Studies On Copper-Catalyzed Synthesis Of Indolo[2,3-c]pyrane-1-ones And Thieno[2,3-c]pyrane-7-ones

Indolo[2,3-c]pyrane-1-ones and thieno[2,3-c]prane-7-ones are ones of the important heterocycles,which exist extensively in many natural products and biologically active compounds.Especially,they have shown anti-cancer potential and inhibiting tumor cell growth based on recent reports.There are several methodologies for the synthesis of indolo[2,3-c]pyrane-1-ones and thieno[2,3-c]pyrane-7-ones.For example,most reported cases used expensive transition-metal complexes,such as palladium,rhodium,ruthenium,and gold as the catalyst.The examples,which use inexpensive transition-metal complexes of copper and iron,suffered from the need of stoichiometric amounts of metals.Other examples did not use transition-metal complexes,however,the reactions have to prepare the functional substrates by mutil-steps or activate the inert substrates by harsh reaction conditions,such as high temperature or microwaves.The study of these compounds' properties is confined by the disadvantages as mentioned above.As a result,the development of an efficient synthetic method for the synthesis of indolo[2,3-c]pyrane-1-ones and thieno[2,3-c]pyrane-7-ones has attracted considerable attention.In this thesis,we used a copper salt,which is low cost and low toxicity,as a catalyst to develop an effective method for the synthesis of indolo[2,3-c]pyrane-1-ones and thieno[2,3-c]pyrane-7-ones from easily available heteroaromatic ?-halo-?,?-unsaturated carboxylic acids with alkynes.We chose 1-methyl-3-iodo-indole-2-carboxylic acid and dimethyl acetylenedicarboxylate as the model starting materials to test the reaction conditions,such as copper salts,bases,solvents,reaction temperature and reaction time.Futhermore,the tolerance of different functional groups was tested under the optimal condition,and a series of indolo[2,3-c]pyrane-1-ones and thieno[2,3-c]pyrane-7-ones were obtained in moderate to good yields.This thesis provides a simple and efficient strategy for the synthesis of indolo[2,3-c]pyrane-1-ones and thieno[2,3-c]pyrane-7-ones,and further benefits the research of these compounds' properties.