Stereoelectronic Factors in Iron Catalysis: Synthesis and Characterization of Aryl-Substituted Iron(II) Carbonyl P–N–N–P Complexes and Their Use in the Asymmetric Transfer Hydrogenation of Ketones
作者:Peter E. Sues、Alan J. Lough、Robert H. Morris
DOI:10.1021/om2005172
日期:2011.8.22
(2a–c), in a one-pot template reaction, the corresponding (S,S)-trans-[Fe(CH3CN)2(PR2-CH2CH═NCH(Ph)CH(Ph)N═CHCH2-PR2)][BPh4]2 complexes (3a–c) were generated and then converted to precatalysts 1a–c via CO addition reactions. While investigating compounds 1a–c, an alternative route for synthesizing phosphonium dimers was developed that allowed the facile introduction of tetrafluoroborate counterions
一系列五个(S,S)-反-[Fe(CO)(Br)(PR 2 -CH 2 CH = NCH(Ph)CH(Ph)N = CHCH 2 -PR 2)] [X]化合物(合成了1a – c,X = BPh 4;1d,e,X = BF 4)并测试了苯乙酮的不对称转移氢化(ATH)。三种配合物具有甲基取代的芳基(a,R =对-CH 3 C 6 H 4;b,R =邻-CH 3 C 6高4 ; c,R = 3,5-(CH 3)2 C 6 H 3),两个具有三氟甲基取代的芳基(d,R =对-CF 3 C 6 H 4;e,R = 3,5-( CF 3)2 C 6 H 3)。使用已知和新的phospho二聚体,[环-(PR 2 CH 2 CH(OH)-)2 ] [Br] 2(2a – c),在一锅模板反应中,相应的(S,S)-反-[Fe(CH 3 CN)2(PR 2 -CH 2 CH = NCH(Ph)CH(Ph)N