Synthesis of I(III)/S(VI) reagents and their reactivity in photochemical cycloaddition reactions with unsaturated bonds.

The development of novel methodologies for the introduction of the sulfoxonium group under mild conditions is appealing but remains underexplored. Herein we report the synthesis of a class of hypervalent iodine reagents with a transferrable sulfoxonium group. These compounds enable mixed iodonium-sulfoxonium ylide reactivity. These well-defined reagents are examined in visible-light-promoted cyclization reactions with a wide range of unsaturated bonds including alkenes, alkynes, nitriles, and allenes. Two distinct cyclization pathways are identified, which are controlled by the substituent of the unsaturated bond. The cycloaddition protocol features simple operation, mild reaction conditions, and excellent functional group tolerance, affording a broad range of sulfoxonium-containing cyclic structures in moderate to excellent yields. Furthermore, the sufoxonium group in the product can be transformed into diverse functional groups and structural motifs via single electron transfer and transition-metal catalysis.

Amorphous zirconium metal-organic frameworks assembled from mixed porphyrins as solvent-free catalysts for Knoevenagel condensation.

Three mixed porphyrins, icpp (1-3), were synthesized via the reactions of 4-formylbenzoic acid and 4-imidazolecarboxaldehyde, and then five amorphous or crystalline Zr-MOFs-SPUZ (1-5) were obtained from icpp (1-3), timp and tcpp, respectively. The catalytic activities of the synthesized porphyrins and MOFs were studied on the Knoevenagel condensation of aldehydes and malononitrile under solvent-free conditions. Among them, amorphous MOF SPUZ-1 showed the highest catalytic activity. Further studies on various aldehydes demonstrated that most reactions were completed with a low catalyst loading (1 mol%) in a short reaction time (5-30 min), and the best result was obtained with the yield of 99.9% within 5 min. Moreover, SPUZ-1 could be recycled 7 times without significant loss of activity.

Development of Janus Cellulose Acetate Fiber (CA) Membranes for Highly Efficient Oil-Water Separation.

A new type of Janus cellulose acetate (CA) fiber membrane was used to separate oil-water emulsions, which was prepared with plasma gas phase grafting by polymerizing octamethylcyclotetrasiloxane (D4) onto a CA fiber membrane prepared by centrifugal spinning. The Janus-CA fiber membrane was described in terms of chemical structure using Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS) analysis, energy dispersive X-ray spectroscopy (EDX) analysis and morphology by field emission scanning electron microscopy (FESEM). In this contribution, we examine the influence of spinning solution concentration, spinning speed and nozzle aperture on the centrifugal spinning process and the fiber morphology. Superhydrophobic/hydrophilic Janus-CA fiber membrane was used to separate water and 1,2-dibromoethane mixture and Toluene-in-water emulsion. Unidirectional water transfer Janus-CA fiber membrane was used to separate n-hexane and water mixture. The separation for the first-time interception rate was about 98.81%, 98.76% and 98.73%, respectively. Experimental results revealed that the Janus cellulose acetate (CA) fiber membrane gave a permeate flux of about 43.32, 331.72 and 275.27 L/(m2·h), respectively. The novel Janus-CA fiber membrane can potentially be used for sustainable W/O emulsion separation. We believe that this is a facile strategy for construction of filtration materials for practical oil-water separation.