Synthesis of the First Chiral Bidendate Bis(trifluoromethyl)phosphane Ligand through Stabilization of the Bis(trifluoromethyl)phosphanide Anion in the Presence of Acetone
作者:Berthold Hoge、Christoph Thösen、Ingo Pantenburg
DOI:10.1002/chem.200600259
日期:2006.12.4
tetracarbonyl-molybdenum complex. The stabilization of the P(CF3)2- ion in the presence of acetone is based on the formation of a dynamic Lewis acid/Lewis base couple, (CF3)2PC(CH3)2O-. Although there is no spectroscopic evidence for the formation of the formulated alcoholate ion, the intermediate formation of (CF3)2PC(CH3)2O- could be proved through the reaction with (CF3)2PP(CF3)2, which yields the novel
P(CF3)2-离子和丙酮的路易斯酸/路易斯碱加合物形成导致负超共轭减少,因此限制了CF键的活化。在丙酮存在下,P(CF3)2-离子产生的热稳定性提高,可以进行选择性取代,并可以合成手性双齿双(三氟甲基)膦配体的第一个实例:DIOP衍生物,[(2, 2-二甲基-1,3-二氧戊环-4,5-二基)双(亚甲基)双(二苯基膦),其中磷原子上的苯基被强吸电子的三氟甲基取代。合成的二齿(CF3)2P配体的高电子受体强度通过相应的四羰基-钼配合物的结构和振动研究证明。在丙酮存在下P(CF3)2-离子的稳定是基于动态路易斯酸/路易斯碱对(CF3)2PC(CH3)2O-的形成。尽管没有光谱证据表明所形成的醇盐离子,但可以通过与(CF3)2PP(CF3)2反应来证明(CF3)2PC(CH3)2O-的中间形成,从而生成新的膦-次膦酸酯配体(CF3)2PC(CH3)2OP(CF3)2。用固体PtCl2处理后,该配