prior formation of N-activated pyridines, organometallic reagents, and extra oxidation operation for the construction of a C–C bond at the C4-position of the pyridines in previous methods are not required. The corresponding mechanism and the key roles of the organoborane were elaborated by the combination of H/D scrambling experiments, 11B NMR studies, intermediate trapping experiments and computational
第一NaBEt 3 H-催化分子间吡啶Chichibabin型烷基化和其与烯烃作为潜亲核试剂衍生物呈现BET的协助3,以及一系列支链C4烷基化吡啶,即使高度拥塞全碳季中心含-三芳基甲烷可以以区域特异性方式获得。因此,传统上依赖于高成本和低可用性的过渡金属催化剂,先形成N活化的吡啶,有机金属试剂和在以前方法中不需要额外的氧化操作来在吡啶的C4位上构建C–C键。H / D加扰实验,11 B NMR研究,中间捕获实验和计算研究相结合详细阐述了有机硼烷的相应机理和关键作用。这种直接的,机械上独特的有机催化技术不仅为经典的但仍未得到很好开发的奇奇巴宾型反应打开一扇新门,而且为开发新型C–C键形成方法建立了新平台。
Nickel-catalysed para-CH activation of pyridine with switchable regioselective hydroheteroarylation of allylarenes
作者:Wei-Chih Lee、Chien-Hung Chen、Cheng-Yuan Liu、Ming-Shiuan Yu、Yung-Huei Lin、Tiow-Gan Ong
DOI:10.1039/c5cc07455j
日期:——
para-CH activation of pyridine with allylbenzene is described by Ni/Al cooperative catalysis to achieve branch and linear selectivity.
使用Ni/Al协同催化描述了烯丙基苯与吡啶的para-CH活化,以实现支链和线性选择性。
Electrochemically Driven C4-Selective Decyanoalkylation of Cyanopyridines with Unactivated Alkyl Bromides Enabling C(sp<sup>3</sup>)–C(sp<sup>2</sup>) Coupling
C4-selective decyanoalkylation has been established to access diverse 4-alkylpyridines in one step. The reaction proceeds through the single electron reduction/radical–radical coupling tandem process under mild electrolytic conditions, achieving the cleavage of the C(sp2)–CN bond and the formation of C(sp3)–C(sp2). The practicality of this protocol is illustrated by no sacrificial anodes, a broad substrate
Photoinduced Radical Desulfurative C(sp<sup>3</sup>)–C(sp<sup>2</sup>) Coupling via Electron Donor–Acceptor Complexes
作者:Jiaxuan Shen、Jincan Li、Meijun Chen、Xuerong Yue、Xin Shi
DOI:10.1021/acs.orglett.4c00162
日期:2024.2.23
Herein, we disclose a radical desulfurative C–C coupling protocol for the synthesis of 4-alkylpyridines. A variety of substituents on both benzyl thiols and 4-cyanopyridines are tolerated. The reaction is carried out under mild and photocatalyst- and transition-metal-free conditions. Preliminary mechanistic studies show that an electron donor–acceptor complex is formed between benzyl thiols and 4-cyanopyridines