Racemo-Selective Synthesis of <i>a</i><i>nsa</i>-Zirconocene Derivates from Zirconium Biphenolate Complexes
作者:Hans-Robert H. Damrau、Eva Royo、Stephan Obert、Frank Schaper、Armin Weeber、Hans-Herbert Brintzinger
DOI:10.1021/om010605j
日期:2001.12.1
rac-3c, respectively. More highly substituted indenyl ligands, on the other hand, give initially kinetically controlled mixtures of the rac- and meso-zirconocene BIP derivatives 4c, 5c, and 6c, from which the pure rac-derivatives are obtained as thermodynamically favored products by heating the reaction mixtures to 75 °C for 5−7 h. The meso-to-rac isomerization of 6c is catalyzed by addition of TEMPO and
通式(BIP)ZrCl 2(THF)2(1a - c)的双酚锆锆配合物的立体选择反应,其中BIP = 3,3'- iPr 2 -6,6'-Me 2 -1,1'-联-2-酚盐(a),3,3'- tBu 2 -5,5'-Me 2 -1,1'-联-2-酚盐(b)或3,3',5,5'- t卜4 -1,1'-二-2-酚(Ç)中,用1个当量各种的锂或镁盐的柄型-双(茚基)配位体得到柄-zirconocenes外消旋-C 2 H ^ 4(茚基)2锆(BIP)(图2b),外消旋-Me 2的Si(茚基)2锆(BIP)(图3c),外消旋-Me 2的Si(2-ME-IND)2锆(BIP)(图4c),外消旋-我2 Si(2-Me-4-Ph-Ind)2 Zr(BIP)(5c)和rac-Me 2 Si(2-Me-Benz [ e ] Ind)2 Zr(BIP)(6c)的分离产率为60-75%。C 2 H 4(Ind)2