Synthesis of (POCOP)Co(Ph)(X) Pincer Complexes and Observation of Aryl–Aryl Reductive Elimination Involving the Pincer Aryl
作者:Bryan J. Foley、Chandra Mouli Palit、Samuel D. Timpa、Oleg V. Ozerov
DOI:10.1021/acs.organomet.8b00511
日期:2018.11.12
elimination reaction that involves the POCOP ligand. Metalation of the parent (POCOP)H ligand with CoCl2 and DMAP led to the formation of (POCOP)CoCl (A-1). Metathesis of A-1 with Me3SiX reagents allowed isolation of (POCOP)CoBr (A-2), (POCOP)CoI (A-3), and (POCOP)CoOTf (A-4). Reactions of A-1 with NaOtBu, MeLi, and PhLi led to (POCOP)CoOtBu (A-5), (POCOP)CoMe (A-6), and (POCOP)CoPh (A-7). Treatment of A-1
制备了一系列由POCOP钳形配体支撑的正方形平面,低自旋Co(II)和Co(III)配合物,目的是探索潜在参与芳基卤化物偶联催化的反应(POCOP = 2,6-二异丙基次膦氧基苯基)。研究表明,可以设想到催化循环的Co(III)-芳基中间体,但是所需的催化作用因涉及POCOP配体的CC还原消除反应而脱轨。母体(POCOP)H配体与CoCl 2和DMAP的金属化导致(POCOP)CoCl(A-1)的形成。的复分解A-1与我3的(POCOP)COBR(SIX试剂允许隔离A-2 ),(POCOP)的Col(A-3)和(POCOP)CoOTf(A-4)。的反应A-1用的NaO吨卜,将MeLi和PhLi导致(POCOP)COO吨BU(A-5 ),(POCOP)到来(A-6 ),和(POCOP)COPH(A-7 )。用PhSH处理A-1令人惊讶地导致(POCOP)CoSPh(A-8),而无需添加碱。A