杂化MCM-41固载催化剂的合成、表征及催化研究

Synthesis,Characterization and Catalytic Applications of Asymmetric Hydrogenation Catalyst Immobilized on Hybrid MCM-41

用γ-氯丙基三乙氧基硅烷和正硅酸乙酯混合在模板剂引导下共水解合成了有机-无机杂化的介孔分子筛MCM-41,通过与(1R,2R)-1,2-环己二胺和RuCl2(p-cymene)2反应,制成了固载化的不对称氢转移反应催化剂,并进行了FT-IR、XRD和N2吸附-脱附的表征.不对称氢转移催化反应结果表明,在催化还原苯乙酮成α-苯乙醇的反应中,平均转化率为6.42%,产物平均ee(对映体过量)值为12.64%,固载化催化剂与其匀相体系的催化性能相比(转化率为3.56%,ee值为33.04%),转化率更高,ee值有一定程度的降低.

Organic inorganic hybrid mesoporous molecular sieve MCM 41 was synthesized by co condensation of tetraethoxysilane (TEOS) and 3 chlorpropyl triethoxysilane,then reacted with (1R,2R) 1,2 diaminocyclohexane and dichloro(p cymene) ruthenium dimer successively to afford immobilized asymmetric hydrogen transfer catalyst.The prepared catalyst was characterized by means of FT IR,PXRD and N2 adsorption desorption isotherms,and was applied in asymmetric hydrogen transfer reactions of reduction of acetophenone to α phenyl ethanol.It showed an average conversion of 6.42%and ee (enantiomeric excess) value of 12.64%in all 3 performances.The conversion was a little higher than its corresponding homogenous counterpart (conversion of 3.56%and ee value of 33.04%),while the ee values were somewhat lower.