Xinsheng Lei

Cs2CO3-promoted defluorination and functionalization of α-CF3 carbonyl compounds in the presence of N-, O-, and/or S-nucleophiles

A simple, efficient, and mild method for defluorination and functionalization of 3,3,3-trifluoro carbonyl compounds has been developed. In the present method, Cs2CO3 can easily convert α-trifluoromethyl esters, amides, and ketones into β,β-S-, O- and/or N-substituted α,β-unsaturated carbonyl compounds in the presence of N-, O-, and S-nucleophiles with moderate to excellent yields, and furthermore, this transformation with α-trifluoromethyl ester and a series of 2-aminophenols can result in benzooxazoles in good yields.

An improved and scalable synthesis of zolpidem via a CuI/BINOL-mediated tandem reaction of imine and alkyne

Abstract An improved and scalable method for the synthesis of zolpidem (1), a hypnotic drug, was developed. A two-step sequence involving imine formation and subsequent tandem reaction between an imine and propiolamide in the presence of CuI/BINOL, an efficient promoter for the tandem reaction, is described. Zolpidem was efficiently prepared in a 54% isolated yield and the hemitartrate salt of zolpidem was produced in 37% yield by simple crystallization, without tedious column chromatography. The procedure can be scaled up to >10 g. The yield of 1 increased to 83% following isolation of the intermediate imine 5.

Synthesis of ∆3-2-Hydroxybakuchiol Analogues and Their Growth Inhibitory Activity against Rat UMR106 Cells

A series of ∆3-2-hydroxybakuchiol analogues have been synthesized and tested for their growth inhibitory activity against rat UMR106 cells by using the MTT method. Some of them exhibit enhanced activities compared with the natural product, and the preliminary SAR profile shows that the chain tail on the natural product could be subtly modified to enhance the activity and the aromatic moiety or the terminal olefin on the main chain can also be modified without any evident loss of activity. The stereo-configuration of the quaternary chiral center has an important influence on the activity.