67907-60-2Relevant articles and documents
Cyclometalated Half-Sandwich Iridium(III) Complexes: Synthesis, Structure, and Diverse Catalytic Activity in Imine Synthesis Using Air as the Oxidant
Li, Rong-Jian,Ling, Chun,Lv, Wen-Rui,Deng, Wei,Yao, Zi-Jian
, p. 5153 - 5162 (2021/05/04)
Four air-stable cyclometalated half-sandwich iridium complexes 1-4 with C,N-donor Schiff base ligands were prepared through C-H activation in moderate-to-good yields. These complexes have been well characterized, and their exact structure was elaborated on by single-crystal X-ray analysis. The iridium(III) complexes 1-4 showed good catalytic activity in the imine synthesis under open-flask conditions (air as the oxidant) from primary amine oxidative homocoupling, secondary amine dehydrogenation, and the cross-coupling reaction of amine and alcohol. Substituents bonded on the ligands of the iridium complexes displayed little effect on the catalytic efficiency. The stability and good catalytic efficiency of the iridium catalysts, mild reaction conditions, and substrate universality showed their potential application in industrial production.
Air-Stable Half-Sandwich Iridium Complexes as Aerobic Oxidation Catalysts for Imine Synthesis
Deng, Wei,Fan, Xiao-Nan,Ou, Hui-Dan,Yao, Zi-Jian
supporting information, (2020/04/02)
Several N,O-coordinate half-sandwich iridium complexes, 1-5, containing constrained bulky β-enaminoketonato ligands were prepared and clearly characterized. Single-crystal X-ray diffraction characterization of these complexes indicates that the iridium center adopts a distorted octahedral geometry. Complexes 1-5 showed good catalytic efficiency in the oxidative homocoupling of primary amines, dehydrogenation of secondary amines, and the oxidative cross-coupling of amines and alcohols, which furnished various types of imines in good yields and high selectivities using O2 as an oxidant under mild conditions. No distinctive substituent effects of the iridium catalysts were observed in these reactions. The diverse catalytic activity, broad substrate scope, mild reaction conditions, and high yields of the products made this catalytic system attractive in industrial processes.
Time-Dependent Switching of Constitutional Dynamic Libraries and Networks from Kinetic to Thermodynamic Distributions
He, Meixia,Lehn, Jean-Marie
supporting information, p. 18560 - 18569 (2019/11/21)
The distribution of the constituents of a constitutional dynamic library (CDL) may undergo time-dependent changes as a function of the kinetics of the processes generating the CDL from its components. Thus, the constitutional dynamic network (CDN) representing the connections between the constituents changes from a kinetic distribution to the thermodynamic one as a function of time. We investigated the behavior of dynamic covalent libraries (DCLs) of four constituents generated by reversible formation of C═N bonds between four components, 2 aldehydes and 2 amino compounds, both in absence and in the presence of metal cations. The associated [2 × 2] networks underwent time-dependent changes from the initial kinetic distribution to the final thermodynamic one, involving an orthogonal switch from one diagonal to the other diagonal of the square [2 × 2] network leading to a very large change in distribution. The DCL constituents could be switched from kinetic products (imines) to thermodynamic products (oximes or acylhydrazones) based on the reactivities of the components and the thermodynamic stabilities of the constituents without addition of any external effector, solely on the basis of the intrinsic properties of the self-contained system. Such processes were achieved for purely organic DCLs/CDNs as well as for inorganic ones containing two metal cations, the latter changing from the silver(I) complex of an imine (kinetic product) to the zinc(II) complex of a hydrazone (thermodynamic product). The results bear relationship to out-of-equilibrium systems concerning kinetic behavior in adaptive chemistry.
