B<sub>2</sub>pin<sub>2</sub>-Mediated Cascade Cyclization/Aromatization Reaction: Facial Access to Functionalized Indolizines.
Xiaoning LiZunsheng ChenWeiming ChenXin XieHui ZhouYingmei LiaoFu-Chao YuJiuzhong HuangPublished in: Organic letters (2022)
Herein, a B<sub>2</sub>pin<sub>2</sub>-mediated radical cascade cyclization/aromatization reaction of enaminone with pyridine is described. This strategy provides a practical way for the construction of valuable functionalized indolizines under metal-, external oxidant-, and base-free conditions, which could be compatible with various kinds of functional groups, such as halogen, π-system, heterocycle, ferrocenyl, etc. A preliminary mechanism investigation indicated that the pyridine-boryl radical formed in situ triggered the reaction to occur.