The Study Of Organozinc Reagents With α-Halo Ketones And Research On Iron-catalyzed C-H Activation

This thesis includes two chapters:1. Organozinc reagent is an important class of organometallics in organic synthesis.Organozinc reagents have already represented many advantages，such as excellentfunctionality compatibility, high chemoselectivity, regioselectivity and stereoselectivityin organic synthetic chemistry because of their low reactivity. The reaction oforganozinc reagents with α-halo ketones has been attracted our attention, and carried out.The experiment of allyl bromozinc reagents and propargylzinc bromide with α-haloketones showed that the epoxides were efficiently obtained in high yields withoutadditive.2. With the emergence of the concepts of “green chemistry” and “atom economy”,the cross-coupling for C-X (C, O, N, S, etc.) bond formation via transitionmetal-catalyzed C-H activation is a challenging subject.(1) In this thesis, we have developed a highly efficient iron-catalyzed method foramidation of aldehydes in the presence of N-bromosuccinimide (NBS), and the methodis of simple, economical and practical advantages for synthesis of imides. To achievethe amidation, we have examined a variety of conditions including oxidants, iron saltsand solvents. After the optimization process, aldehyde and amide were carried out underour standard conditions:10mol%FeCl2as the catalyst,1.5equiv of NBS as the oxidant(relative to aldehydes) and CH3CN/CCl4(volume ratio1:5) as the solvent.(2) We have next explored the oxidative coupling of azoles with benzylic C(sp3)-Hbond to form C-C bond at the2-position of azoles catalyzed by iron．After theoptimization process, we establish the system:10mol%FeCl2as the catalyst,2.5equivof DDQ as the oxidant (relative to azoles) and chlorobezene as the solvent.The above two systems mainly involved the formation of C-N, and C-C bond, which are difficult to construct by the traditional methods and could be directly realizedwith high efficiency via oxidative dehydrogenative-coupling reaction. In the view of thesimplicity of the operation, short procedure, availability of the material and atomeconomical, the above procedures are very ideal methods for the concise and efficientsynthesis of the corresponding compounds．...