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The umpolung activity of hemiacetals serving as α-carbon nucleophiles has been reported via dinuclear zinc cooperative catalysis. This umpolung strategy has been applied to catalytic asymmetric tandem reactions of 1-tosylindoline-2,3-diols with β,γ-unsaturated-α-keto compounds, providing a broad series of structurally diverse tetrahydrofuran spirooxindoles and dihydrofurans, respectively. In addition, products could be transformed to quinazoline and quinoline derivatives.

An enantioselective Michael/transesterification tandem reaction of α-hydroxy indanones with ortho-ester chalcones was realized using dinuclear zinc catalysts. A series of enantiomerically pure spiro[indanone-2,3′-isochromane-1-one] derivatives were obtained in good yields with excellent stereoselectivities (up to >20 : 1 dr, up to >99% ee). This protocol could be conducted on a gram scale without affecting its stereoselectivities. In addition, the absolute stereochemistry of the products was determined by X-ray crystallographic analysis of 3ac, and a positive nonlinear effect was observed. Finally, a possible catalytic cycle was proposed to explain the origin of the enantioselectivity.

A highly efficient method for the enantioselective build of spiro[1-indanone-5,2'-γ-butyrolactones] has been developed through the tandem Michael/transesterification reaction of α-hydroxy-1-indanone and α,β-unsaturated esters. A broad range of spiro(1-indanone-butyrolacones) with contiguous stereocenters have been synthesized with excellent stereoselectivities (up to >20:1 dr, up to >99% ee) under the catalysis of dinuclear zinc complex. Moreover, the reaction can be run on a gram scale without affecting its stereoselectivities. A possible mechanism is proposed.

A new, efficient route for the enantioselective construction of bispirotetrahydrofuran oxindoles is described via the cooperative dinuclear zinc-AzePhenol catalyst. Under mild conditions, a broad range of bispirotetrahydrofuran oxindoles have been synthesized with excellent stereoselectivities through the cascade Michael/hemiketalization/Friedel-Crafts reaction of β,γ-unsaturated α-ketoamide and 2-hydroxy-1-indanone. The reaction can be performed on a gram scale with low catalyst loading (2 mol %) without impacting its efficiency.

The asymmetric phospha-Michael addition of dialkyl phosphite to α,β-unsaturated carbonyl compounds by using an azetidine-derived dinuclear zinc catalyst was described. The catalyst was proved to be general and efficient for a broad spectrum of enones and α,β-unsaturated N-acylpyrroles. A series of phosphonate-containing compounds were generated with excellent enantioselectivities (up to 99% ee) and chemical yields (up to 99%) under mild conditions without using additives. The products were obtained with more than 95% ee for 23 examples of α,β-unsaturated carbonyl compounds. A positive nonlinear effect was observed and the possible mechanism was proposed.

A series of new nonsymmetric semi-azacrown ether ligands were developed and applied to the asymmetric Michael/cyclic keto-imine formation/Friedel-Crafts alkylation reactions of 3-amino oxindole hydrochlorides and β,γ-unsaturated α-keto amides. A diversity of 2,5-pyrrolidinyl dispirooxindoles containing two nonadjacent spiro-quaternary stereocenters were obtained in excellent diastereoselectivities and moderate to excellent enantioselectivities (up to 95% ee). A possible catalytic cycle was proposed to explain the origin of the asymmetric induction.

A highly enantioselective Friedel-Crafts (F-C) alkylation of pyrrole with a wide range of simple nonchelating chalcone derivatives catalyzed by a chiral (Zn2EtL)n (L = (S,S)-1) complex has been developed. The catalyst (Zn2EtL)n complex was prepared in situ by reacting the chiral ligand (S,S)-1 with 2 equiv of diethylzinc. A series of β-pyrrole-substituted dihydrochalcones were usually formed mostly in excellent yields (up to 99%) and excellent enantioselectivity [up to 99% enantiomeric excess (ee)] by using 15 mol % catalyst loading under mild conditions. The absolute stereochemistry of the products was determined to be the S-configuration by X-ray crystallographic analysis of 13g. Meanwhile, a weak negative nonlinear effect was observed. On the basis of the experimental results and previous reports, a possible mechanism was proposed to explain the origin of the asymmetric induction.

A general AzePhenol dinuclear zinc catalytic system has been successfully developed and introduced into the asymmetric addition of dimethylzinc and alkynylzinc to aromatic aldehydes. In this system, an azetidine derived chiral ligand has proven to be an effective enantioselective promoter. Under the optimal reaction conditions, a series of chiral 1-hydroxyethyl (up to 99% ee) and secondary propargylic alcohols (up to 96% ee) were generated with good yields and enantioselectivities. Additionally, this novel catalytic system showed good functional group compatibility. Remarkably, the substituent's electronic nature alone is not sufficient to allow for exclusive enantioselectivity, an additional substituent's location also had an effect. We proposed that the formation of a stable and structural rigid transition state by the chelation of ortho substituted benzaldehydes to the zinc atom was responsible for the observed higher enantioselectivity. The possible catalytic cycles of both transformations accounting for the stereoselectivity were described accordingly.

A kinetic system correlating the enantioselectivity with a catalyst’s conformational equilibrium, as a theoretical basis for the evaluation, design, and prediction of chiral ligand, is described for the addition of diethylzinc to benzaldehyde, and more importantly, a quantitative relationship between the conformations and the enantioselectivity is derived from this catalytic asymmetric kinetic system, which interprets that the observed enantioselectivity is not a weighted average of the enantioselectivity of the individual conformers.

Magnetospheric relativistic electrons can destroy on-orbit spacecrafts completely by internal charging and discharging effects. As the characteristics and physical mechanism of this space particle are still unclear, magnetospheric relativistic electrons have always been an important object of space environment exploration and space science research. For studying the physical mechanisms and developing models relating to magnetospheric relativistic electrons, it is necessary to use the observations from different satellites and detectors at the same time. Eliminating the systematic deviation between different detection systems to assimilate the observations from different sources is essentially required by such researches. In this work, the on-orbit cross-calibration and assimilation for relativistic electron (> 2 MeV) observations from FengYun 4A and GOES-13 are performed. In this work, only the observations obtained under very quiet geomagnetic conditions (Kp < 2) are adopted to ensure that the objects of study are the radiation belt particles, which are stably captured by the geomagnetic field. According to the physical characteristics of the radiation belt particles, that is, the three adiabatic invariants, and based on the Liouville theorem, the phase space density of the stably captured particles is unchanged. In this paper, the relativistic electron flux data of energy > 2 MeV and instrument pitch angle are in the east and west direction respectively. If the particles’ energy is the same, then their corresponding μ values are the same, and their particles’ directions are the same, then their corresponding J values are the same, and the Liouville theorem can be simplified as the drift shell Lm is the same, the fluxes are the same, and the electron fluxes observed by the two satellites are compared in the drift shell Lm coordinate. The systematic deviation between the two satellites’ relativistic electronic observations can be obtained. According to this result, the data assimilation is carried out, and the results show that the system deviation can be removed well. By this research work, the systematic deviation between two important relativistic electron detection systems in geosynchronous orbit is obtained. Based on the obtained systematic deviations, the assimilations for observations from the two detection systems are achieved. This work lays a solid foundation for the follow-up theoretical and applied researches, and also provides the methods for on-orbit cross-calibration and observation assimilation which could be referred to when other electronic observations on geosynchronous orbit are dealt with.

The kinetics and morphology of polyaniline film prepared by using ammonium persulfate (APS) as oxidant and dodecylbenzoyl sulfonic acid (DBSA) as both emulsifier and dopant were studied in this paper. The kinetics of the formation of polyaniline film was determined by using the quartz crystal microbalance (QCM), and the film morphology was characterized by scanning electron microscopy (SEM). The reaction exhibited half-order kinetics with respect to APS concentration and first-order kinetics with respect to aniline concentration. The activation energy is 41.15 kJ/mol, and the growth rate of PANI film increased with increasing temperature and decreased with increasing concentration of DBSA.

A novel chiral azetidine-based ligand is synthesized and applied to a highly enantioselective Friedel—Crafts alkylation of pyrrole.