低温条件下氯化铌催化果糖有效转化制5-羟甲基糠醛

Efficient synthesis of 5-hydroxymethylfurfural from fructose at low temperature with niobium chloride catalyst

以金属氯化物为催化剂研究了果糖在低温条件下转化制5-羟甲基糠醛(5-HMF),筛选出适合的催化剂,考察了催化剂用量、果糖加入量、共催化剂、共溶剂、反应温度与反应时间等因素的影响,探究了可能的反应机理。结果表明,以30mg果糖为原料,NbCl_(5)为催化剂,用量为果糖摩尔量的15%,500μL二甲基亚砜为溶剂,在50℃下反应240min,果糖转化率和5-HMF收率分别可达97%和75%。NbCl_(5)可能通过BrФnsted酸与Lewis酸协同作用催化反应,其主要与果糖端位的羟基和羰基部分作用。该反应体系也适用于菊糖在低温条件下转化制5-HMF。

A series of metal chlorides were used as the catalysts for the conversion of fructose into 5-hydroxymethylfurfural(5-HMF)at low temperature.Preferred catalyst was screened out for the conversion of fructose.The effects of catalyst loading,fructose dosage,co-catalyst,co-solvent,reaction temperature and time were investigated in detail.The possible mechanism was studied as well.The results indicated that a fructose conversion of 97%and a 5-HMF yield of 75%could be achieved when 30mg of fructose was added into 500μL of dimethyl sulfoxide with NbCl_(5)(15(mol)%of fructose)catalyst at 50℃for 240min.NbCl_(5)may work as the catalyst by the synergistic action of both BrФnsted and Lewis acids.NbCl_(5)could primarily interact with the end hydroxyl and carbonyl groups of fructose.The reaction system was also suitable for the conversion of inulin into 5-HMF at low temperature.