Chiral-Boron-Complex-Catalyzed Asymmetric [3 + 2] Cycloaddition of ß-Trifluoromethyl α,ß-Unsaturated Ketones with N,N'-Cyclic Azomethine Imines.

The (R)-3,3'-(3,5-(CF3)2-C6H3)2-BINOL-boron-complex-catalyzed asymmetric 1,3-dipolar cycloaddition of ß-trifluoromethyl α,ß-unsaturated ketone with N,N'-cyclic azomethine imines was developed to afford N,N'-bicyclic pyrazolidine derivatives bearing a stereogenic carbon center containing CF3 motifs in high yields with excellent diastereo- and enantioselectivities (up to >20:1 dr, and >99% ee). This catalytic system features mild reaction conditions, high efficiency, and a broad substrate scope.

Chiral-Boron-Complex-Catalyzed Asymmetric [3 + 2] Cycloaddition of 2'-Hydroxychalcones with N,N'-Cyclic Azomethine Imines.

We report the (R)-3,3'-I2-BINOL-boron-complex-catalyzed asymmetric 1,3-dipolar cycloaddition of 2'-hydroxychalcones with N,N'-cyclic azomethine imines, providing the corresponding N,N'-bicyclic pyrazolidine derivatives with three contiguous tertiary stereocenters in high yields with excellent diastereo- and enantioselectivities (up to >99:1 diastereomeric ratio and >99% enantiomeric excess). This catalytic system exhibits advantages of mild reaction conditions, high efficiency, and broad substrate scopes.

[Identification of the polymorphs of clopidogrel bisulfate based on the steric morphology parameters of crystals].

The crystal form of solid substance had intrinsic correlation with its three dimensional crystal morphology. Based on the characterization of the three dimensional crystal morphology of clopidogrel bisulfate, this research is to establish a model based on the three dimensional morphological parameters. The granular samples composed of polymorphs of clopidogrel bisulfate and microcrystalline cellulose (MCC) were scanned by synchrotron radiation X-ray microscopic CT technology (SR-microCT) and the three dimensional structural models for which were constructed. Seven groups of three dimensional morphological parameters were calculated. Finally, the mathematical model was established with the multi-layer perception (MLP) artificial neutral network methods to identify and predict the polymorphs of clopidogrel bisulfate. The success rate of the model prediction for the polymorphs of clopidogrel bisulfate was 92.7% and the area under the ROC curve was 96.2%. The polymorphs of drugs could be identified and predicted through the numerical description of the three dimensional morphology. The volume, number of the vertices and the surface area were the major determinants for the identification of the polymorphs of clopidogrel bisulfate.