A novel visible-light-induced radical cascade bromocyclization of N-arylacrylamides has been accomplished. This reaction overcomes the overbromination at the benzene rings suffered in traditional electrophilic reactions, thus enabling the first highly chemoselective synthesis of valuable 3-bromomethyloxindoles. The combination of pyridine and anhydrous medium is identified as the key factor for the
一种新型的可见光诱导的N-芳基
丙烯酰胺自由基级联
溴环化反应已经完成。该反应克服了传统亲电反应中苯环上的过度
溴化,从而首次实现了有价值的3-
溴甲基羟
吲哚的高度
化学选择性合成。
吡啶和无
水介质的组合被认为是当前光反应体系中高
化学选择性的关键因素,其可能通过抑制N-
溴代琥珀
酰亚胺原位生成低浓度Br 2来发挥作用。此外,温和的反应条件确保生成各种具有优异官能团耐受性的新所需产物。