无水甲基磺酸铝合成、表征及其催化四氢吡喃化反应性能

Synthesis, Characterization and Catalytic Activity in the Tetrahydropyranylation of Anhydrous Auminum Mthansulfonates

摘要:

通过水热合成法合成了水合甲基磺酸铝([Al(H2O)6][CH3SO3]3)，将其在265℃焙烧5 h得到无水甲基磺酸铝(Al2(OH)(CH3SO3)5)。 通过元素分析和红外光谱分析确定了二者的结构组成。热重分析和固体核磁 27Al MAS NMR分析表明水合甲基磺酸铝在热分解过程中发生部分水解，形成了与两个铝原子桥连的羟基。在室温下，以二氯甲烷为溶剂，Al2(OH)(MS)5可高效催化正丁醇的四氢吡喃化反应，产率和选择性均可达到100%。同时，与[Al(H2O)6][CH3SO3]3及其他无机铝盐催化剂相比，Al2(OH)(MS)5的催化活性最高，可重复多次使用。

Abstract:

Hexaaquaaluminum methanesulfonate crystals, [Al(H2O)6][CH3SO3]3 were synthesized by hydrothermal reaction of Al(OH)3 with methansulfonic acid. Heating at 265 ℃ for 5 h, (Al2(OH)(CH3SO3)5) was gotten. The six-coordinated enviroment of the central Al atom is also determined by Elemental Analysis, Chemical titration and 27Al MAS NMR measurement. Thermogravimetric and Fourier transform infrared analysis show that the decomposition intermediate product at 265-365 癈 is Al2(OH)(CH3SO3)5 and the final product is amorphous Al2O3 residue with about 0.8 wt% SO3. Tetrahydropyranylation of n-butanol at room temperature in dichloromethane, catalyzed by Al2(OH)(CH3SO3)5 got 100% yielding. After compared, Al2(OH)(MS)5 exhibits the highest catalytic activity (100% yield) among various aluminum salts. Furthermore, Al2(OH)(CH3SO3)5 can be recycled, which enable to be environmentally benign and economical candidates for similar catalytic reactions.