chemoselective process was observed in the reactions of α-keto aldehyde acetals. Catalyst Yb(OTf)3 is tolerant to the hydroxy group of glyoxylate hydrates used. Catalytic diastereoselective trimethylsilylcyanation of chiral aldehydes and cyanation of glyoxylate hydrates can be carried out under mild condition with moderate de.
Inorganic/Organic Salts as Heterogeneous Basic Catalysts for Cyanosilylation of Carbonyl Compounds
作者:Xiaoming Feng、Bin He、Yan Li、Guolin Zhang
DOI:10.1055/s-2004-829569
日期:——
The addition of TMSCN to carbonyl compounds catalyzed by K2CO3 as heterogeneous catalyst gave the corresponding cyanohydrin trimethylsilyl ethers from 20 minutes to 24 hours with 62% to 99% yields without solvent at room temperature. Moreover, it was found that chiral organic salts as heterogeneous catalysts also can catalyze the asymmetric version and afford the corresponding products with up to 99% yield and 12.4% ee.
for the synthesis of 0-substituted cyanohydrins from aldehydes and ketones, in the absence of solvent, employing minimum amounts of the corresponding cyanides has been optimised. Aldehydes react more rapidly than ketones using triethylamine as catalyst offering in both cases almost quantitative yields of the corresponding O-trimethylsilyl, O-methoxycarbonyl, O-benzoyl and O-acetyl cyanohydrins.
Phenolic<i>N</i>-Oxide as a Highly Efficient Organocatalyst for Cyanosilylation of Ketones
作者:Xiaoming Feng、Yan Li、Bin He、Guolin Zhang
DOI:10.1055/s-2004-829072
日期:——
The use of an inexpensive, easy to handle and readily available chemical, 5 mol% phenolic N-oxide, alone as a catalyst for cyanosilylation of ketones gave the corresponding products in 78-99% yield with reaction times of 0.5-16 hours.