Asymmetric hydrogenation of quinazolinium salts catalysed by halide-bridged dinuclear iridium complexes bearing chiral diphosphine ligands.
نویسندگان
چکیده
Asymmetric hydrogenation of quinazolinium salts was catalysed by halogen-bridged dinuclear iridium complexes bearing chiral diphosphine ligands, yielding tetrahydroquinazoline and 3,4-dihydroquinazoline with high enantioselectivity. A derivative of chiral dihydroquinazoline was used as a chiral NHC ligand.
منابع مشابه
Additive effects of amines on asymmetric hydrogenation of quinoxalines catalyzed by chiral iridium complexes.
The additive effects of amines were realized in the asymmetric hydrogenation of 2-phenylquinoxaline, and its derivatives, catalyzed by chiral cationic dinuclear triply halide-bridged iridium complexes [{Ir(H)[diphosphine]}(2)(μ-X)(3)]X (diphosphine = (S)-2,2'-bis(diphenylphosphino)-1,1'-binaphthyl [(S)-BINAP], (S)-5,5'-bis(diphenylphosphino)-4,4'-bi-1,3-benzodioxole [(S)-SEGPHOS], (S)-5,5'-bis(...
متن کاملChiral iridium(I) bis(NHC) complexes as catalysts for asymmetric transfer hydrogenation
The common use of NHC complexes in transition-metal mediated C–C coupling and metathesis reactions in recent decades has established N-heterocyclic carbenes as a new class of ligand for catalysis. The field of asymmetric catalysis with complexes bearing NHC-containing chiral ligands is dominated by mixed carbene/oxazoline or carbene/phosphane chelating ligands. In contrast, applications of comp...
متن کاملA new class of versatile chiral-bridged atropisomeric diphosphine ligands: remarkably efficient ligand syntheses and their applications in highly enantioselective hydrogenation reactions.
A series of chiral diphosphine ligands denoted as PQ-Phos was prepared by atropdiastereoselective Ullmann coupling and ring-closure reactions. The Ullmann coupling reaction of the biaryl diphosphine dioxides is featured by highly efficient central-to-axial chirality transfer with diastereomeric excess >99%. This substrate-directed diastereomeric biaryl coupling reaction is unprecedented for the...
متن کاملHighly enantioselective hydrogenation and transfer hydrogenation of cycloalkyl and heterocyclic ketones catalysed by an iridium complex of a tridentate phosphine-diamine ligand.
Ir complexes of chiral phosphine-diamine ligands catalyse the hydrogenation and transfer hydrogenation of aryl-piperidin-4-yl methanones, and ketones bearing both an aryl group and secondary alkyl substituent with up to 98% e.e., and with substrate to catalyst ratios of up to 4000.
متن کاملAsymmetric hydrogenation of isoquinolinium salts catalyzed by chiral iridium complexes: direct synthesis for optically active 1,2,3,4-tetrahydroisoquinolines.
1,2,3,4-Tetrahydroisoquinolines (THIQs), a class of highly important molecular skeletons abundant in natural alkaloids and biologically active compounds, are often used as key intermediates for the synthesis of pharmaceutical drugs and drug candidates. To date, synthetic efforts have focused on introducing chirality at the C1 position with configurational integrity by employing the following sy...
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 51 21 شماره
صفحات -
تاریخ انتشار 2015