Ring‐Closing Metathesis of Aliphatic Ethers and Esterification of Terpene Alcohols Catalyzed by Functionalized Biochar

Abstract Functionalized biochars, renewable carbon materials prepared from waste biomass, can catalyze transformations of a range of oxygen‐containing substrates via hydrogen‐bonding interactions. Good conversions (up to 75.2 %) to different O‐heterocycles are obtained from ring‐closing C−O/C−O metathesis reactions of different aliphatic ethers under optimized conditions using this heterogeneous, metal‐free, and easy separable catalyst. The diversity in the sorts of O‐containing feedstocks is further demonstrated by the utilization of functionalized biochar to promote the esterification of terpene alcohols, an important reaction in food and flavor industries. Under the optimized conditions, full conversions to various terpene esters are obtained. Moreover, both of the reactions studied herein are performed under neat conditions, thus increasing the overall sustainability of the process described.