A high biocompatible near-infrared fluorescent probe for tracking cysteine in multi-biosystem and its application in cervical cancer imaging.

Cysteine (Cys) plays a crucial role in the biological system and many related diseases. However, the detection of Cys in living organisms are still hindered by shortage of small molecule fluorophores that exhibit excitation and emission in the near-infrared region. Herein, we designed and synthesized a high water-soluble Cys probe (Cy7-SS) based on heptamethine cyanine scaffold.

Study on the Cross-Scale Effects of Microscopic Interactions and Mechanical Properties of Rigid Polyurethane Foam Driven by Negative-Temperature Environments.

In order to investigate the cross-scale effects of the interaction between the hard and soft segments of stiff polyurethane foam on the material's mesoscopic pore structure and macroscopic compression characteristics in various negative-temperature environments, this paper used molecular dynamics to calculate the interaction differences between hard and soft segments in different negative-temperature environments. The effects of various negative-temperature settings on the cell structure of stiff polyurethane foam were investigated using scanning electron microscopy and Image J software. Finally, macro experiments were used to determine the influence of a negative-temperature environment on the characteristics of stiff polyurethane foam (such as compressibility).

TfO-Mediated Direct Synthesis of 4-Sulfenylated Oxazoles from β-Keto Sulfoxides and Nitriles.

A general and efficient method for the synthesis of 4-sulfenylated oxazoles is described. Trisubstituted oxazoles are obtained in good to excellent yields from β-keto sulfoxides and nitriles. The mechanistic study suggests that the reaction proceeds via the nucleophilic addition of nitriles to the in situ formed α-carbonyl cation followed by intramolecular cyclization.

Copper-catalyzed direct sulfenoamination of saturated ketones formed enaminones.

A sequential and efficient protocol for the synthesis of α-thiolated enaminones has been developed using copper-TEMPO systems. This reaction features a broad substrate scope to afford the desired product in good to excellent yields with high stereoselectivity. A preliminary mechanistic study suggests that the formed enaminone acts as the key intermediate.

Switchable Synthesis of Sulfoxides and α-Alkoxy-β-ketothioethers Regulated by Temperature in a Selectfluor-Methanol System.

A switchable and benign protocol for chemoselective synthesis of sulfoxides and α-alkoxy-β-ketothioethers has been developed. It was determined that various thiophenols and alkenes/alkynes are compatible to realize the target compounds from a medium to a high yield by regulating the reaction temperature. In particular, methanol not only served as a solvent but also participated in the reaction process as a hydrogen donor.