synthesizing the target molecules. The perfect chemoselectivity between aromatic and aliphatic aldehydes is difficult to achieve by the previous methods. The aromatic aldehyde-selective nucleophilic addition in the presence of aliphatic aldehydes was newly accomplished. Namely, the aromatic aldehyde-selective nucleophilic addition using arenes and allyl silanes proceeded in the presence of trialkylsilyl
Montmorillonite K10 clay-catalyzed synthesis of homoallylic silyl ethers: an efficient and environmentally friendly Hosomi–Sakurai reaction
作者:Matthew R. Dintzner、Yawo A. Mondjinou、Barrett Unger
DOI:10.1016/j.tetlet.2009.09.051
日期:2009.12
Aromatic aldehydes react with allyltrimethylsilane in the presence of activated Montmorillonite K10 clay to give homoallylic silyl ethers in good to excellent yields.
Highly atom economical uncatalysed and I2-catalysed silylation of phenols, alcohols and carbohydrates, using HMDS under solvent-free reaction conditions (SFRC)
作者:Marjan Jereb
DOI:10.1016/j.tet.2012.03.040
日期:2012.5
An uncatalysed silylation of phenols, regardless on the aggregate state and nature of the substituents with 0.55 equiv of HMDS under solvent-free reaction conditions (SFRC) at room temperature is reported. Sterically hindered phenols, carbohydrates and most of the alcohols additionally required a catalytic amount (up to 2 mol%) of iodine. The reaction protocol is very simple; obtaining a pure product, particularly of uncatalysed reactions, was frequently a completely solvent-free process. (C) 2012 Elsevier Ltd. All rights reserved.
Mesoporous aluminosilicate-catalyzed allylation of carbonyl compounds and acetals
A mesoporous aluminosilicate (Al-MCM-41) was found to be an effective heterogeneous catalyst for the reaction of both carbonyl compounds and acetals with allylsilanes to afford the corresponding homoallyl silyl ethers and homoallyl alkyl ethers, respectively. Both the mesoporous structure and the presence of aluminum moiety were indispensable for the high catalytic activity of Al-MCM-41. Moreover, Al-MCM-41 could catalyze the reaction of acetals chemoselectively in the presence of the corresponding carbonyl compounds. The solid acid catalyst Al-MCM-41 could be recovered easily by filtration and could be reused three times without a significant loss of catalytic activity. (C) 2011 Elsevier Ltd. All rights reserved.
Mesoporous aluminosilicate-catalyzed allylation of aldehydes with allylsilanes
Mesoporous aluminosilicate (Al-MCM-41) was found to catalyze the allylation of both aromatic and aliphatic aldehydes with allylsilanes although amorphous silica-alumina or mesoporous silicates (MCM-41, SBA-15) Could not catalyze the reaction under the same reaction conditions. The solid acid catalyst Al-MCM-41 could be reused three times without significant loss of activity. (C) 2009 Elsevier Ltd. All rights reserved.