Formation of an air-stable diborane via a stepwise BH3 addition of pyrido[1,2-a]isoindole with H2 evolution.
Jiaqi DongLutao ZhangDehui TanJianfeng WuNan WangSoren K MellerupSuning WangDeng-Tao YangPublished in: Chemical communications (Cambridge, England) (2021)
A novel and air-stable organo(hydro)diborane featuring a five-membered aryl ring supported bridging B-C-B three-centre-two-electron (3c-2e) bond has been reported. Pyrido[1,2-a]isoindole was found to undergo a stepwise BH3 addition reaction, during which a mono-BH3 adduct was formed from a electrophilic addition at the Cγ in pyrido[1,2-a]isoindole. A molecule of hydrogen was eliminated throughout the second step of addition reaction. DFT calculations indicate that the H2 evolution is concerted to the second BH3 addition rather than forming BC before the second BH3 attack.