Dehydrogenation of alkanes catalyzed by an iridium phosphinito PCP pincer complex

The novel phosphinito iridium PCP pincer complex, IrH4{C6H3-2,6-(OPPr2')(2)} can be conveniently synthesized and isolated in 74% overall yield. The complex catalyzes the dehydrogenation of linear alkanes to alkenes at the rate of 13 turnovers min(-1) at 200 degreesC. This catalytic activity is slightly higher than that exhibited by iridium complexes of analogous bis(phosphino) PCP ligands. The bis(phosphinito) complex is resistant to decomposition for periods up to 7 days at temperatures as high as 200 degreesC thus matching the thermal stability of the bis(phosphino) pincer complexes. (C) 2004 Elsevier B.V. All rights reserved.