Catalytic asymmetric carbomagnesiation of unactivated alkenes. A new, effective, active, cheap and recoverable chiral zirconocene
作者:Louise Bell、Richard J Whitby、Raymond V.H Jones、Michael C.H Standen
DOI:10.1016/0040-4039(96)01561-4
日期:1996.9
terminal alkenes catalysed by (R,R)-ethylene-1,2-bis(η5-4,5,6,7-tetrahydro-1-indenyl)zirconium(R)-1,1′-binaphth-2,2′-diolate gave low turnovers and enantioexcesses. A novel Ci symmetric zirconocene dichloride CpCp′ZrCl2 (Cp = C5H5, Cp′ = 1-neomenthyl-4,5,6,7-tetrahydroindenyl) was prepared which gave better enantioselectivity, is cheaper to make, catalytically more active, and recoverable.
通过催化末端烯烃的ethylmagnesiation([R ,- [R )-亚乙基-1,2-双(η 5 -4,5,6,7-四氢-1-茚基)合锆([R)-1,1'- binaphth- 2,2'-羟乙酸盐产生较低的营业额和对映体过量。制备了一种新的C i对称的二茂锆锆CpCp'ZrCl 2(Cp = C 5 H 5,Cp'= 1-新薄荷基-4,5,6,7-四氢茚基),该对映体具有更好的对映选择性,制造成本更低,催化作用更多。活跃且可恢复。