Enantioselective Michael Addition Reaction Catalysed by Enantiopure Binuclear Nickel(II) Close‐Ended Helicates
作者:Eswaran Chinnaraja、Rajendran Arunachalam、Krishanu Samanta、Ramalingam Natarajan、Palani S. Subramanian
DOI:10.1002/adsc.201901350
日期:2020.3.4
The enantiopure Ni(II) helicates [Ni2L1RR.Cl2] (1), [Ni2L1SS.Cl2] (1′), [Ni2L2RR.Cl2] (2), [Ni2L2SS.Cl2] (2′) were synthesized by one‐pot self‐assembly technique from R‐(+)‐ or S‐(−)‐1,1′‐binaphthyl‐2,2′‐diamine, with 4‐methyl‐2,6‐diformyl phenol or 4‐tert‐butyl‐2,6‐diformyl phenol and nickel salts. This binuclear double stranded Ni(II) helicates were characterized by ESI‐MS, IR and single crystal
的对映体纯的Ni(II)helicates [倪2大号1 RR .CL 2 ](1),[倪2大号1 SS .CL 2 ](1' ),[倪2大号2 RR .CL 2 ](2), [Ni 2 L 2 SS .Cl 2 ](2')是通过一锅自组装技术由R -(+)-或S -(-)-1,1'-联萘-2,2'-合成的二胺,与4-甲基-2,6-二甲酰基苯酚或4-叔丁基-2,6-丁基-二甲酰基苯酚和镍盐。这种双核双链Ni(II)螺旋结构在适用的情况下通过ESI-MS,IR和单晶X射线结构表征。大量的手性研究表明,该络合物在本质上是对映纯的。从配体L 1 RR和L 2 RR到Ni(II)金属中心的手性转移产生了ΔΔ几何手性,而它们的对映体对应物L 1 SS和L 2 SS 这些对映体纯的螺旋产物被用作催化剂,将1,3-二羰基化合物与β-硝基苯乙烯不对称迈克尔加成,以高产率(96-98%)和ee(78-94%)生产硝基烷。