Reaction Pathways and Redox States in α-Selective Cobalt-Catalyzed Hydroborations of Alkynes |
| |
| Authors: | Clemens K Blasius Dr Vladislav Vasilenko Regina Matveeva Prof Hubert Wadepohl Prof Lutz H Gade |
| |
| Institution: | Anorganisch-Chemisches Institut, Universität Heidelberg, Im Neuenheimer Feld 270, 69120 Heidelberg, Germany |
| |
| Abstract: | Cobalt(II) alkyl complexes supported by a monoanionic NNN pincer ligand are pre-catalysts for the regioselective hydroboration of terminal alkynes, yielding the Markovnikov products with α:β-(E) ratios of up to 97:3. A cobalt(II) hydride and a cobalt(II) vinyl complex appear to determine the main reaction pathway. In a background reaction the highly reactive hydrido species specifically converts to a coordinatively unsaturated cobalt(I) complex which was found to re-enter the main catalytic cycle. |
| |
| Keywords: | alkenyl boronates alkynes cobalt pincer ligand T-shaped complex |
|
