A Study On Mg-mediated Homoallyl Silyetherization, Olefination, Cyclization Of Carbonyl Compounds

Since the discovery of Grignard reagents in organic-metal synthesis, it played a major role with extraordinary worthiness of research as a reaction system. In recent years, the applications of magnesium-promoted reaction have become a considerable value in use as new research focus in organic synthesis, Several advantages have mild conditions, the quick speed of reaction, region selectivity and solid selectivity. So it is a kind of synthesis reagents with considerable applicable value and applicable prospect. For the development of more moderate synthetic technology is important in moving towards chemical sustainable processes. Our group from the view of green chemistry reported that now found the new reactions, magnesium mediated carbonyl compounds with aryl or alkyl halides for carbon-carbon bonds carbon- oxygen formation reactionThe thesis mainly investigated the reaction that magnesium powder mediated stereoselective olefination, silyetherization, and cyclization of carbonyl compounds with aryl or alkyl halide using the Lewis acid (TMSCl) in one-pot.This thesis includes four chapters.Chapter one: The development of modern organic synthesis by Magnesium This chapter summarized composition, structure and properties of Grignard reagents,then the recent mainly progress of modern organic synthesis by Magnesium, which is one of the most fundamental transformations in organic synthesis, Finally Grignard reagents and magnesium on the strengths and limitations were comprehensive review in organic synthesis.Chapter two: Mg-mediated three-component, one pot Synthesis of homoallyl silylethers.This chapter briefly reviewed research progress of TMSCl in organic synthesis, reaction conditions were optimized base on the influence of different reaction, under the control of magnesium and TMSCl halohyrocarbon and different aromatic aldehydes or ketones were reported, 18 kinds of Homoallyl Silylethers were synthesized, including dozens of new compounds, all products were characterized by IR, 1~H NMR, (13)~C NMR, MS and elemental analyses, This new method offers the possibility for the hydroxyl protection, the formation of new C-C, O-Si bonds and the synthesis of the natural active products with a high yield, short reaction time, do not use the advantages of the catalyst.Chapter three: Unexpected Barbier-type olefination of carbonyl compounds with alkyl halides in one-pot under solvent-free conditions.This chapter briefly reviewed the latest research progress of 1,2 - stilbene compounds in organic synthesis. from the environment-friendly point of view, firstly "a pot" TMSCl catalyzed under solvent-free conditions, unexpected Barbier-type olefination products was provided with alkyl halides and carbonyl compounds by magnesium promoted, which is a new green chemical synthesis of 1,2 - stilbene compounds. Synthesized the 28 kinds of 1 ,2 - stilbene compounds, including eleven new compounds. By melting point, IR, 1~H NMR, (13)~C NMR, MS, and elemental analysis of the structure of the product. This method is a new method to construct C=C bond, advantages of the present method is the excellent yields, shorter time, high stereoselective, and environmentally benign reaction conditions.Chapter four: Darzens condensation reaction of aromatic aldehydes withα-bromo ketones catalyzed by TMSCl.This chapter summarized the latest research progress of Darzens condensation reaction. A series of epoxide compounds catalyzed by TMSCl are synthesized by Darzens condensation reaction of aldehydes andα-Bromo Ketones in the presence of Mg and ethanol, The structure of the products are characterized by melting point, IR, 1~H NMR and (13)~C NMR. The reaction has the advantage of simple working-up procedure, mild reaction conditions, no pollution, excellent yields, and meets the requirements of green chemistry.