A bisthienylethene-dipyrimido[2,1-b][1,3]benzothiazole (BTE-2PBT) triad has been designed and synthesized based on our recent discovery of PBTs as atypical propeller-shaped novel AIEgens. The triad not only maintains the photochromic properties of BTE moiety in solution, film, and solid state but also exhibits remarkable AIE properties. Moreover, the fluorescence of BTE-2PBT PMMA film could be modulated with high contrast by alternate UV and visible light irradiation. Photoerasing, rewriting, and non-destructive readout of fluorescent images on BTE-2PBT PMMA film well demonstrate its potential application as optical memory media.

5-Hydroxymethyl-2′-deoxycytidine (5hmdC) phosphoramidite and triphosphate are important building blocks in 5hmdC-containing DNA synthesis for epigenetic studies. However, efficient and practical methods for the synthesis of these compounds are still limited. The current research provides an intensively improved synthetic method that enables the preparation of commercially available cyanoethyl-protected 5hmdC phosphoramidite with an overall yield of 39% on 5 g scale. On the basis of facile and efficient accesses to cyanoethyl protected-5hmdU and 5hmdC intermediates, two efficient synthetic routes for 5hmdC triphosphate were also developed.

Hafnium(IV) triflate (Hf(OTf)4) has been identified as a potent catalyst for the direct three-component synthesis of β-carbamate ketones. This new method, featuring a low catalyst loading, fast reaction rate, and solvent-free conditions, provided facile access to a diversity of carbamate-protected Mannich bases. A mechanistic investigation indicated that the three-component reaction proceeds via sequential aldol condensation and aza-Michael addition, but not the Mannich-type pathway.

An efficient method based on peroxo-Mo(VI)/Mo(VI) redox cycle for ambienttemperature synthesis of quinazolin-4(3H)-ones has been developed. Catalytic phosphomolybdic acid (PMA) exhibits Lewis acid and oxidative dehydrogenation activities at different phases of the reaction, and the true oxidative catalytic species was identified as peroxo-Mo(VI) Keggin cluster. Surprisingly, we found that aggregation-induced emission (AIE) is a generic property that has long been neglected for quinazolin-4(3H)-ones. Theoretical calculation results well rationalized their photophysical behaviors and elucidated their AIE mechanism as restriction of access to dark state (RADS). The crystallographic analysis of two representative quinazolin-4(3H)-ones not only revealed their packing mode and weak intermolecular actions but also supported the molecular conformations obtained by theoretical calculations.

We wish to report the preparations of the first medium-sized cyclic aso compounds possessing trans-aso linkages, namely, trans-1,2-diaza-1-cyclooctene (A), trans-3,8-dimethyl-trans-1,2-diaza-1-cyclooctene (11, trans-l,Z-diaza-lcyclononene (2) and trans-1,2-diasa-1-cyclodecene (4). Irradiation of o&-1,2diasa-1-cyclooctene (2)' for 10 hrs resulted in a 60% conversion to its isomer a, which was purified by chromatography over Florisil. The photoisomerisation, 3 which was shown to be reversible by irradiation of pure& (Scheme I), can be followed by nmr. The a-methylene protons of 2 appear as a triplet at 5.80 T, whereas the a-methylene protons of J are magnetically nonequivalent,