バイオマスの有効利用を指向した光と金属触媒を用いる炭素－炭素結合切断反応の開発

建立了一种新的光/铜接力系统，用于具有β - o -4和β -1键的木质素模型化合物的有氧氧化破碎。与热铜催化的好氧降解相比，木质素模型化合物具有更高的反应效率和不同的产物分布。在本研究中，我们使用具有β - o -4系的简单化合物作为模型底物，因为它代表了木质素中存在的最丰富的重复单元，并且研究其对光和铜催化剂的行为将为我们了解类似条件下天然木质素的解聚过程提供帮助。将1,2-二氯乙烷中的模型底物用蓝色led灯照射在空气中，在ms - acr + BF4-(2.0 mol %)、乙酸铜（20 mol %）和乙酸钠（2.0 mol %）的存在下，底物在12 h后被消耗。得到3,4-二甲氧基苯甲醛和2-甲氧基苯甲酸酯的分离收率分别为66%和56%。因此，β - o -4谱系中的碳-碳键被劈裂。接下来，我们将好氧裂解条件应用于另一个木质素模型化合物家族，该家族具有β -1连锁，这是木质素中发现的第二丰富的重复单元。实验证明它也是一种可行的底物。因此，我们的光催化体系也可以应用于具有β -1键的木质素模型化合物。

A new light/copper relayed system is developed for aerobic oxidative fragmentation of lignin model compounds having beta-O-4 and beta-1 linkage. Lignin model compounds are successfully broken down with an enhanced reaction efficiency and different product distribution in comparison to thermal copper-catalyzed aerobic degradation.In this study, we used the simple compound having a beta-O-4 linage as the model substrate because it represents the most abundant repeating unit existing in lignin and the investigation on its behavior toward light and a copper catalyst would provide us with an insight into a depolymerization process of native lignin under similar conditions. When the model substrate in 1,2-dichloroethane was irradiated with a blue LEDs lamp under air in the presence of Mes-Acr+ BF4-(2.0 mol %),copper(II) acetate (20 mol %), and sodium acetate (2.0 equiv), the substrate was consumed after 12 h. 3,4-Dimethoxybenzaldehyde and 2-methoxyphenyl formate were obtained in 66% isolated yield and 56% GC yield, respectively. Thus, carbon-carbon bonds contained in the beta-O-4 linage is cleaved. Next, the conditions for aerobic fragmentation were applied to another family of lignin model compound having a beta-1 linkage, which is the second most abundant repeating unit found in lignin. It was proved to be also viable substrate. Thus, our photo-catalyzed system could also be applied for lignin model compounds having a beta-1 linkage.