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BackgroundLittle evidence is available about the association between temperature and cerebrovascular mortality in China. This study aims to examine the effects of ambient temperature on cerebrovascular mortality in different climatic zones in China.MethodWe obtained daily data on weather conditions, air pollution and cerebrovascular deaths from five cities (Beijing, Tianjin, Shanghai, Wuhan, and Guangzhou) in China during 2004-2008. We examined city-specific associations between ambient temperature and the cerebrovascular mortality, while adjusting for season, long-term trends, day of the week, relative humidity and air pollution. We examined cold effects using a 1°C decrease in temperature below a city-specific threshold, and hot effects using a 1°C increase in temperature above a city-specific threshold. We used a meta-analysis to summarize the cold and hot effects across the five cities.ResultsBeijing and Tianjin (with low mean temperature) had lower thresholds than Shanghai, Wuhan and Guangzhou (with high mean temperature). In Beijing, Tianjin, Wuhan and Guangzhou cold effects were delayed, while in Shanghai there was no or short induction. Hot effects were acute in all five cities. The cold effects lasted longer than hot effects. The hot effects were followed by mortality displacement. The pooled relative risk associated with a 1°C decrease in temperature below thresholds (cold effect) was 1.037 (95% confidence interval (CI): 1.020, 1.053). The pooled relative risk associated with a 1°C increase in temperature above thresholds (hot effect) was 1.014 (95% CI: 0.979, 1.050).ConclusionCold temperatures are significantly associated with cerebrovascular mortality in China, while hot effect is not significant. People in colder climate cities were sensitive to hot temperatures, while people in warmer climate cities were vulnerable to cold temperature.

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Carbonylation of o-arylanilines utilizing CO2 as a carbonyl source for the synthesis of important phenanthridinones with a free (NH)-lactam motif has been described under metal-free condition. A range of o-arylanilines were transformed to the corresponding phenanthridinones in high yields.

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Lewis base promoted selective reduction of CO2 into boryl formates by using BH3NH3 as a reductant under mild conditions has been reported. The boryl formates, generated in situ, were shown to be reactive and versatile sources of formyl compounds to create new C–N, C–O, and C–C bonds. The reactivity of the boryl formates to yield formic acid, formamides, formates, secondary alcohols, and benzoheterocyclic rings was investigated.

Metal-catalyzed direct deoxygenative C(sp 3 )−C-(sp 2 ) coupling of alcohols is synthetically appealing, but it remains a particular challenge for the synthetic community. Herein, we demonstrate a radical dehydroxylative vinylation reaction of tertiary alcohols by Ti catalysis and, thus, establish a method for the construction of vinylated all-carbon quaternary centers. The reaction proceeds under mild conditions and tolerates various functionalities, including Ar−Bpin, Ar−SiMe 3 , alkyl chloride, phenol, nitrile, ester, furan, and thiophene. The reaction works with various vinyl halides, including fluorides, chlorides, bromides, and iodides. The use of a mixture of trans-and cis-haloalkenes gives the same trans products. The selectivity profiles were investigated among the vinyl and aryl electrophiles and among the different classes of alcohols.

An unprecedented asymmetric Diels–Alder reaction of 2‐vinylindoles with methyleneindolinones has been disclosed. Under bifunctional organocatalysis by cinchona‐derived squaramide catalyst, a series of diversely functionalized carbazolespirooxindole derivatives bearing three contiguous stereocenters are rapidly constructed under mild conditions (48–90% yields, up to >20:1 dr and 99% ee).magnified image