Better Performance of Monodentate
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‐Stereogenic Phosphanes Compared to Bidentate Analogues in Pd‐Catalyzed Asymmetric Allylic Alkylations
作者:Arnald Grabulosa、Guillermo Muller、Rosa Ceder、Miguel Ángel Maestro
DOI:10.1002/ejic.201000308
日期:2010.7
-1,3-Ph 2 -C 3 H 3 )P] (6a, 6d) were obtained. Palladium allyl complexes were screened as precatalysts in the allylic substitution of rac-3-acetoxy-1,3-diphenyl-1-propene (I) and (E)-3-acetoxy-1-phenyl-1-propene (III) with dimethyl malonate as the nucleophile. The various catalytic precursors showed a wide range of activity and selectivity. The bismonodentate phosphane complexes 3 are more active than
[Pd(η 3 -2-Me-C 3 H 4 )P 2 ]PF 6 阳离子烯丙基钯配合物 3a-3f, 4a, 4e, 5e 使用一组单齿 P-立体异构膦合成,P=PPhRR '(af)和二膦(PhRPCH 2 ) 2 (1a, 1e)或PhRPCH 2 Si(Me) 2 CH 2 PPhR (2e)。具有双取代烯丙基 (η 3 -1,3-Ph 2 C 3 H 3 ) 和单齿膦的类似阳离子络合物未作为稳定固体分离;仅获得[PdCl(η 3 -1,3-Ph 2 -C 3 H 3 )P] (6a, 6d)。钯烯丙基配合物被筛选为 rac-3-acetoxy-1,3-diphenyl-1-propene (I) 和 (E)-3-acetoxy-1-phenyl-1-propene (III) 的烯丙基取代的预催化剂丙二酸二甲酯作为亲核试剂。各种催化前体显示出广泛的活性和选择性。双齿磷烷配合物 3