[2+2] Photodimerization of Stilbazoles Promoted by Oxalic Acid in Suspension

Fluorinated 2-Azetines: Synthesis, Applications, Biological Tests, and Development of a Catalytic Process

An efficient and straightforward phosphine-promoted tandem aza-Michael addition/intramolecular Wittig reaction was developed for the synthesis of polyfunctionalized 2-azetines. After demonstrating that this transformation could be made catalytic in phosphine through in situ reduction of phosphine oxide with phenylsilane, different post-transformation steps have been demonstrated, including an original [2 + 2] photodimerization. Preliminary biological tests highlighted that these fluorinated 1,2-dihydroazete-2,3-dicarboxylates exhibited significant cytotoxicity against the human tumor cell line.

The synthesis of ortho-stilbazoles (2-styrylpyridines) (microreview)

This microreview compiles methods for the synthesis of ortho-stilbazoles (2-styrylpyridines) described in the literature in 2017-2022. Depending on the synthons from which the target structure is formed, four main synthetic approaches can be distinguished: coupling reactions, Wittig reactions, condensation reactions, and pyridine ring formation reactions.

Halogen-Bond Mediated [2+2] Photodimerizations: À la Carte Access to Unsymmetrical Cyclobutanes in the Solid State

The ditopic halogen-bond (X-bond) donors 1,2-, 1,3-, and 1,4-diiodotetrafluorobenzene (1,2-, 1,3-, and 1,4-di-I-tFb, respectively) form binary cocrystals with the unsymmetrical ditopic X-bond acceptor trans-1-(2-pyridyl)-2-(4-pyridyl)ethylene (2,4-bpe). The components of each cocrystal (1,2-di-I-tFb)·(2,4-bpe), (1,3-di-I-tFb)·(2,4-bpe), and (1,4-di-I-tFb)·(2,4-bpe) assemble via N···I X-bonds. For (1,2-di-I-tFb)·(2,4-bpe) and (1,3-di-I-tFb)·(2,4-bpe), the X-bond donor supports the C=C bonds of 2,4-bpe to undergo a topochemical [2+2] photodimerization in the solid state: UV-irradiation of each solid resulted in stereospecific, regiospecific, and quantitative photodimerization of 2,4-bpe to the corresponding head-to-tail (ht) or head-to-head (hh) cyclobutane photoproduct, respectively.

Stabilized photoemission from organic molecules in zero-dimensional hybrid Zn and Cd halides

This work explores the utilization of a photoactive organic cation for the preparation of R2MCl4 (M = Zn, Cd; R = (E)-4-styrylpyridinium, C13H12N+).

A metal-carbene template approach enables efficient synthesis of a functionalized cage-annulated crown ether

A facile synthetic method to form cage-annulated crown ether with anchored imidazolium units was developed. The present work verified the potential application of the metal-carbene template approach (MCTA) in the preparation of novel flexible polyimidazolium cages by photochemical [2+2] cycloaddition reactions and may provide a new method for the preparation of flexible pure organic cages with incorporation of a variety of functional sites.

pH-Responsive Capsule Polymer Particles Prepared by Interfacial Photo-Cross-Linking: Effect of the Alkyl Chain Length of the pH-Responsive Monomer

pH-responsive capsule particles have immense potential for use in various advanced fields, such as microreactors and drug delivery. Moreover, the interfacial photo-cross-linking of spherical polymer particles is a promising strategy to create various functional capsule particles. In this study, pH-responsive capsule polymer particles were prepared by interfacial photo-cross-linking with photo-reactive polymers possessing different pH-responsive monomer units of different alkyl chain lengths, namely, 2-dimethylaminoethyl methacrylate, 2-diethylaminoethyl methacrylate, and 2-diisopropylaminoethyl methacrylate. Using these different pH-responsive monomers, regulation of the controlled release properties of pH-responsive capsule particles was achieved. All capsule particles prepared from these three different polymers released encapsulated molecules under acidic conditions; however, more acidic conditions were necessary for releasing encapsulated molecules with the increasing alkyl chain length. The afforded results indicated that pH-responsive monomers of different alkyl chain lengths could be successfully employed to regulate the pH-responsive controlled release property of the capsule particles prepared by interfacial photo-cross-linking.