@article {11093,
	title = {Inactivity of iridium{\textendash}triphenylphosphine complexes for catalytic imine hydrogenation: formation of neutral, dihydrido-ortho-metallated species},
	journal = {Reaction Kinetics and Catalysis Letters},
	volume = {98},
	year = {2009},
	month = {12/2009},
	pages = {193 - 204},
	abstract = {Reactions of cis,trans,cis-[Ir(H)2(PPh3)2(MeOH)2]PF6 in MeOH with the imines Ph(R{\textquoteright})C=NR under 1 atm H2 precipitate the neutral, Ir(III)-dihydrido complexes [Ir(H)2{RN=C(R{\textquoteright})(o-C 6H4)}(PPh3)2], where R = alkyl or benzyl, and R{\textquoteright} = Ph, H, or Me; the dihydrides are well characterized through elemental analysis, NMR and IR data and, in one case, with the imine Ph2C=NCH2Ph, an X-ray structure. These products are formed via intermediate ortho-metallated species, exemplified by [Ir(H){PhCH2N=CPh(o-C 6H4)}(PPh3)2(MeOH)]PF6 in the case of the Ph2C=NCH2Ph reaction; the intermediate then reacts with H2 (via net heterolytic cleavage: H2 {\textrightarrow} H- + H+) to give the neutral dihydride and HPF6 as co-product. The {\textquoteleft}unique{\textquoteright} imine PhCH=NPh, under the same conditions, does not form a dihydride and instead is readily catalytically hydrogenated to PhCH2N(H)Ph; remarkably, we have shown previously that this imine is {\textquoteleft}unique{\textquoteright} within the corresponding Rh system in that no catalytic hydrogenation occurs because the amine product {\textquoteleft}poisons{\textquoteright} the Rh centre by coordination through the N-phenyl ring.},
	issn = {1588-2837},
	doi = {10.1007/s11144-009-0095-0},
	author = {Marcazzan, Paolo and James, Brian R.}
}
