Solvent promoted reversible cyclometalation in a tethered NHC iridium complex.
نویسندگان
چکیده
Reaction of [Ir(COD)(py-I(t)Bu)](+) (py-I(t)Bu = 3-tert-butyl-1-picolylimidazol-2-ylidene) with acetonitrile results in reversible intramolecular C-H bond activation of the NHC ligand and formation of [Ir(η(2):η(1)-C8H13)(py-I(t)Bu')(NCMe)](+). Coordinated COD acts as an internal hydride acceptor and acetonitrile coordination offsets the otherwise unfavourable thermodynamics of the process.
منابع مشابه
Hydrogen shuttling: synthesis and reactivity of a 14-electron iridium complex featuring a bis(alkyl) tethered N-heterocyclic carbene ligand.
Solvent dependent double C-H activation in an Ir(NHC)(2) system generates an agostically stabilized 14-electron complex featuring a face-capping bis(alkyl) tethered NHC ligand [NHC = N-heterocyclic carbene]. These activation processes are reversible, and the resulting ligand-derived hydrogen shuttle can be applied to the dehydrogenation of BN-containing substrates.
متن کاملRoom temperature and solvent-free iridium-catalyzed selective alkylation of anilines with alcohols.
A bidentate iridium NHC-phosphine complex has been developed and applied to the N-monoalkylation of aromatic amines with a wide range of primary alcohols and to the N-heterocyclization of amino alcohols. This reaction resulted in high isolated product yields, even at room temperature and under solvent-free conditions.
متن کاملPractically convenient and industrially-aligned methods for iridium-catalysed hydrogen isotope exchange processes.
The use of alternative solvents in the iridium-catalysed hydrogen isotope exchange reaction with developing phosphine/NHC Ir(I) complexes has identified reaction media which are more widely applicable and industrially acceptable than the commonly employed chlorinated solvent, dichloromethane. Deuterium incorporation into a variety of substrates has proceeded to deliver high levels of labelling ...
متن کاملApplication of the π-accepting ability parameter of N-heterocyclic carbene ligands in iridium complexes for signal amplification by reversible exchange (SABRE).
The new π-accepting ability parameter (PAAP) appears to be the best tool to analyse the electronic properties of NHC ligands in [Ir(H)2(NHC)(Py)3](+) complexes for SABRE. Together with the buried volume, the efficiency of hyperpolarisation transfer in SABRE, depending on the exchange rate of pyridine, can be described.
متن کاملOn the involvement of NHC carbenes in catalytic reactions by iridium complexes, nanoparticle and bulk metal dispersed in imidazolium ionic liquids.
D/H exchange reactions at C2, C4 and C5 of the imidazolium cation were observed in catalytic hydrogenation reactions promoted by classical Ir(I) colloid precursors and [Ir(0)](n) nanoparticles dispersed in deuterated imidazolium ionic liquids indicating the participation of carbene species in this media. However, no D/H exchange reaction was observed in cyclohexene hydrogenation promoted by iri...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید
ثبت ناماگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید
ورودعنوان ژورنال:
- Chemical communications
دوره 50 6 شماره
صفحات -
تاریخ انتشار 2014