Remote amide-directed palladium-catalyzed benzylic C–H amination with N-fluorobenzenesulfonimide

Abstract

An unprecedented remote amide-directed palladium-catalyzed intermolecular highly selective benzylic C-H amination with N-fluorobenzenesulfonimide is developed, which represents the first direct benzylic C-H amination with a non-nitrene nitrogen source. This methodology provides a novel approach to circumvent the common ortho aromatic C-H selectivity in directed palladium catalyzed C-H functionalization.

Amide as Nitrogen Source： Amination and Mechanism

“…在酰胺为氮源构建 C-N 键的转化中, Bogdal [4] 报道 了微波促进下的卤代芳烃与酰胺/内酰胺的反应, 实现 了酰胺/内酰胺的烷基化; Sharpless 等 [5] 报道了酰胺与烯 烃的不对称氨羟基化反应, 在烯烃上引入酰胺基团; Zhang 等 [6] 报道了钯催化下在苯甲基上引入苯磺酰胺基 团; Zeni 等 [7] 报道了铜催化下酰胺基团取代硒酚 2 位的 碘形成 2-酰胺硒酚的反应. 酰胺作为氮源, 除了可以在 分子中引入酰胺基外, 也可以直接在分子中引入胺基, 如卤代芳烃与酰胺在钯催化下可以形成芳香胺 [8] .…”

2.8 C—N Bond Formation by Arene C—H Activation Using a Palladium Catalyst

“…Moreover, 4-methyl derivatives undergo efficient benzylic C-H amination in the presence of palladium(II) acetate and N-fluorobenzenesulfonimide. [42] Primary allylic positions also react under these conditions. [43] Taken together, these results raise the issue of chemoselectivity of the ortho C-H amination with more complex substrates.…”

Metal-Catalyzed and Metal-Free Intermolecular Amination of Light Alkanes and Benzenes

“…Noteworthy are original contributions by Zhang 82 on the use of NFSI for the amide-directed, palladium-catalyzed C–H amination of N -phenylacetamides selectively at the ortho, para, or benzylic (for N-p -tolylacetamides) position. The benzylic amination was further elaborated by Zhang and Liu 83 with copper-mediated systems that remarkably favor primary over secondary benzylic sites.…”