Indoor location and intelligent control system can bring convenience to people’s daily life. In this paper, an indoor control system is designed to achieve equipment remote control by using low-energy Bluetooth (BLE) beacon and Internet of Things (IoT) technology. The proposed system consists of five parts: web server, home gateway, smart terminal, smartphone app and BLE beacons. In the web server, fingerprint matching based on RSSI stochastic characteristic and posture recognition model based on geomagnetic sensing are used to establish a more efficient equipment control system, combined with Pedestrian Dead Reckoning (PDR) technology to improve the accuracy of location. A personalized menu of remote “one-click” control is finally offered to users in a smartphone app. This smart home control system has been implemented by hardware, and precision and stability tests have been conducted, which proved the practicability and good user experience of this solution.
A class of C 2 -symmetric chiral spirocyclic phasetransfer catalysts based on tetramethyl-1,1′-spirobiindane scaffold was synthesized from commercially available bisphenol A in 12 steps with 22−25% total yields, which features a more rigid and stable backbone and smaller dihedral angles and can be easily modified. These catalysts show high catalytic performance in the asymmetric alkylation of tert-butyl glycinate Schiff base at only 2 mol % catalyst loading, giving the target products with up to 92% yield and 98% ee.
A chiral spirocyclic quaternary ammonium salt catalyzed asymmetric alkylation of unactivated amides under homogeneous conditions has been developed, giving the target products with up to 60% ee. This novel methodology provides a general and concise protocol for asymmetric α-functionalization of unactivated amides.
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