diastereomeric resonances in their NMR spectra. Product ratios from alkylation by acetoacetate were thermodynamic, while those from alkylation by the enamine were presumed to be kinetic. The excess of one diastereomer over the other, relating in principle to an “optical yield” at the new chiral carbon center induced by the existing metal chirality, ranged from 10 to 64% depending on the nucleophile and the electrophile
手性亲电体烷基化CpFe的量(CO)(L)CH 2 Cl和CpFe的量(CO)(L)(CH 2 CH 2)+ SO 3 CF 3 -(L = PPH 3和三(ö
联苯基)
亚磷酸酯)由前手性亲核试剂
乙酰乙酸叔丁酯钠和
吡咯烷
环己酮烯胺产生了八种可能的烷基
铁产物中的六种。L是o的两个产品
亚磷酸二
联苯酯和
乙酰乙酸叔丁酯没有形成亲核试剂,大概是因为空间位阻过大。在每种情况下形成的两种非对映异构体的相对量可从其NMR光谱中的非对映异构体共振轻松确定。通过
乙酰乙酸烷基化得到的产物比率是热力学的,而通过烯胺的烷基化得到的产物比率被认为是动力学的。一种非对映异构体相对于另一种非对映异构体的过量,原则上与现有
金属手性引起的在新手性碳中心的“光学收率”有关,介于10%到64%之间,具体取决于亲核试剂和亲电试剂,但最明显的是,
配体L.