Electrochemical Synthesis Of Oxoindoline And γ-Lactam

Carbon-centered radicals are an important class of reactive species with translational potential in organic synthesis.When we considered to use electrochemical methods to generate carbon free radicals,there are many advantages of this newly synthesis way,such as no need for additional oxidant,avoiding harmful reaction by-products,which is more coincide with the concept of green chemistry.1,3-Dicarbonyl compounds are widely used molecular motifs for organic synthesis,and 1,3-dicarbonyl moieties can be oxidized and activated by cleavage of acidic C-H bonds.Because of the electron-withdrawing effect of the carbonyl group,the carbon radicals generated are relatively electron-deficient,and can react with the aromatic ring or double bond of the electron-rich to form a new carbon-carbon bond to realize the synthesis of a new organic molecular structure.This dissertation focuses on the electrochemical generation of Carbon-centered radicals from 1,3-dicarbonyl compounds and their applications in intramolecular dehydrogenative cyclization reaction and intermolecular annulation reaction.Firstly,the intramolecular reaction properties of malonate amides including 1,3-dicarbonyl structure were explored.C3-alkyl oxindoles were synthesized through cross-dehydragenative coupling of C(sp3)-H and C(sp2)-H bonds by electrochemical method using cost-effective and easily available ferrocene as a catalyst with broad substrate scope.And only by-product is hydrogen,which has the characteristics of green and high efficiency.At the same time,it can achieve a degram preparation in high yield easily.(?)Scheme 1 Electrosynthesis of 3-alkyloxindoles Secondly,the intermolecular reaction properties of malonate compounds containing 1,3-dicarbonyl structure were studied.Herein,we report a new ferrocene-catalyzed tandem annulation of three components through electrosynthesis,namely alkenes,malonate esters and primary amines,to synthesize a-fluoro or a-alkyl substituted y-lactam compounds.The multicomponent reaction enables the formation of three new chemical bonds,one C-C bond and two C-N bonds in one pot.This method obviates the need for oxidizing reagents and pre-functionalization,providing an efficient and sustainable access to y-lactams from simple and available starting materials.(?)Scheme 2 Electrosynthesis of y-lactam...