of alkyl and acyl radicals onto electron-poor olefins or diisopropyl azodicarboxylate has been carried out on a multi-gram scale under continuous flow conditions. The process is based on the use of the inorganic photocatalyst tetrabutylammonium decatungstate (TBADT), which is capable to activate selectively a variety of CH bonds in different substrates, including aldehydes, amides, ethers and alkanes
已经在连续流动条件下以克为单位进行了一组烷基和酰基自由基在贫电子烯烃或偶氮二羧酸二异丙酯上的原子经济自由基共轭加成反应。该方法基于使用无机光催化剂四丁基癸二酸铵(TBADT),它能够选择性地活化不同底物(包括醛,酰胺,醚和烷烃)中的多种CH键。根据该程序已经合成了广泛的合成靶,包括1,4-双官能化的衍生物(例如1,4-二酮或酮酯)。所有反应均在中观条件下进行规模的流量光反应器,包括缠绕在水冷500 W中压汞蒸气灯周围的紫外线透明FEP管(氟化乙烯丙烯)的盘管。这种光化学设备的使用导致了停留时间的减少,相对于相应的批处理过程所测得的停留时间而言,STY(时空产率)和生产率值显着提高,通常会导致整体效率的提高。过程的可持续性(过程质量强度– PMI –值低至10 kg kg -1)。
Solar light-driven photocatalyzed alkylations. Chemistry on the window ledge
Tetrabutylammonium decatungstate photocatalysis is effective for the C–H activation of alkanes, aldehydes, ethers and amides and the alkylation of alkenes occurs effectively by merely exposing the solution to the sun in a glass vessel on a window ledge (up to 10 g per dm2 in a few days).
Photoamidation of electron-poor olefins has been achieved by means of a radical-induced CH functionalization in amides. Tetrabutylammonium decatungstate was used as photocatalyst of the reaction and allowed the smooth generation of different carbon-centered radicals depending on the amide structure.