Anomeric sulfonium ions are attractive glycosyl donors for the stereoselective installation of 1,2-cis glycosides. Although these donors are receiving increasing attention, their mechanism of glycosylation remains controversial. We have investigated the reaction mechanism of glycosylation of a donor modified at C-2 with a (1S)-phenyl-2-(phenylsulfanyl)ethyl chiral auxiliary. Preactivation of this donor results in the formation of a bicyclic β-sulfonium ion that after addition of an alcohol undergoes 1,2-cis-glycosylation. To probe the importance of the thiophenyl moiety, analogs were prepared in which this moiety was replaced by an anisoyl or benzyl moiety. Furthermore, the auxiliaries were installed as S- and R-stereoisomers. It was found that the nature of the heteroatom and chirality of the auxiliary greatly influenced the anomeric outcome and only the one containing a thiophenyl moiety and having S-configuration gave consistently α-anomeric products. The sulfonium ions are sufficiently stable at a temperature at which glycosylations proceed indicating that they are viable glycosylation agents. Time-course NMR experiments with the latter donor showed that the initial rates of glycosylations increase with increases in acceptor concentration and the rate curves could be fitted to a second order rate equation. Collectively, these observations support a mechanism by which a sulfonium ion intermediate is formed as a trans-decalin ring system that can undergo glycosylation through a bimolecular mechanism. DFT calculations have provided further insight into the reaction path of glycosylation and indicate that initially a hydrogen-bonded complex is formed between sulfonium ion and acceptor that undergoes SN2-like glycosylation to give an α-anomeric product.

Aimed at the disadvantages of the traditional energy supply, a method to transfer energy by micro-strip antennas was proposed. The characteristics of microstrip antennas were introduced, and the microstrip antenna used in a monitoring system was designed. A experiment of the microstrip antenna was carried out. The attenuation of transmission, efficiency and matching conditions were analyzed. The results of experiments and analysis show that under the conditions of close range and low power, the method of using microstrip antennas to transfer energy is feasible.