| Organozincs are an important class of organometallics for organic synthesis and organometallic synthesis. A variety of functional groups may be tolerated in these organometallic reagents because of their moderate reactivity. Most importantly, recent investigation found that these reagents, under the presence of a Lewis acid and by the catalysis of transition metal complexes or salts, could react with a range of organic electrophiles. Thus a large range of functional groups can be directly introduced into target molecules and possibly a shorter synthetic route would be realized by avoiding the use of protection-deprotection steps as well as functional group interconversions.Diorganozincs have found extensive application in asymmetric synthesis, since they add to aldehydes in the presence of a chiral catalyst with high enantioselectivity. However, the reactivity of organic zinc halides are lower than diorganozincs and in most cases, they react with aldehydes only after these reagents be transmetalated to corresponding organometallic reagents by CuCN or other transition metallic salts. In 2001, our lab first reported a novel dialkylation reaction of alkyl zinc iodides with aromatic aldehydes. In the presence of Lewis acid Me3SiCl, under the catalysis of Ni(acac)2 and a tertiary amine, these reactions proceeded smoothly and dialkylation products instead of secondary alcohols were obtained.The destination of this thesis is to study the addition reaction of organozinc halides with aromatic aldehydes under the catalysis of transition metal complexes such as nickel and cobalt based on previous experiments. The reaction conditions of functionalized alkyl zinc iodides with aromatic aldehydes selected and further a reaction intermediate silyl ether was isolated by which a more perfect mechanism was proposed. In this thesis, 67 compounds in all were synthesized, among them, 19 products are new compounds.This thesis includes three chapters.Chapter One: The Development of Polyfunctional Organozinc Halides in Organic Synthesis.In this section, a brief introduction of the development of polyfunctional organozinc halides in organic synthesis was given, and then reviewed in detail on the preparation and reaction of polyfunctional organic zinc halides, which were of the most importance both3on application and theory.Chapter Two: Ni(acac)2 Catalyzed Dialkylation Reaction of Functionalized Organozincs with Aromatic Aldehydes.Under the catalysis of Ni(acac)2/tertiary amine and in the presence of Lewis acid Me3SiCl, functionalized organic zinc iodides reacted with aromatic aldehydes giving dialkyiation products in moderate to high yields. The best ratio of reactants was selected and intermediate silyl ether was isolated, functional groups such as chloro, bromo, and ester were introduced directly into products. 19 dialkyiation compounds were synthesized by this procedure. Among them, 11 compounds are new products. This methodology was shown to be very efficient in the synthesis of the long chain aromatic hydrocarbons.Chapter Three: The Olefination Reaction of Organic Zinc Halides with Aromatic Aldehydes.In the first part of this chapter, an olefination reaction of functionalized alkyl zinc iodides with aromatic aldehydes was first reported. When the ratio of alkyl zinc iodides to aromatic aldehydes was changed to 1:1, a vinylation reaction occurred and the products were -alkyl styrenes instead of secondary alcohols or dialkylmethylbenzenes. This novel reaction indicates that these reactions proceed with a different mechanism to that of copper mediated. Hitherto, we have not found any of reports on the reaction of organozincs with aromatic aldehydes, which directly lead to -alkyl styrenes. These reactions proceeded with high chemselectivity and stereoselectivity. All of the functional groups in organozinc reagents or aldehydes were directly introduced into the corresponding products without further protection and the products were found to be pure (E) olefins. 17 alkyl styrenes were synthesized using t...
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