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

• DOI: 10.5012/bkcs.2005.26.9.1359
• Publication Date: 2010-06-21T03:09:07Z
• Authors: Thanh Thien Co
• Keywords: Tsuji–Trost reaction; Coordination sphere

A series of new chiral [iminophosphoranyl]ferrocenes, {<TEX>${\eta}^5-C_5H_4-(PPh_2=N-2,6-R_2-C_6H_3)$</TEX>}Fe{<TEX>${\eta}^5-C_5H_3-1-PPh^2-2-CH(Me)NMe_2$</TEX>} (1: R = Me, <TEX>$^iPr$</TEX>), {<TEX>${\eta}^5{-C_5H_4-(PPh_2=N-2,6-R_2}^1-C_6H_3)$</TEX>}Fe{<TEX>${\eta}^5-C_5H_3-1-(PPh_2=N-2,6-R_2-C_6H_3)-2-CH(Me)R_2$</TEX>} (2: <TEX>$R^1\;=\;Me,\;^iPr;\;R^2\;=\;NMe_2$</TEX>, OMe), and <TEX>$({\eta}^5-C_5H_5)Fe$</TEX>{<TEX>${\eta}^5-C_5H_4-1-PR_2-2-CH(Me)N=PPh_3$</TEX>} (3:R Ph, <TEX>$C_6H_{11}$</TEX>) have been prepared from the reaction [1,1'-diphenylphosphino-2-(N,N-dimethylamino) ethyl]ferrocene with arylazides (1 & 2) phosphine dichlorides (<TEX>$R_3PCl_{2}$</TEX>) [1,1'-diphenylphosphino-2-aminoethyl]ferrocene (3), respectively. They form palladium complexes type <TEX>$[Pd(C_3H_5)(L)]BF_4$</TEX> (4-6: L 1-3), where ligand (L) adopts an <TEX>${\eta}^2-N,N\;(2)\;or\;{\eta}^2$</TEX>-P,N (3) as expected. In case 1, a potential terdentate, <TEX>${\eta}^2$</TEX>-P,N mode is realized exclusion –=NAr group coordination sphere. Complexes 4-6 were employed catalysts for allylic alkylation 1,3-diphenylallyl acetate leading to almost stoichiometric product yield modest enantiomeric excess (up 74% ee). Rh(I)-complexes incorporating 1-3 also in situ cinnamyl probe both regio- enantioselectivities reaction. The exhibited high regiocontrol favor linear achiral isomer regardless employed.