Study On The Lanthanide Chlorides Catalyzed Syntheses Of 2-Aminobenzothiazines And Tetrahydroquinolines

The lanthanide chlorides catalyzed syntheses of several kinds of azaheterocycle are studied in this thesis, which is composed with two parts as follows:1. The 2-aminobenzothiazines were efficiently synthesized by the reactions of o-aminocinnamate and isothiocyanides catalyzed by ytterbium chlorides (YbCl3). The reaction was carried out under mild conditions in the absence of protective gas affording the desired products in excellent yields. The influence of the reaction conditions on yield was examined and the isomerism of the products was discussed.2. Pyrano- and furano[3,2-c]quinolines were efficiently synthesized in high cis-selectivity via gadolinium chloride catalyzed one-pot imino Diels-Alder reactions. The solvent conditions, particularly the type and amount of the solvent, are the predominant factors affecting the stereoselectivity of the products. Besides, the catalytic activity of cationic lanthanide complex on imino Diels-Alder reaction was explored. The comparison between the cationic lanthanide complex and the corresponding neutral lanthanide chloride proved a higher activity of the former.