Jaouadi Khaoula, Abdellaoui Mehdi, Levernier Etienne, Payard Pierre-Adrien, Derat Etienne, Le Saux Thomas, Ollivier Cyril, Torelli Stéphane, Jullien Ludovic, Plasson Raphaël, Fensterbank Louis, Grimaud Laurence
LBM, Département de chimie, École Normale Supérieure, PSL University, Sorbonne Université, CNRS, 75005, Paris, France.
Sorbonne Université, CNRS, Institut Parisien de Chimie Moléculaire, 75005, Paris, France.
Chemistry. 2023 Oct 23;29(59):e202301780. doi: 10.1002/chem.202301780. Epub 2023 Sep 18.
Metallaphotoredox catalyzed cross-coupling of an arylbromide (Ar-Br) with an alkyl bis(catecholato)silicate (R-Si ) has been analyzed in depth using a continuum of analytical techniques (EPR, fluorine NMR, electrochemistry, photophysics) and modeling (micro-kinetics and DFT calculations). These studies converged on the impact of four control parameters consisting in the initial concentrations of the iridium photocatalyst ([Ir] ), nickel precatalyst ([Ni] ) and silicate ([R-Si ] ) as well as light intensity I for an efficient reaction between Ar-Br and R-Si . More precisely, two regimes were found to be possibly at play. The first one relies on an equimolar consumption of Ar-Br with R-Si smoothly leading to Ar-R, with no side-product from R-Si and a second one in which R-Si is simultaneously coupled to Ar-Br and degraded to R-H. This integrative approach could serve as a case study for the investigation of other metallaphotoredox catalysis manifolds of synthetic significance.
利用一系列分析技术（电子顺磁共振、氟核磁共振、电化学、光物理）和建模方法（微观动力学和密度泛函理论计算），对金属光氧化还原催化的芳基溴（Ar-Br）与烷基双（儿茶酚）硅酸盐（R-Si）的交叉偶联反应进行了深入分析。这些研究聚焦于四个控制参数的影响，这四个参数包括铱光催化剂的初始浓度（[Ir]）、镍预催化剂的初始浓度（[Ni]）、硅酸盐的初始浓度（[R-Si]）以及光强I，它们对Ar-Br与R-Si之间的高效反应具有重要作用。更确切地说，发现可能存在两种反应机制。第一种机制依赖于Ar-Br与R-Si等摩尔消耗，顺利生成Ar-R，且R-Si没有副产物；第二种机制是R-Si同时与Ar-Br偶联并降解为R-H。这种综合方法可作为研究其他具有合成意义的金属光氧化还原催化体系的案例研究。
