Boron-Assisted Cobalt-Catalyzed C–H Methylation Using CO<sub>2</sub> and H<sub>2</sub>
作者:Qin Shi、Haiyan Hu、Minxing Du、Yajun Sun、Yudong Li、Yuehui Li
DOI:10.1021/acs.orglett.3c02406
日期:2023.10.6
and pyrroles in the presence of cobalt/B(C6F5)3 cocatalysts. The Lewis acidic additive B(C6F5)3 is essential to achieving good reactivity for a broad scope of substituted indoles and pyrroles (20 examples, up to 92% yields). The C–H methylation is accomplished via the CO2 reduction/C–C bond formation/reduction sequence. Water is the only byproduct. This system based on the use of non-noble metal catalysts
杂芳烃(例如吲哚、吡咯等)的C-H甲基化经常应用于药物/生物相关化合物的合成。我们在此报告了使用CO 2 /H 2作为甲基化试剂,在钴/B(C 6 F 5 ) 3助催化剂存在下选择性地进行吲哚和吡咯的C-H甲基化。路易斯酸性添加剂 B(C 6 F 5 ) 3对于实现广泛的取代吲哚和吡咯的良好反应性至关重要(20 个实例,产率高达 92%)。 C–H 甲基化是通过 CO 2还原/C–C 键形成/还原序列完成的。水是唯一的副产品。该系统基于使用非贵金属催化剂,是 C-H 甲基化的环境友好型替代方案。
Reactivity of tetrahydrochromeno[2,3-b]indoles: chromic indicators of cyanide
作者:Nicholas Douglas、Charles J. Neef、Robert A. Rogers、Jake A. Stanley、Jacob Armitage、Ben Martin、Todd W. Hudnall、William J. Brittain
DOI:10.1002/poc.3158
日期:2013.8
The synthesis and reactivity of a tetrahydrochromeno[2,3‐b]indoles are reported. Evidence for reversible ring‐opening is based on H/D exchange and trapping experiments. These compounds readily undergo reaction with tetra‐n‐butylammonium cyanide. The cyanide reaction is 10–100× faster when the solution is irradiated with 350 nm light. Reaction with trimethylsilyl cyanide occurs only with UV irradiation