一價銠金屬催化肉桂胺衍生物進行不對稱氫芳基化反應
Rhodium(I)-Catalyzed Asymmetric Hydroarylation of Cinnamylamine Derivatives
一價銠金屬催化反應已經被廣泛應用於有機化學合成領域中。而本研究以具保護基之肉桂胺衍生物1與四芳基硼鈉試劑2a作為起始物進行銠金屬不對稱氫芳基化催化反應,得到具有保護基的掌性2,3-雙芳基丙胺衍生物3,並探討此反應的掌性雙烯配基對於反應的影響。本研究已完成使用Ts(對甲苯磺醯基)保護基之肉桂胺衍生物1a作為起始物進行反應,並改變與銠金屬錯合的配基,發現當配基使用2,5號位為芳基取代之配基L(掌性雙環[2,2,1]雙烯配基)時,反應有較好的位置選擇性,其中最佳的是芳基取代為苯基之配基L1,其位置選擇性比例為1:0:0.09。目前將進行改變起始物1之氮上的保護基,以L1作為配基進行反應,並與1a比較,優化反應性及產率。
Development and Comparison of a Small-Scale Toroidal Horizontal-Axis Wind Turbine to a Conventional HAWT Design
Wind energy is one of the most promising and rapidly growing sources of renewable energy, although maximizing its efficiency while minimizing noise remains a challenge and limits its widespread adoption. The emergence of toroidal propellers, which have gained popularity for producing comparable thrust levels to traditional drone propellers while producing less noise, could mitigate this. This study aimed to develop a small-scale toroidal HAWT and compare its power and noise output to a conventional rotor design under similar wind velocity conditions. 15-centimeter diameter models of the toroidal and conventional rotors were created in Fusion 360 and simulated using Ansys Fluent to identify the significant aerodynamic characteristics that positively affect the blades’ power coefficient. The toroidal design with the greatest simulated power output at low tip speed ratios (TSRs) was then 3D printed and physically tested in a wind tunnel against the control rotor. The experimental results confirmed that the toroidal design had greater power coefficients at lower TSRs compared to the control rotor. The toroidal rotor started operating at a wind velocity of 3 m/s compared to the control rotor’s 6 m/s, which indicates superior start-up characteristics. While the toroidal rotor produced half the power output of the control at the highest tested wind speed of 7 m/s, it emitted 18 decibels less noise and showed a reduction in discernible noise between frequencies of two to five kilohertz. The results from this study show its potential in low-noise wind turbines within low-wind velocity environments.