Toward Stereoselective Lactide Polymerization Catalysts: Cationic Zinc Complexes Supported by a Chiral Phosphinimine Scaffold
作者:Hongsui Sun、Jamie S. Ritch、Paul G. Hayes
DOI:10.1021/ic201139b
日期:2011.9.5
toward alkane elimination reactions with diethylzinc and ethyl-[methyl-(S)-lactate]zinc to give the heteroleptic complexes [(dbf)MePhP═NAr}ZnR][B(C6F5)4] (Ar = Dipp, 13: R = Et; 15: R = methyl-(S)-lactate; Ar = Mes, 14: R = Et; 16: R = methyl-(S)-lactate). By contrast, reaction of the tetraphenylborate derivative 11 with diethylzinc yielded a phenyl transfer product, [(dbf)MePhP═NDipp]ZnPh2 (17). Complex
的P -stereogenic膦亚胺配体(DBF)MePhP═NAr(7:Ar为卜先生; 8:Ar为的Mes; DBF =二苯并呋喃,迪普= 2,6-二异丙基,MES = 2,4,6-三甲基苯基)的合成如通过母体膦(rac)-(dbf)MePhP(6)与有机叠氮化物的反应生成消旋体。用布朗斯台德酸使配体7和8质子化,得到氨基bo硼酸盐[(7)-H] [BAr 4 ](9:Ar = C 6 F 5;11:Ar = Ph)和[(8)-H ] [BAr 4 ](10:Ar = C 6 F 5;12:Ar = Ph)。质子化的配体9和10对与二乙基锌和乙基[[-((S)-乳酸)锌]锌的烷烃消除反应具有活性,从而得到杂配物[(dbf)MePhP═NAr} ZnR] [B(C 6 F 5))4 ](Ar = Dipp,13:R = Et;15:R =甲基-(S)-乳酸酯; Ar = Mes,14:R