Rational Design of Highly Active “Hybrid” Phosphine–Phosphinite Pincer Iridium Catalysts for Alkane Metathesis
作者:Agnieszka J. Nawara-Hultzsch、Jason D. Hackenberg、Benudhar Punji、Carolyn Supplee、Thomas J. Emge、Brad C. Bailey、Richard R. Schrock、Maurice Brookhart、Alan S. Goldman
DOI:10.1021/cs400624c
日期:2013.11.1
phosphine–phosphinite pincer ligands (PCOP) and the corresponding iridium complexes were synthesized (3c–e). In tandem with olefin-metathesis catalyst MoF12, (tBu4PCOP)IrH2 displays significantly higher activity for the metathesis of n-hexane than does (tBu4PCP)IrH2 or (tBu4POCOP)IrH2. (tBu2PCOPiPr2)IrH4 (3d) is even more active (>30-fold more active than (tBu4POCOP)IrH2) and affords nearly 4.6 M alkane products
无论是双膦和bisphosphinite钳形络合物(吨BU4 PCP)IRH 2和(吨BU4 POCOP)IRH 2可以cocatalyze烷烃与烯烃复分解催化剂的串联复分解,但两种复合物催化过程中具有不同的静止状态,这表明不同的步骤是营业额-在每种情况下都进行限制。这导致了一个假设,即具有中间性质的复合物比这两个物种中的任何一个都具有更高的催化活性。相应地,合成了“杂化”膦-次膦酸盐钳形配体(PCOP)和相应的铱配合物(3c – e)。与烯烃复分解催化剂MoF12串联,吨BU4 PCOP)IRH 2个为复分解显示显著更高的活性Ñ正己烷比确实(吨BU4 PCP)IRH 2或(吨BU4 POCOP)IRH 2。(吨BU2 PCOP我PR2)IRH 4( 3D)是更有效(> 30倍更有效(吨BU4 POCOP)IRH 2)和,得到近4.6米烷烃产物后,在125℃8小时下进行。