A mesoporous aluminosilicate (Al-MCM-41) was found to be an effective heterogeneous catalyst for the reaction of both aldehydes and acetals with silylenolethers or ketene silylacetals to give the corresponding aldol adducts in moderate to high yields. The remarkable high catalytic activity of Al-MCM-41 over amorphous silica-alumina and aluminum-free mesoporous silicate was observed in the reaction
Photocatalytic Redox-Neutral Alkoxyacylation of Alkenes
作者:Fu-Tong Cen、Yu Sun、Jian-Ping Qu、Yan-Biao Kang
DOI:10.1021/acs.orglett.3c03583
日期:2023.12.22
blocks in organic synthesis. By utilizing CBZ6, with an oxidative potential of −2.16 V (vs the saturated calomel electrode), as a redox-neutral photocatalyst, alkoxyacylation of olefins was accomplished under the irradiation of visible light via a cationic intermediate. It involves the addition of an acyl radical to olefin to form a radical intermediate and the following oxidation of the radical intermediate
In the presence of a catalytic amount of mesoporous aluminosilicate (Al-MCM-41), both allyltrimethylsilane and silyl enol ether reacted with various acetals under mild reaction conditions to afford the corresponding homoallyl ethers and beta-alkoxy ketones, respectively. The catalyst was easily recovered from the reaction mixture and could be reused in the same reaction without a significant loss of catalytic activity. Moreover, Al-MCM-41 exhibited high chemoselectivity for acetal over aldehyde in the reactions. (C) 2010 Elsevier Ltd. All rights reserved.