Reactions Of Aryl Isocyanates With Organozinc Halide Eagents

Isocyanates are highly unsaturated groups. They have different electricphiliccenter and nucleophilic center. Because of high reactivity, isocyanates can participatein many organic chemical reactions, and they can also be widely used in pesticide,medicine, organic synthesis and polymer industry. In addition, as a kind oforganometallic reagents, organozinc reagents have very good capacity of carryingfunctional groups, due to their low reactivities, higher chemoselectivity andstereoselectivity of chemical reactions, they are ideal reagents to build multifunctionalcomplex compounds. Herein, the reactions of aryl isocyanates with organozinc halidereagents were firstly investigated.The thesis mainly consists of the following three parts:Chapter one: The research progress of isocyanates in organic synthesisIn this chapter, we summarized the development of isocyanates, main preparationmethods of isocyanates, and the research progress of isocyanates in various organicsynthesis reactions.Chapter two: Reactions of aryl isocyanates with alkylzinc halideIn this chapter, we provided a new synthetic method for N-substitutedcarbamates, and discussed the influence of reaction conditions on the reaction afterdoing researches on reactions of alkylzinc halide with aryl isocyanates. This is aconvenient way to prepare N-substituted carbamates because of catalyst freeconditions, low cost, simple operations, mild conditions, and high yields.Chapter three: Reactions of aryl isocyanates with allylzinc bromide and propargylzinc bromideIn this chapter, we provided a new synthetic method of N-substituted amides, anddiscussed the influence of reaction conditions on the reaction after further studies onthe reactions of aryl isocyanates with allylzinc bromide and propargyl zinc bromide.This is a new effective way to prepare N-substituted amides because of catalyst freeconditions, low cost, simple operations, short reaction time, mild conditions, and highyields. In addition, we tried to deduce reaction mechanisms and discuss the problemin preparing organozinc halide reagents.