Recent Advances in Functionalization of α‐C(sp³)–H Centres in Inactivated Ethers through Cross Dehydrogenative Coupling

Abstract

Carbon–carbon and carbon–heteroatom bond construction through oxidative carbon–hydrogen bond activation has attracted much attention in synthetic organic chemistry. Recently, a variety of reactions of inactivated cyclic ethers (THF, THP and dioxane) and acyclic ethers with various coupling partners have been reported. Despite the absence of phenyl rings and high oxidation potentials, these ethers worked efficiently under oxidative conditions. This review focusses on recent reports of C–C and C–heteroatom bond formation in these cyclic and acyclic ethers through cross dehydrogenative coupling.

Combustion-Synthesized Porous CuO-CeO2-SiO2 Composites as Solid Catalysts for the Alkenylation of C(sp3)-H Bonds Adjacent to a Heteroatom via Cross-Dehydrogenative Coupling

“…The major product could be achieved in the presence of either Ce or Cucontaining materials, confirming that both Ce and Cu species are responsible for the selective cross-dehydrogenative coupling between 1,1-diphenylethylene and THF (Table 3). According to the previous studies, a plausible redox cycle for the direct alkenylation of THF with 1,1-diphenylethylene catalyzed by the Cu 1 Ce 0.7 Si catalyst was proposed (Figure 13) [12,13,15,78,83,84]. First, decomposition of DTBP into tert-butoxy radicals is accelerated at high temperatures in the presence of transition metal species [12,77,79,84].…”

“…The CDC for the α-functionalization of ethers and amines is still a grand challenge because of the inert and ubiquitous nature of the C(sp 3 )-H bond. Many efforts to expand this convenient method have been reported in the past decade, in which first-row transition metals, namely copper, iron, cobalt, are the most used catalysts [6,[9][10][11][12]. Liu and co-workers investigated the α-functionalization of ethers with olefins in the presence of CuI catalyst to obtain α-alkenylated ethers [13].…”

Recent Developments in Transition Metal‐Free Cross‐Dehydrogenative Coupling Reactions for C–C Bond Formation

“…Peroxides are strong oxidants and are widely used in dehydrogenative reactions. [ 21 ] A few metal‐free and peroxide‐assisted coupling reactions (organic and inorganic) yet reported, have been demonstrated in this section.…”

Recent Advances in Visible-Light-Induced Cross Dehydrogenation Coupling Reaction under Transition Metal-Free Conditions

“…1.1 C(sp 3 )-C(sp 3 )偶联 2011 年, Tan 课题组 [34] 报道了可见光诱导叔胺的 α- 同年, König 等 [35] 以 Eosin Y 染料作光敏剂, 研究了 可 见 光 诱 导 下 N-芳 基 四 氢 异 喹 啉 和 亲 核 试 剂 的 C(sp 3 )-H/C(sp 3 )-H 偶联反应(Eqs. 3,4). 与前者相比, 该体系具有催化剂用量低, 反应时间短等优点.…”