Studies On The Reaction Methodologies Of 3-Diazoindolin-2-imines

As important class of reactive species and useful synthetic intermediates,both diazo compounds and diazonium salts are widely used for the synthesis of organic molecules.In this thesis,the preparation and properties of the diazo compounds and diazonium salts are reviewed.Based on 3-diazoindolin-2-imines,a series of reaction types have been demonstrated,such as metal free reaction,photoreaction,metal-catalyzed reaction and so on.The details are summarized as following:1)K2CO3-promoted coupling reactions between 3-diazoindolin-2-imines and carbon nuclepophilesPotassium carbonate-promoted coupling reactions between 3-diazoindolin-2-imines and carbon nucleophiles were tested.By respectively applying 2-naphthalenols and 2-arylacetates as nucleophile,3-azoindoles and 3-hydrazonoindolin-2-imines were obtained in excellent yields.Moreover,3-azoindol-2-amines could be used as NNO pincer ligands for boron and resulted in the formation of hexacycleborofluorides with their solid absorptions around 660 nm.It implies that this type of compounds might be used as near-IR absorbant materials in the future.2)Light-promoted rearrangement of 3-diazoindolin-2-imines3-Diazoindolin-2-imines undergoes rearrangement under the irradiation of light.The oxygen on the sulfonyl of 3-diazoindolin-2-imines could migrate to 3-positon of indole and forms 2-sulfenylimido-3-indolones.On the basis of the structual analysis of the by-product,the possible reaction mechanism was proposed.3)Rh-catalyzed reactions between 3-diazoindolin-2-imines and 2H-azirinesA rhodium catalyzed reaction between 3-diazoindolin-2-imines and 2H-azirines,followed by treatment with base,produces 5H-pyrazino[2,3-b]indoles in excellent yields.A number of functional groups tolerate the reaction conditions and the synthesized 5H-pyrazino[2,3-b]indoles present strong photoluminecence in solutions,in powders,and in films.We designed and synthesized a series of new photoluminescent molecules containing 5H-pyrazino[2,3-b]indole backbone,and these compounds might be applied as hole transport materials in optoelectronics.4)Pd-Catalyzed coupling reactions between 3-diazoindolin-2-imines and arylboronic acids2-Amino-3-arylindoles were conveniently prepared from 3-diazoindolin-2-imines and arylboronic acids through palladium carbene intermediates in moderate to excellent yields.The synthesized 2-amino-3-arylindoles could be fluorinated with NFSI to afford 3-aryl-3-fluoroindolin-2-imines.A possible reaction mechanism was proposed and the palladium carbene was postulated as the key intermediate during the reaction.