3D chirality of sandwich type of organic molecules has been discovered. The key element of this chirality is characterized by three layers of structures that are arranged nearly in parallel fashion with one on top and one down from the center plane. Individual enantiomers of these molecules have been fully characterized by spectroscopies with their enantiomeric purity measured by chiral HPLC. The absolute configuration was unambiguously assigned by X-ray diffraction analysis. This is the first multilayer 3D chirality reported and is anticipated to lead to a new research area of asymmetric synthesis and catalysis and to have a broad impact on chemical, medicinal, and material sciences in future.

An I2/KI-mediated oxidative N-N bond formation reaction is described. This new and environmentally benign approach allows for the convenient synthesis of a variety of 1,2,4-triazolo[1,5-a]pyridines and other 1,5-fused 1,2,4-triazoles from readily available N-aryl amidines in an efficient and scalable fashion.

The first enantioselective assembly of sandwich-shaped organo molecules has been achieved by conducting dual asymmetric Suzuki-Miyaura couplings and nine other reactions. This work also presents the first fully C-C anchored multi-layer 3D chirality with optically pure enantiomers. As confirmed by X-ray diffraction analysis that this chiral framework is featured by a unique C2-symmetry in which a nearly parallel fashion consisting of three layers: top, middle and bottom aromatic rings. Unlike the documented planar or axial chirality, the present chirality shows its top and bottom layers restrict each other from free rotation, i.e., this multi-layer 3D chirality would not exist if either top or bottom layer is removed. Nearly all multi-layered compounds showed strong luminescence of different colors under UV irradiation, and several randomly selected samples displayed aggregation-induced emission (AIE) properties. This work is believed to have broad impacts on chemical, medicinal and material sciences including optoelectronic materials in future.

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A new strategy has been established for the synthesis of functionalized chromene and chroman derivatives via a Cs 2 CO 3 -catalyzed domino addition of 2′-hydroxychalcone derivatives with allenoates, which can serve as a general avenue for the construction of multireplaced chromene derivatives. Chemoselectivity of this synthesis was found to depend on substituents on substrates. Good to excellent yields were achieved under simple and mild conditions at room temperature.