Hydrogen acceptor, 1-octene

Secondary alcohols are converted into ketones in 70-98% isolated yields when refluxed with Raney nickel in benzene for 1-24 h with azeotropic removal of water [927]. The addition of 1-octene as a hydrogen acceptor does not affect the yields. Primary alcohols, under such reaction conditions, usually suffer decarbonylation and yield hydrocarbons vith one less carbon [927] (equation 240). 

A fast isomerization of the kinetic product 1-octene to internal octenes has been observed. The stoichiometric alkane dehydrogenation mediated by 17 is not inhibited by the presence of N2 and a-olefins, and the rate of the reaction seems to be accelerated by the presence of water. Complex 17 can be regenerated from 19 by reacting with O2 and HO Ac [92]. This suggests that a catalytic cycle involving O2 as hydrogen acceptor is plausible. However, preliminary attempts to make this reaction catalytic have been thwarted by catalytic instability towards O2 at the temperature required for alkane dehydrogenation. 

---