The Application Of Thiamine Hydrochloride In Green Organic Synthesis And The Preparation And Modification Of Arctigenin

This thesis consists of three parts. The first part reports thiamine hydrochloride (VB1) as an efficient and reusable catalyst for organic synthesis. The second one, VB1-Al2O3 acidic efficiently catalyzes the one-pot multi-component reaction. In the last one gives the isolation of arctigenin from Arctium lappa, and a series of arctigenin derivatives are synthesized by modification of arctigenin.Green chemistry is a new branch of knowledge over the last 10 years and'atom economy'has been regarded as a principle of green chemistry. Unnecessary derivatization (use of blocking groups, protection, deprotection, temporary modification of physical/chemical processes) should be minimized or avoided if possible, because such steps require additional reagents and can generate waste. We have described a simple, efficient and practical procedure for synthesis of amidoalkyl naphthols, 1,2-dihydro-l-aryl-naphtho[1,2-e][1,3]oxazine-3-ones, and aryl-14-H-dibenzo[a,j]xanthenes using VB1 as a novel catalyst. We also find VB1 is an efficient catalyst for Mannich reaction, formylation reaction of amines, Biginelli type reaction, and Hantzsch reaction. VB1 is cheap, non-toxic, stable, and can be recovered, therefore, it is the most instructive subject for the study of VB1 as a novel organocatalyst.Heterogeneous catalysis means reactants and catalysts are incomplete in the same phase in the reaction process. In recent years, heterogeneous catalysis has received considerable attention because heterogeneous catalyst is easy to separate, less corrosive, easy to cell-coupling with other processes, and high efficiency. We find that VB1-Al2O3 acidic is an efficient heterogeneous catalyst for the synthesis of and 8,9,10,12-tetrahydro-benzo[a]xanthen-11-one andβ-amido ketones. Furthermore, the catalyst can be recovered conveniently and reused efficiently.Arctium lappa is a traditional Chinese medicine, and it possesses a variety of biological activities. Lignans are major components of Arctium lappa, and the content of arctigenin is highest among these lignans. Arctigenin has attracted considerable interest recently because it exbibits significant biological activities, such as antitumor, antiviral, enhance immune function, GVL, regulates blood sugar level, ticlopidine, anti-Alzheimer's, and treatment of nephropathy. We optimize the isolation technology of arctigenin, and obtain the arctigenin in 3% yield. Moreover, a series of arctigenin derivatives are synthesized by using arctigenin as substrate, and the research of biological activities of arctigenin derivatives is ongoing.