Synthesis Of Nitrogenous Heterocyclic Compounds Via Difunctionalization Of Alkenes

Heterocyclic compounds widely exists in nature, which are numerous, and have yet to a third of the organic compounds. Nitrogenous heterocyclic compounds are a class of important heterocyclic compounds, have been used as structural units of natural products, pharmaceuticals and agrochemicals due to their high biological activities. Furthermore, nitrogenous heterocyclic compounds are also key intermediates for synthesis of organic materials and fine chemical products, play an important role in our daily lives. Therefore, the preparation of nitrogenous heterocyclic compounds is one of the most active fields in organic chemistry.Oxindole and dihydroisoquinolineone are two nitrogenous heterocyclic compounds which are widely used in organic synthesis. Many studies have been reported for synthesis of the two heterocyclic compounds. On the basis of previous studies, we further developed new methods for synthesis of functionalized oxindoles and dihydroisoquinolineones via the direct difunctionalization of alkenes, including the following three aspects:1. Sulfonated oxindoles were synthesized when N-aryl acrylamide and sulfinic acid were used as starting materials, eosin Y as photocatalyst, tert-butyl hydroperoxide as oxidant. Water was employed as solvent, avoiding the use of organic solvents. Studies on the scopes of this reaction indicated that aliphatic sulfinic acids was also suitable substrates on the optimized condition.2. Alkylated oxindoles were synthesized via visible-light induced addition and cyclization reactions from N-aryl acrylamide and tetrahydrofuran. The reaction was achieved when eosin Y was used as photocatalyst, tert-butyl hydroperoxide as oxidant,4 ? molecular sieve as additive. This method selectively activated the C(sp~3)-H bond adjacent to a hetero atom, and constructed two C-C bonds in one step with high efficiency and atoms economy, avoiding the application of transition metal catalysts and related ligands.3. Direct synthesis of sulfonated dihydroisoquinolones from N-allylbenzamide and arylsulfinic acids via TBHP-promoted radical addition/cyclization cascade. This reaction used tert-butyl hydroperoxide as oxidant, aryl sulfinic acids as sulfonylation reagents, the mixture of water and acetonitrile as solvent. This method was easy to operate, mild, and well compatibile with functional groups.