The Reductive Amination of Biomass-Based Aldehydes and Alcohols towards 2,5-bis(aminomethyl)furan: Progress, Challenges and Prospects

Primary diamines play an important role in the chemical industry, where they are widely used as raw materials for the manufacture of pharmaceuticals and polymers. Currently, primary diamines are mainly derived from petroleum, while harsh or toxic conditions are often needed. Biomass is abundant and renewable , which serves as a promising alternative raw material to produce primary diamines. This review primarily focuses on the synthesis of 2,5-bis(aminomethyl)furan (BAMF), a bio-based diamine with potential as a biomonomer for polyamides and polyureas. Specifically, this review emphasizes the synthesis of BAMF from three biomass-derived alcohols and aldehydes, namely 5-hydroxymethylfurfural (HMF), 2,5-bis(hydroxymethyl)furan (BHMF), and 2,5-diformylfuran (DFF). These are the key substrates to get BAMF and could be readily obtained from carbohydrates. Even though great effort has been put into the synthesis of BAMF, it remains a tough problem to obtain BAMF with a high yield at a low cost due to the inevitable side reactions, such as unwanted hydrogenation reactions and condensation reactions. Many strategies have been proposed to solve this problem, such as the hydrogen-borrowing strategy and stepwise reductive amination strategy. Herein, we will summarize the key advancements in this area, and discuss the challenges that need to be responded in the future, hoping to provide an insight into the design and development of a more efficient system for the production of biomass-derived diamines.