Boundedness of Solutions for a Class of Second-Order Periodic Systems

In this paper we study the following second-order periodic system: x′′+V′(x)+p(x,t)=0, where V(x) has a singularity. Under some assumptions on the V(x) and p(x,t) by Ortega’ small twist theorem, we obtain the existence of quasi-periodic solutions and boundedness of all the solutions

Effective Synthesis of Nucleosides Utilizing O-Acetyl-Glycosyl Chlorides as Glycosyl Donors in the Absence of Catalyst: Mechanism Revision and Application to Silyl-Hilbert-Johnson Reaction

An effective synthesis of nucleosides using glycosyl chlorides as glycosyl donors in the absence of Lewis acid has been developed. Glycosyl chlorides have been shown to be pivotal intermediates in the classical silyl-Hilbert-Johnson reaction. A possible mechanism that differs from the currently accepted mechanism advanced by Vorbrueggen has been proposed and verified by experiments. In practice, this catalyst-free method provides easy access to Capecitabine in high yield