Dehydrogenation of n-Alkanes Catalyzed by Iridium “Pincer” Complexes:  Regioselective Formation of α-Olefins

Cyclometalation Using d-Block Transition Metals: Fundamental Aspects and Recent Trends

“…413,414 For synthetic purposes most appealing, complexes 258-260 and derivatives are highly efficient catalysts for the homogeneous dehydrogenation of unfunctionalized alkanes. 415 The initial selectivity for terminal olefins is high, 416 and turnover numbers as high as 3300 mol alkane per mol catalyst have been achieved. 419 As a competitive reaction, C-H bond activation in one of the phosphine-bound phenyl groups takes place, thus forming a fourmembered iridacycle.…”

Structural and dynamic properties of propane coordinated to TpRh(CNR) from a confrontation between theory and experiment

“…In the past decade, useful processes have been developed that employ alkane activation via oxidative addition; significant examples include alkane dehydrogenation (1)(2)(3)(4), alkane and arene borylation (5)(6)(7)(8)(9), and alkane metathesis (10). In all of these developments, selectivity in activation has been a critical issue, and rhodium and iridium transition metal complexes have been found to show a strong preference for the activation of the methyl C-H bonds in alkanes, despite the presence of weaker methylene C-H bonds.…”

Organometallic C—H Bond Activation: An Introduction

“…Although the lPr pcP complex appeared to afford greater regioselectivity than the ffiu PCP complex, it was found that both complexes in fact gave very high kinetic selectivity for α-olefins (135). Due to more rapid isomerization relative to dehydrogenation, however, the build-up of α-olefin tended to be lower with the tBu PCP complex although this was found to be highly dependent on reaction conditions.…”

“…reflux The lPr PCP derivative gave rates and TONs that were still higher (134); more importantly, this complex was found to catalyze the selective dehydrogenation of w-alkanes to give α-olefins (135).…”