含多羟基的手性Salen Mn(Ⅲ)配合物的合成与催化性质

Synthesis and Catalysis of Chiral Salen Mn(Ⅲ) Complexes Containing Multihydroxyl Substituents

合成并表征了2个含有多羟基官能团的新型手性Salen((R,R)-N,N′-[2,2′-双(次氨基次甲基)]双[4-(亚甲基-N,N′-二乙醇氨基)-6-(1,1-二叔丁基)苯酚]-1,2-环己二胺)(5)和(R,R)-N,N′-[2,2′-双(次氨基次甲基)]双[4-(亚甲基-N,N′-二乙醇氨基)-6-(1,1-二叔丁基)苯酚]-1,2-二苯基乙二胺)(6))的Mn(Ⅲ)配合物7和8。以吡啶氮氧化物(PyNO)为助催化剂,NaClO为氧化剂,在水和二氯甲烷双相反应体系中,研究了配合物7和8对非官能团烯烃环氧化的不对称催化行为。结果表明,2个配合物对以苯乙烯和茚为底物的不对称环氧化反应均具有较好的催化效果,分别得到32.3%～52.9%和72.8%～89.7%的ee值;催化剂用量为基于烯烃的量10mol%的情况下,反应可在0.5h以内完成。研究发现在[BMIM]PF6([BMIM]+=1-丁基-3-甲基咪唑阳离子)离子液存在的条件下,催化剂8可以重复使用4次,且ee值没有明显的下降。

Two chiral Salen（（R,R）-N,N＇-[2,2＇-his （nitrilomethylidyne）] bis [4-（methylene-N,N＇-diethanolamino）-6- （1,1-dinethylethyl）phenoloto]-1,2-cyclohexanediamine and （（R,R）-N,N＇-[2,2＇-bis（nitrilomethylidyne）lbis[4-（methyl- ene-N,N＇-diethanol amino）-6-（1,1-dinethylethyl）phenoloto]-1,2-diphenyldiamine） Mn （Ⅲ） complexes 7 and 8 containing multihydroxyl groups were synthesized and employed in the asymmetric epoxidation of unfunctionalized alkene with NaCIO as oxidant in the presence of pyridine N-oxide （PyNO） as co-catalysts in CH2Cl2/H2O. The epoxidations of styrene give enantioselectivities from 32.3% to 52.9% and the epoxidations of indene give ee from 72.8% and 89.7%; When 10mol% catalyst based on the olefins was used, the reaction can be completed within half an hour. Catalyst 8 could be effectively recycled for 3 times without a significant decrease of selectivity in the presence of ionic liquid [BMIM]PF6 （[BMIM]^＋= 1-butyl-3-methylimidazolium）.