Synthesis Of 3-methyleneisoindolinone And Trisindolylmethanes Via Transition Metal Catalyzed Carbonylation

The advantages of carbonylations are(i)it is the promising methodology in the synthesis of carbonyl-containing chemicals,which increases the carbon number at the same time,and(ii)carbon monoxide(CO)can be used as an inexpensive and readily available Cl source,which is also in agreement with the green chemistry principles.3-methyleneisoindolin-l-one and tris(indolyl)methanes derivatives are valuable commodity chemicals and highly reactive intermediates.However,the conventional methods for the synthesis of these compounds generally require multistep procedures under harsh reaction conditions.Thus,the development of simple and economic methods for the synthesis 3-methyleneisoindolin-l-one or tris(indolyl)methanes derivatives is highly desirable.In this dissertation,we report the transition-metal-catalyzed carbonylation using carbon monoxide as building block for the synthesis of 3-methyleneisoindolin-l-one or tris(indolyl)methanes derivatives.Firstly,an efficient synthesis of 3-methyleneisoindolin-1-ones from(E)-1-(1-(2-iodophenyl)ethylidene)-2-phenylhydrazines,through palladium-catalyzed intramolecular C-I aminocarbonylation has been developed.The reaction carried out under atmospheric pressure of CO,provides diversified 3-methyleneisoindolin-l-ones in reasonable to good yields from(E)-1-(1-(2-iodophenyl)ethylidene)-2-phenylhydrazines,which are readily derived from phenylhydrazine and 1-(2-iodophenyl)ethanone.Compared with existing approaches to 3-methyleneisoindolin-l-ones,the current strategy features atom-economy and step-efficiency.Secondly,an efficient and practical synthesis of trisindolylmethanes has been developed via rhodium-catalyzed C-H bond carbonylation and subsequent bisarylation of indolyl aldehydes.[RhCp*Cl2]2 as catalyst,AgOAc as oxidant and AcOH/DMSO(1:3)as solvent gave the best results under 1 atm pressure of CO.The new method features atmospheric pressure of CO,good functional group tolerance,reasonable to good yields.