Visible-Light-Promoted 6π Photocyclization of -Biaryl-Appended β-Ketoesters.

A photocatalyst- and additive-free visible-light-induced 6π-photocyclization of -biaryl-appended β-ketoesters has been developed. Upon irradiation with visible light, substrates undergo 6--trig cyclization/1,5-H shift to 9,10-dihydrophenanthren-9-ols with high efficiency and selectivity. The reaction proceeds conrotatory ring closure followed by a suprafacial 1,5-hydrogen shift leading to the observed single -fused products.

The release inhibition of organic substances from microplastics in the presence of algal derived organic matters: Influence of the molecular weight-dependent inhibition heterogeneities.

As the emerging contaminants, the behavior and fate of microplastics (MPs) were highly related to the interactions with surrounding organic matters. However, information on the effects of molecular sizes of organic matters on the interaction is still lacking. In this study, the bulk algal-derived organic matter (AOM) samples were obtained and further fractionated into high molecular weight (HMW-, 1kDa-0.