Synthesis of Pincer Hydrido Ruthenium Olefin Complexes for Catalytic Alkane Dehydrogenation

Abstract

A series of new hydrido Ru­(II) olefin complexes supported by isopropyl-substituted pincer ligands have been synthesized and characterized. These complexes are thermally robust and active for catalytic transfer and acceptorless alkane dehydrogenation. Notably, the alkane dehydrogenation catalysts are tolerant of a number of polar functional species.

Challenges and opportunities for alkane functionalisation using molecular catalysts

“…Although less efficient, pincer Ru catalysts are more tolerant of polar functional groups than the related pincer Ir catalysts. 75 , 77 A lipophilic t Bu 2 dpb-ligated hydrido Pt complex 16 shows low activity for the TD of cycloalkanes with TBE. 78 …”

Synthesis of Symmetric and Nonsymmetric NiII Thiophosphinito PECSP (E = S, O) Pincer Complexes and Their Applications in Kumada Coupling under Mild Conditions

“…Apart from these Ir complexes, only a handful of other R POCSP R transition metal complexes are known (Figure ). Huang et al presented a study of acceptorless COA dehydrogenation using a series of R POCSP R Ru catalysts and the group of Morales‐Morales reported on a Ph POCSP Ph Pd chlorido complex that was tested for Suzuki–Miyaura cross‐coupling reaction of bromobenzene and phenylboronic acid. Also in this case the asymmetric complex was found to be a better, faster catalyst than the symmetric Ph POCOP Ph analogue under identical reaction conditions …”

“Pincer” Pyridine–Dicarbene–Iridium and ‐Ruthenium Complexes and Derivatives Thereof

“…For comparison, the nbd bond length in trans,cis ‐[RuCl 2 (nbd)(py) 2 ] is 1.390 Å and, surprisingly, in [Ru(PCP)(nbd)Cl] {PCP = 1,3‐bis (diisopropylphosphinomethyl)‐phenylene}, is ca. 1.411 Å, implying again better back‐bonding from the metal fragment to the norbornadiene in the latter.…”