The Mechanism of a Ligand-Promoted C(sp3)-H Activation and Arylation Reaction via Palladium Catalysis: Theoretical Demonstration of a Pd(II)/Pd(IV) Redox Manifold
The Mechanism of a Ligand-Promoted C(sp3)-H Activation and Arylation Reaction via Palladium Catalysis: Theoretical Demonstration of a Pd(II)/Pd(IV) Redox Manifold
复制标题
钯催化配体促进的 C(sp3)–H 活化和芳基化反应的机制：Pd(II)/Pd(IV) 氧化还原流形的理论论证
DOI：
10.1021/ja512374g
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发表时间：
2015-02-11
影响因子：
15
通讯作者：
Wang, Xiaotai
中科院分区：
文献类型：
--
作者：
Dang, Yanfeng;Qu, Shuanglin;Wang, Xiaotai
Density functional theory (DFT) computations (BP86 and M06-L) have been utilized to elucidate the detailed mechanism of a palladium-catalyzed reaction involving pyridine-type nitrogen-donor ligands that significantly expands the scope of C(sp(3))-H activation and arylation. The reaction begins with precatalyst initiation, followed by substrate binding to the Pd(II) center through an amidate auxiliary, which directs the ensuing bicarbonate-assisted C(sp(3))-H bond activation producing five-membered-ring cyclopalladate(II) intermediates. These Pd(II) complexes further undergo oxidative addition with iodobenzene to form Pd(IV) complexes, which proceed by reductive C-C elimination/coupling to give final products of arylation. The base-assisted C(sp(3))-H bond cleavage is found to be the rate-determining step, which involves hydrogen bond interactions. The mechanism unravels the intimate involvement of the added 2-picoline ligand in every phase of the reaction, explains the isolation of the cyclopalladate intermediates, agrees with the observed kinetic hydrogen isotope effect, and demonstrates the Pd(II)/Pd(IV) redox manifold.
