Abstract
While numerous organo(metallic)catalyst systems were documented for dearomative hydroboration of N-aromatics, alkoxide base catalysts have not been disclosed thus far. Described herein is the first example of alkoxide-catalyzed hydroboration of N-heteroaromatics including pyridines, providing a broad range of reduced N-heterocycles with high efficiency and selectivity. Mechanistic studies revealed an unprecedented counterintuitive dearomatization pathway, in which 1) pyridine-BH 3 adducts undergo a hydride attack by alkoxyborohydrides, 2) in situ generated BH 3 serves as a catalytic promoter, and 3) 1,4-dihydropyridyl borohydride is in a predominant resting state.
Original language | English |
---|---|
Pages (from-to) | 6320-6325 |
Number of pages | 6 |
Journal | Chemistry - A European Journal |
Volume | 25 |
Issue number | 25 |
DOIs | |
State | Published - 2 May 2019 |
Externally published | Yes |
Keywords
- N-heteroarenes
- alkali base catalyst
- dearomatization
- hydroboration
- ionic mechanism