103323-99-5Relevant academic research and scientific papers
Iridium-Catalyzed Enantioselective Hydrogenation of Oxocarbenium Ions: A Case of Ionic Hydrogenation
Lin, Zhenyang,Sun, Yongjie,Wang, Heng,Wen, Jialin,Yang, Tilong,Zhang, Xumu
, p. 6108 - 6114 (2020)
Ionic hydrogenation has not been extensively explored, but is advantageous for challenging substrates such as unsaturated intermediates. Reported here is an iridium-catalyzed hydrogenation of oxocarbenium ions to afford chiral isochromans with high enantioselectivities. A variety of functionalities are compatible with this catalytic system. In the presence of a catalytic amount of the Br?nsted acid HCl, an α-chloroether is generated in situ and subsequentially reduced. Kinetic studies suggest first-order kinetics in the substrate and half-order kinetics in the catalyst. A positive nonlinear effect, together with the half kinetic order, revealed a dimerization of the catalyst. Possible reaction pathways based on the monomeric iridium catalyst were proposed and DFT computational studies revealed an ionic hydrogenation pathway. Chloride abstraction and the cleavage of dihydrogen occur in the same step.
Catalytic asymmetric alkynylation of C1-substituted C,N-cyclic azomethine imines by CuI/chiral bronsted acid co-catalyst
Hashimoto, Takuya,Omote, Masato,Maruoka, Keiji
supporting information; experimental part, p. 8952 - 8955 (2011/10/31)
It all adds up: The title reaction was developed for the synthesis of chiral tetrahydroisoquinoline derivatives with a tetrasubstituted carbon center at the C1-position (see scheme, Bz=benzoyl, pybox=2,6-bis(2-oxazolinyl)pyridine) . The reaction was facilitated effectively by the co-catalyst system composed of copper(I)/Ph-pybox and an axially chiral dicarboxylic acid.
