Photochemical Monoalkylation of Propanedinitrile by Electron-Rich Alkenes

The synthesis of monoalkylated propanedinitriles was achieved upon photoirradiation of MeCN/H2O solutions containing propanedinitrile (1; malononitrile) and electron-rich alkenes in the presence of lithium carbonate and a catalytic amount of 9-cyanophenanthrene or redox-type photosensitizers (electron-mediating photosensitizers), through regioselective anti-Markovnikov photochemical polar addition of 1 into electron-rich alkenes. With 2,5-dimethyl-2,4-hexadiene (2g) as an electron-rich alkene, propanedinitrile-incorporated dimer 4g was obtained.

单烷基化丙二腈类化合物的合成可通过如下路径实现：将丙二腈（propanedinitrile，又称malononitrile，编号为1）与富电子烯烃溶解于乙腈/水（MeCN/H₂O）混合溶剂中，在碳酸锂及催化量的9-氰基菲或氧化还原型光敏剂（电子介导型光敏剂）存在下进行光辐照，使丙二腈对富电子烯烃发生区域选择性反马氏（anti-Markovnikov）光化学极性加成。当以2,5-二甲基-2,4-己二烯（2g）作为富电子烯烃底物时，可得到引入丙二腈单元的二聚体4g。