Study On The Environmentally Friendly Reactions Of Alkyl Halides With β-nitroalkenes And Carboxylic Acid Derivatives Mediated By Magnesium Powder

In recent years, with the rapidly emerging and development of green chemistry, environmentally friendly-economics have become an important impetus of technology innovator, and make green organic synthesis face serious challenge. Developing more benign synthetic procedures in chemical synthesis is important in moving towards sustainable technologies. In reducing the amount of waste, energy usage, and the use of volatile, toxic and flammable solvents, several approaches are available including avoiding the use of organic solvents for the reaction media. Replacement media include non-volatile and recyclable ionic liquids, H2O, supercritical CO2, polyethylene and polypropylene glycol. An alternative approach avoids the use of a reaction medium as the so-called'solvent free'or'solventless'reaction. Solvent-free organic synthesize technology, due to its ability to reduce the pollution from headstream, and efficiently utilizing the source, now has become the hotspot in the organic synthesize studying. Also it is an important part in the green chemistry. The Metal-promoted reaction have several advantages such as the quick speed of reaction, chemical selectivity, region selectivity and solid selectivity, so it is a kind of synthesis reagents with considerable applicable value and applicable prospect.Conjugate addition of organometallic reagents to powerful Michael acceptors has a vital function in carbon-carbon bonds formation. Nitrostyrenes is a kind of remarkable acceptors for conjugate addition. Nitrostyrenes due to strongly electron-withdrawing group can be easily transformed into a variety of valuable functionalities such as amines, ketoximes, hydroxylamines and nitroalkanes. Therefore, the subject of conjugation of nitrostyrenes has received a great of attention in recent years. There have been many reports on conjugate addition of nitrostyrenes mediated by organometallics. However, most of them were not satisfactory due to undesirable side reactions and poor conversion. Moreover, the organometallic reagents needed to be prepared beforehand and the process was rigorous.From the view of environmentally friendly, this thesis achieved the conjugate addition of allyl bromide and benzyl bromine with nitrostyrenes mediated by magnesium powder in one pot under the solvent- free conditions. At the same time, bisallylation of carboxylic acid derivatives with allylzinc Bromide was investigated under solvent-free conditions and no-catalyst condition. This thesis includes three chapters.Chapter one: Recent Development of Green Reaction Mediated by Metal MagnesiumIn this section, magnesium-mediated organic reaction of addition, reduction, elimination and coupling were reviewed. In particular, magnesium mediated addition and reduction reaction were summarized in detail. At the same time, the reaction of Grignard reagent and solvent-free reaction were introduced briefly.Chapter two: Environmentally Friendly One-Pot Conjugate Addition ofβ-Nitroalkenes Mediated by Magnesium PowderThis chapter mainly investigated 1,4- conjugate addition of nitrostyrenes mediated by magnesium powder in one pot under the solvent- free conditions at 0 oC. Compared with previously reported methods, advantages of the present method are the excellent yields, short reaction time, operational simplicity and good selectivity. More importantly, the method accorded with green chemistry theory and tried to avoid the reagent pollution from the headstream, which provided a new method of green organic synthesis for protecting environment.Chapter three: Bisallylation of Carboxylic Acid Derivatives Mediated by Magnesium Powder Under Solvent-free and No-catalyst ConditionIn this section, we studied bisallylation of carboxylic acid derivatives mediated by magnesium powder under solvent-free and no-catalyst conditions. A rapid, convenient, and efficient approach of synthesizing compounds of bisallyl alkyl carbinol was provideed. Compared with methods reported by literature, advantages of the present method are the rapid reaction rate, excellent yields, no-pollution and environmentally friendly.