Synthesis Of Carbazolone Derivatives Via Benzyne Annulation And Diels-alder Reaction Involving γ-Arylallenylcarboxyamides

Benzyne is one of the important organic synthetic intermediates, and is high reactivity for its specific structure. So, benzyne can be used as a reagent for the synthesis of a variety of aromatic heterocyclic compounds efficiently. For the past few years, considerable interest had been focus to chemical of benzyne in organic synthesis, and the rapid development of the chemistry of benzyne was promoted.There are many methods of using benzynes for the synthesis of heterocyclic, and this research mainly focus on that benzynes react with nitrogen-containing compounds to synthetic nitrogen heterocycles. Our research aims to expand the applicable scope of using benzynes for the synthesis, and provide a new method of these nitrogen heterocycles. In this paper, the research is mainly divided into two parts:1. Amino cyclohexadienones have both of amino and Michael acceptor simultaneously. We hope that benzynes can be attacked by nitrogen atom and then react with cyclohexadiene for Michael addition, thereby get carbazolone derivatives. However, we do not get the desired product, but get the biphenyl derivatives.2.Benzynes reacting with γ-arylallenylcarboxyamides, are different from allenoic acids reacting with benzynes and getting chromone derivatives which reported by Ma. The amides do not take part in this reaction unexpectedly due to its poor reactivity. Instead, benzynes react with γ-arylallenylcarboxyamides in a Diels-Alder cycloaddtion fashion, leading to phenanthrene derivatives which have an amides structure. This acid vs amide contrast is another example in benzyne chemistry that isoelectronic atom replacement may lead to different reactivity and products. The result provides a new matter for chemistry of benzyne and also provides a new method for the synthesis of phenanthrene derivatives.