A highly efficient and selective[2+2+2]cyclization of diynes and monoalkynes was catalyzed by rhodium under room temperature in water/THF mixed solvent,affording isoindolines and isobenzofurans in good to excellent yi...A highly efficient and selective[2+2+2]cyclization of diynes and monoalkynes was catalyzed by rhodium under room temperature in water/THF mixed solvent,affording isoindolines and isobenzofurans in good to excellent yields.The center atoms (N,O) in the diynes showed a significant effect for the cyclization.展开更多
A highly efficient and regio-/stereoselective method of hydrosilylating terminal alkynes was developed using Pt(DVDS)-tri(t-butyl) phosphine catalyst system at room temperature.Trans-products or alpha-products were ob...A highly efficient and regio-/stereoselective method of hydrosilylating terminal alkynes was developed using Pt(DVDS)-tri(t-butyl) phosphine catalyst system at room temperature.Trans-products or alpha-products were obtained almost exclusively depending on the alkynes and silanes employed.展开更多
THE Yellow River, with its huge amount of silt charge from the Loess Plateau, is the secondlargest river in China. Its lower reach has become a famous hanging river because of serioussilting up, and the magnitude of d...THE Yellow River, with its huge amount of silt charge from the Loess Plateau, is the secondlargest river in China. Its lower reach has become a famous hanging river because of serioussilting up, and the magnitude of discharge changes much from season to season. As a result ofsilting, migration of the stream channel happens frequently. Lateral erosion of channel or pointbars, and scarp slopes forming during the erosion may be often observed. The silt stalactite,hitherto not reported, usually forms on surfaces of the slope. As a newly found kind of sedirnen-tary structure, the silt stalactite may have some significance to the study of sedimentary envi-ronments and paleoclimate.展开更多
文摘A highly efficient and selective[2+2+2]cyclization of diynes and monoalkynes was catalyzed by rhodium under room temperature in water/THF mixed solvent,affording isoindolines and isobenzofurans in good to excellent yields.The center atoms (N,O) in the diynes showed a significant effect for the cyclization.
文摘A highly efficient and regio-/stereoselective method of hydrosilylating terminal alkynes was developed using Pt(DVDS)-tri(t-butyl) phosphine catalyst system at room temperature.Trans-products or alpha-products were obtained almost exclusively depending on the alkynes and silanes employed.
文摘THE Yellow River, with its huge amount of silt charge from the Loess Plateau, is the secondlargest river in China. Its lower reach has become a famous hanging river because of serioussilting up, and the magnitude of discharge changes much from season to season. As a result ofsilting, migration of the stream channel happens frequently. Lateral erosion of channel or pointbars, and scarp slopes forming during the erosion may be often observed. The silt stalactite,hitherto not reported, usually forms on surfaces of the slope. As a newly found kind of sedirnen-tary structure, the silt stalactite may have some significance to the study of sedimentary envi-ronments and paleoclimate.
