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。
Combining Transition Metal Catalysis with Radical Chemistry: Dramatic Acceleration of Palladium-Catalyzed CH Arylation with Diaryliodonium Salts
作者:Sharon R. Neufeldt、Melanie S. Sanford
DOI:10.1002/adsc.201200738
日期:2012.12.14
This paper describes a photoredox palladium/iridium-catalyzed C-H arylation with diaryliodonium reagents. Details of the reaction optimization, substrate scope, and mechanism are presented along with a comparison to a related method in which aryldiazonium salts are used in place of diaryliodonium reagents. The unprecedentedly mild reaction conditions (25 masculineC in methanol), the requirement for
C(sp2)–H bond oxidation of oximes or azobenzenes with diverse carboxylic acids has been developed. In contrast to the previous catalytic systems, this protocol features mild conditions (close to room temperature for most cases) and a broad substrate scope (up to 64 examples), thus constituting a versatile method to directly prepare diverse O-aryl esters. Moreover, the superiority of the nitrate additive
Pd-catalyzed decarboxylative ortho-acylation of O-methyl oximes with phenylglyoxylic acids
作者:Zhiyong Yang、Xiang Chen、Jidan Liu、Qingwen Gui、Kai Xie、Miaomiao Li、Ze Tan
DOI:10.1039/c2cc38861h
日期:——
Aryl ketones were synthesized via Pd-catalyzed decarboxylative coupling between O-methyl oximes and phenylglyoxylic acids using (NH4)2S2O8 as the oxidant.
A mild and efficient Cp*IrIII‐catalyzed (Cp* = pentamethylcyclopentadienyl) ortho‐C(sp2)–Hamidation of O‐methyl ketoximes with sulfonamides is developed and furnishes the corresponding products in good yields.
开发了一种温和有效的Cp * Ir III催化(Cp * =五甲基环戊二烯基)的O-甲基酮肟与磺酰胺酰胺化邻-C(sp 2)-H酰胺,并提供了高收率的相应产品。