Visible light-induced alkylpyridylation of styrenes via a reductive radical three-component coupling.

A visible light-induced and metal-free strategy for the intermolecular three-compoment alkylpyridylation of styrenes is reported. Hantzsch ester was found to be key to initiate the overall reductive radical coupling reaction. This radical process realized difunctionalization of styrenes, selectively yielding alkylated pyridines in good to excellent yields with a wide tolerance of functional groups, mild reaction conditions and simple operation. This new reaction complements existing visible light-induced variants of styrenes with NHP esters and expands the capabilities of radical-based cross-coupling reactions of pyridines.

Iodine(iii)-mediated intramolecular sulfeno- and selenofunctionalization of ß,γ-unsaturated tosyl hydrazones and oximes.

A cascade radical cyclization/sulfenylation or selenylation of ß,γ-unsaturated hydrazones and oximes was realized under mild conditions with phenyliodine(iii) diacetate (PIDA) as the sole oxidant, leading to the construction of diversely functionalized heteroatom-containing pyrazoline and isoxazoline derivatives. This metal-free radical process is suggested to encompass a sequential C-N/O and C-S/Se bond fomation.

Photocatalytic radical cyclization of α-halo hydrazones with ß-ketocarbonyls: facile access to substituted dihydropyrazoles.

A mild and efficient method for the photocatalytic radical cyclization of α-halo hydrazones with ß-ketocarbonyls has been described. This strategy provides a potential protocol for the construction of functionalized 4,5-dihydropyrazoles in moderate to high yields.

Diversity of House Dust Mite Species in Xishuangbanna Dai, a Tropical Rainforest Region in Southwest China.

PURPOSE: To survey the species diversity of home dust mites (HDM) in Xishuangbanna, a tropical rainforest region in Southwest China. METHODS: From August 2010 to January 2011, mite-allergic patients and healthy controls were invited to participate. Dust samples from the patients' homes were collected, and mites in the samples were isolated. Permanent slides were prepared for morphologically based species determination. RESULTS: In total, 6316 mite specimens of morphologically identifiable species were found in 233 dust samples taken from 41 homes. The result shows that the mite family of Pyroglyphidae occupied the highest percentage of the total amount of mites collected, followed by Cheyletidae family. The most common adult Pyroglyphidae mites were Dermatophagoides (D.) farinae, D. pteronyssinus, and D. siboney. The most common mites found from other families were Blomia tropicalis, Tyrophagus putrescentiae, and Aleuroglyphus ovatus. Four main allergenic dust mite species D. farinae, D. pteronyssinus, D. siboney, and Blomia tropicalis were found to be coinhabiting in 6/41 homes. CONCLUSION: The HDM population in homes in Xishuangbanna, a tropical rainforest region in Southwest China, has its own characteristics. It has rich dust mite species and the dust mite densities do not show significant variation across seasons.