1,2-Hydroboration of Pyridines by Organomagnesium
Xinli Liu1, Bingwen Li2, Xiufang Hua1,3
1State Key Laboratory of Polymer Physics and Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022, China.
Abstract:
Hydroboration of pyridine derivatives at room temperature with earth-abundant and biocompatible magnesium catalysts ligated by phosphinimino amides is developed. Fine turnover frequency (TOF) and distinguished 1,2-regioselectivity have been achieved. The exclusive chemoselective carbonyl hydroboration happens with competitive TOF. A HBpin assisted mechanism is deduced by the reaction rate law, activation parameters, and kinetic isotope effect (KIE) in combination with DFT calculations. To our knowledge, this is the first example of pyridine 1,2-dearomatization by Mg-based catalysts.
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