An efficient FeCl3-catalyzed substitution reaction of propargylic acetates with enoxysilanes under mild conditions to afford corresponding gamma-alkynyl ketones has been developed. The substitution reaction is followed by a TsOH-catalyzed cyclization without purification of the gamma-alkynyl ketone intermediates, offering a straightforward synthetic route to tri- or tetrasubstituted furans.

A novel and efficient procedure for the synthesis of g-alkynyl ketones by the nucleophilic substitution of propargylic acetates with enoxysilanes in the presence of a catalytic amount of Copper(II) triflate, has been developed. The substitution reaction can be followed by a 4-toluenesulfonic acid-catalyzed cyclization without purification of the g-alkynyl ketone intermediates, offering a straightforward synthetic route to polysubstituted furans.

Environmental air pollution has become an important threat to human health. As one of the major air pollutants, atmospheric particulates have received attention widely. In which, ultrafine particulate matters (UPM) with diameter below 0.1μm have become the main components of ambient air particulates, posing a serious threat to the health of the organism. Therefore, this paper investigated and summarized the research on ultrafine particles at home and abroad, systematically analysed the sources of UPM in ambient air, investigated its toxicological effects of ultrafine particles on the respiratory system, cardiovascular system, and central nervous system of organisms. This study will provide a theoretical reference for environmental air protection and pollution control in China.

Air pollution is an important threat to human health. Atmospheric particulate matters (PM), as one of the major air pollutants, have received increasing attentions in previous studies. Longtime exposure to PM especially the ultrafine particulate matters (UPM) smaller than 0.1 micrometers which can go directly to the alveoli of the lungs, has become a major health hazard. In this study, we investigated UPM pollution to analyze its source, composition and distribution characteristics of UPM in ambient air. We also summarized the existing detection technologies for UPM and analyzed their advantages and disadvantages. This study will provide a theoretical reference for environmental air protection and pollution control in China.