Aerobic Oxidation of Pd<sup>II</sup> to Pd<sup>IV</sup> by Active Radical Reactants: Direct C–H Nitration and Acylation of Arenes via Oxygenation Process with Molecular Oxygen
oxidative C–H nitration and acylation of arenes with simple and readily available tert-butyl nitrite (TBN) and toluene as the radical precursors has been developed. Molecular oxygen is employed as the terminal oxidant and oxygen source to initiate the active radical reactants. Many different directing groups such as pyridine, pyrimidine, pyrazole, pyridol, pyridylketone, oxime, and azo groups can be employed
已经开发了钯催化的好氧氧化C–H硝化和芳烃与简单易用的亚硝酸叔丁酯(TBN)和甲苯作为自由基前体的酰化反应。分子氧被用作末端氧化剂和氧源以引发活性自由基反应物。在这些新颖的转化中可以使用许多不同的导向基团,例如吡啶,嘧啶,吡唑,吡啶醇,吡啶基酮,肟和偶氮基团。通过自由基过程的Pd II / Pd IV催化循环是这些氧化的CH–H硝化和酰化反应的最可能途径。
Palladium-Catalyzed Oxidative Direct<i>ortho</i>-C-H Acylation of Arenes with Aldehydes under Aqueous Conditions
作者:Fuhong Xiao、Shuqing Chen、Huawen Huang、Guo-Jun Deng
DOI:10.1002/ejoc.201501187
日期:2015.12
Palladium-catalyzed ortho-acylation of arenes with aldehydes in the presence of tert-butyl hydroperoxide (TBHP) as the oxidant under aqueous conditions has been demonstrated. The acylation reaction exhibits excellent regioselectivity and wide functional group tolerance.
Four Tandem C–H Activations: A Sequential C–C and C–O Bond Making via a Pd-Catalyzed Cross Dehydrogenative Coupling (CDC) Approach
作者:Srimanta Guin、Saroj Kumar Rout、Arghya Banerjee、Shyamapada Nandi、Bhisma K. Patel
DOI:10.1021/ol302438z
日期:2012.10.19
the ortho C–H bond with respect to a directing group has been accomplished via a Pd(II)-catalyzed cross dehydrogenative coupling approach using alkylbenzene as the synthetic equivalent of an aroyl moiety. The reaction proceeds through sequential C–C and C–O bond making at the expense of four consecutive C–H bondcleavages (three sp3 benzylic C–H’s and one sp2 arene C–H) to selectively install an aroyl
Molecular oxygen, the most environmentally friendly oxidant, was used as the terminal oxidant for palladium-catalyzed radical oxidative acylation of arenes.