Study On The Transition Metal-catalyzed Carbon-sulfur Bondv Formation Reactions Under Green Conditions

This dissertation consists of two parts:Part one:Dinitrogen-functionalized MCM-41anchored copper complexes were conveniently prepared from commercially available3-(2-aminoethylamino)-propyltrimethoxysilane via immobilization on MCM-41, followed by reacting with copper salts such as CuI or CuCl. These supported copper complexes were characterized by XRD, ICP and elemental analysis.Part two:Firstly, we investigated ligand-and solvent-free synthesis of2-aminobenzothiazoles by copper-catalyzed tandem reaction of2-haloanilines with isothiocyanates. It was found that the tandem reactions of a variety of2-iodoanilines with various isothiocyanates proceeded smoothly in the presence of1mol%CuSO4with Bu3N as base, giving corresponding2-aminobenzothiazoles in high yields. Dinitrogen-functionalized MCM-41anchored copper (Ⅰ) complex [MCM-41-2N-CuI] was conveniently prepared by the reaction of MCM-41-2N with CuI. Its catalytic performance in the synthesis of corresponding diaryl sulfides through the reaction of aryliodides with thioacetamide was studied. The reaction of various aryl iodides with thioacetamide proceeded very smoothly in the presence of a catalytic amount of MCM-41-2N-CuI to afford the corresponding symmetrial diaryl sulfides in good to excellent yields at120℃using Cs2CO3as base and DMSO-H2O as solvent. This heterogeneous copper catalyst exhibited high catalytic activity and can be recovered and recycled by a simple filtration of the reaction solution and used for at least5consecutive trials without any decreases in activity. Diphosphino-functionalized MCM-41anchored rhodium (Ⅰ) complex [MCM-41-2P-Rh(Ⅰ)] was conveniently prepared by the reaction of MCM-41-2P with Wilkinson catalyst RhCl(PPh3)3. The reactions of thiols or thiopheols with alkylhalides proceeded very smoothly in the presence of a catalytic amount of MCM-41-2P-Rh(Ⅰ) to give the corresponding sulfides in good to excellent yields using Et3N as base. This heterogeneous rhodium catalyst can be recovered and recycled for at least5consecutive trials without any decreases in activity. The tandem reactions of2-haloanilines, CS2and amines proceeded smoothly in the presence of a catalytic amount of MCM-41-2N-CuCl to afford a variety of2-aminobenzothiazoles in good to excellent yields at110℃using K2CO3as base and DMF as solvent. The heterogeneous copper catalyst exhibited high catalytic activity and can be recovered and recycled by a simple filtration of the reaction solution and used for at least5consecutive trials without any decreases in activity.