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Arene- and heteroarene-fused rings are pervasive in biologically active molecules. Direct annulation between a C–H bond on the aromatic core and a tethered alkyl moiety provides a straightforward approach to access these scaffolds; however, such a strategy is often hampered by the need of special reactive groups and/or less compatible cyclization conditions. It would be synthetically appealing if a common native functional group can be used as a handle to enable a general C–H annulation with diverse aromatic rings. Here, we show a deacylative annulation strategy for preparing a large variety of aromatic-fused rings from linear simple ketone precursors. The reaction starts with homolytic cleavage of the ketone α C–C bond via a pre-aromatic intermediate, followed by a radical-mediated dehydrogenative cyclization. Using widely available ketones as the robust radical precursors, this deconstructive approach allows streamlined assembly of complex polycyclic structures with broad functional group tolerance. Common native functional groups would be appealing as handles to enable C–H annulation with diverse aromatic rings. Now, this is achieved using ketones as unconventional alkyl radical precursors providing a practical method to synthesize biologically important fused-ring systems.

Rhodium(III)-catalyzed coupling between ketoximes and alkynes via C-H activation and annulation typically followed the [4+2] selectivity to afford isoquinolines. By designing alkynes bearing a highly electron-withdrawing group and under substrate control, we have successfully switched the selectivity of the coupling between oximes and alkynes to the alternative [3+2] annulation, leading to the efficient synthesis of indenamines. This process features good regioselectivity for both substrates, high efficiency, broad substrate scope, and excellent functional group tolerance.

Based on statistical data about Sand and Dust Storms (SDS) and their associated dustfall, features of temporal and spatialdistribution were studied first in this article. SDS and associateddustfalls occurred most often in northern China, especiallynorthwestern China. However, in the last two years, they have atendency to occur on the central and western parts of the Inner Mongolia Autonomous Region. As a result, Beijing is now among the impact areas, and the Chinese government is paying greaterattention to the matter. The changing trends of SDS and associated dustfalls were subsequently analyzed. Occurrences were seen to be decreasing with the feature of fluctuation duringthe period of 1954–2001, but they have slightly increased since 2000. Also, climate factors related to SDS and associated dustfalls were discussed. Finally, it was recommended that methods to predict SDS in China be further studied in the future.