Organic amine mediated cleavage of Caromatic-Cα bonds in lignin and its platform molecules

The activation and cleavage of C-C bonds remains a critical scientific issue in many organic reactions and is an unmet challenge due to their intrinsic inertness and ubiquity. Meanwhile, it is crucial for the valorization of lignin into high-value chemicals. Here, we proposed a novel strategy to enhance the C-aromatic-C-alpha bond cleavage by pre-functionalization with amine sources, in which an active amine intermediate is first formed through Markovnikov hydroamination to reduce the dissociation energy of the C-aromatic-C-alpha bond which is then cleaved to form target chemicals. More importantly, this strategy provides a method to achieve the maximum utilization of the aromatic nucleus and side chains in lignin or its platform molecules. Phenols and N,N-dimethylethylamine compounds with high yields were produced from herbaceous lignin or the p-coumaric acid monomer in the presence of industrially available dimethylamine (DMA).

Automated summary

This study proposed a novel strategy to enhance the cleavage of C-aromatic-C-alpha bonds by pre-functionalization, allowing the valorization of lignin into high-value chemicals.