Light-Induced Generation and Cycloaddition Reactions of Benzyne: Synthesis of Naphthoxindoles E and Annulated Indolizines.

By virtue of their high electrophilic nature, benzynes serve as reactive dienophiles in numerous cycloaddition reactions. However, in situ generation of benzyne involves either base-mediated thermal reactions, low-temperature conditions, or metal-catalyzed reactions of substituted arenes. This limits the applicability of benzynes as suitable dipolarophiles in cycloaddition reactions.

Blue LED Induced Three Component Reactions for the Generation of 4,6-Dioxo-hexahydro-1H-furo[3, 4-c] pyrrole: Their Evaluation as Anticancer Agents through PARP-1 Inhibition.

Herein we report a catalyst, metal and additive free generation of carbonyl ylides by blue LED irradiation of aryl diazoacetates in presence of aldehydes. The resulting ylides underwent [3+2] cycloaddition with substituted maleimides present in the reaction mixture to afford 4, 6-dioxo-hexahydro-1H-furo[3, 4-c] pyrrole in excellent yields. Fifty compounds were synthesized based on this scaffold.

Cu(II)-Catalyzed Multicomponent Reaction of Pyridine Derivatives/Isoquinolines with Iodonium Ylide and 1,4-Quinones Using Mechanochemistry.

An efficient copper-catalyzed solvent-free multicomponent reaction for pyridine derivatives, iodonium ylides, and 1,4-quinones is developed a room-temperature ball milling technique. The reported protocol provides a sustainable synthesis of isoindolo[2,1-a]pyridine/isoquinoline class of molecules in good to excellent yield in a mixer mill (RETSCH MM400) engaging the commercially available copper acetate (Cu(OAc)) as a catalyst without the use of organic solvents. It tolerates a myriad of electron-rich and electron-deficient functionalities on the pyridine moiety.