Chiral [Iminophosphoranyl]ferrocenes: Synthesis, Coordination Chemistry, and Catalytic Application

Bulletin of the Korean chemical society

Sang Chul Shim¹  Tae-Jeong Kim¹  Thanh Thien Co¹  Chan Sik Cho¹  Dong-Uk Kim¹ 

关键词: Chiral ferrocenes;    Iminophosphoranes;    N ligand;    Palladium catalysts;    Allylic alkylation;   

DOI  :  

学科分类：化学（综合）

来源: Korean Chemical Society

【 摘 要 】

A series of new chiral [iminophosphoranyl]ferrocenes, {�?⁵-C₅H₄-(PPh₂=N-2,6-R₂-C₆H₃)}Fe{�?⁵-C₅H₃-1-PPh2-2-CH(Me)NMe₂} (1: R = Me, ⁱPr), {�?⁵-C₅H₄-(PPh₂=N-2,6-R₂¹-C₆H₃)}Fe{�?⁵-C₅H₃-1-(PPh₂=N-2,6-R₂-C₆H₃)-2-CH(Me)R²} (2: R¹ = Me, Pr; R² = NMe₂, OMe), and (�?⁵-C₅H₅)Fe{�?⁵-C₅H₄-1-PR₂-2-CH(Me)N=PPh₃} (3:R = Ph, C₆H₁₁) have been prepared from the reaction of [1,1`-diphenylphosphino-2-(N,N-dimethylamino) ethyl]ferrocene with arylazides (1 & 2) and the reaction of phosphine dichlorides (R<sub>3</sub>PCl<sub>2</sub>) with [1,1`- diphenylphosphino-2-aminoethyl]ferrocene (3), respectively. They form palladium complexes of the type [Pd(C₃H₅)(L)]BF₄ (4-6: L = 1-3), where the ligand (L) adopts an �?²-N,N (2) or �?²-P,N (3) as expected. In the case of 1, a potential terdentate, an �?²-P,N mode is realized with the exclusion of the ?P=NAr group from the coordination sphere. Complexes 4-6 were employed as catalysts for allylic alkylation of 1,3-diphenylallyl acetate leading to an almost stoichiometric product yield with modest enantiomeric excess (up to 74% ee). Rh(I)-complexes incorporating 1-3 were also prepared in situ for allylic alkylation of cinnamyl acetate as a probe for both regio- and enantioselectivities of the reaction. The reaction exhibited high regiocontrol in favor of a linear achiral isomer regardless of the ligand employed.

【 授权许可】

Unknown