Department of Chemistry, Faculty of Science, Hokkaido University, Sapporo 060-0810, Japan.
J Am Chem Soc. 2013 Feb 27;135(8):2947-50. doi: 10.1021/ja3126239. Epub 2013 Feb 15.
The site-selective activation and borylation of unactivated C(sp(3))-H bonds in 2-alkylpyridines to form primary and secondary alkylboronates was achieved using silica-supported monophosphine-Ir catalysts. This borylation occurs selectively at C-H bonds located γ to the pyridine nitrogen atom. The site-selectivity of this reaction suggests that the C-H bond cleavage occurs with the assistance of a proximity effect due to N-to-Ir coordination.
使用负载在二氧化硅上的单膦-铱催化剂,实现了在 2-烷基吡啶中未活化的 C(sp(3))-H 键的位点选择性活化和硼化,生成伯烷基和仲烷基硼酸酯。这种硼化反应选择性地发生在吡啶氮原子γ位的 C-H 键上。该反应的位点选择性表明,由于 N 到 Ir 的配位,C-H 键的断裂是在近程效应的协助下发生的。