Catalytic O–H bond insertion reactions using surface modified sewage sludge as a catalyst†
Developing a greener, sustainable catalyst is a very important but challenging task in organic synthesis. Herein, for the first time, we choose more economical and greener surface modified sewage sludge-derived carbonaceous materials (SW) treated by perchloric acid as a new catalyst for carbene insertion of α-aryl α-diazoacetates into O–H bonds of phenols with good yields and high functional group tolerance. Significantly, we explored the scope of natural phenols with compelling biological activity, and successfully afforded the O–H insertion and meta C–H functionalization products. Their structures have been confirmed by single-crystal X-ray crystallography. Furthermore, the bioactivities (anti-tumor and anti-inflammatory) of the majority of O–H insertion products are better than those of the natural phenols themselves. The IC50 values indicated that the remarkable compounds 7a (IC50 = 16.80 μM) and 7c (IC50 = 16.48 μM) had better inhibition for tumor cell A-549 than positive control DDP (IC50 = 20.62 μM). It should be noted that these transformations may provide a new strategy to derive natural products and discover new drugs.