Ishida Kento, Tobita Fumiya, Kusama Hiroyuki
Department of Chemistry, Faculty of Science, Gakushuin University, 1-5-1 Mejiro, Toshima-ku, Tokyo, 171-8588, Japan.
Chemistry. 2018 Jan 12;24(3):543-546. doi: 10.1002/chem.201704776. Epub 2017 Nov 30.
Intermolecular carbon-carbon bond-forming reaction between readily available acylsilanes and aldehydes was achieved under photoirradiation conditions with assistance of a catalytic amount of Lewis acid. Nucleophilic addition of photochemically generated siloxycarbenes to aldehydes followed by 1,4-silyl migration afforded synthetically useful α-siloxyketones. Electrophilic activation of aldehydes by Lewis acid is highly important to realize this reaction efficiently, otherwise the yield of the desired coupling products were significantly decreased. Noteworthy is that a formal cross benzoin-type reaction using acylsilanes was achieved under Lewis acidic conditions. This is the first example of Lewis acid-catalyzed reaction of photochemically generated siloxycarbenes with electrophiles.
在催化量的路易斯酸的辅助下，在光照射条件下实现了易得的酰基硅烷与醛之间的分子间碳-碳键形成反应。光化学产生的甲硅烷氧基卡宾对醛进行亲核加成，随后进行1,4-硅基迁移，得到了具有合成价值的α-甲硅烷氧基酮。路易斯酸对醛的亲电活化对于有效实现该反应非常重要，否则所需偶联产物的产率会显著降低。值得注意的是，在路易斯酸性条件下实现了使用酰基硅烷的形式上的交叉安息香型反应。这是光化学产生的甲硅烷氧基卡宾与亲电试剂的路易斯酸催化反应的首个实例。
