Scheme 3. Substrate scope for quinoxalines. Reaction conditions: 1 (0.2 mmol, 1.0 equiv.), 4 a (0.3 mmol, 1.5 equiv.), NaOH (0.3 mmol, 1.5 equiv.) and I (0.002 mmol, 1.0 mol %) in DMA (4.0 mL) was irradiated by a blue LED strip for 24 h at 50 8C. Isolated yields are shown.Scheme 4. Six-membered ring-fused substrates.Scheme 5. Proposed mechanism.

Visible-light photoredox catalysis has been successfully used in the functionalization of inert C-H bonds including C(sp )-H bonds of arenes and C(sp )-H bonds of aliphatic compounds over the past decade. These transformations are typically promoted by the process of single-electron-transfer (SET) between substrates and photo-excited photocatalyst upon visible light irradiation (household bulbs or LEDs). Compared with other synthetic strategies, such as the transition-metal catalysis and traditional radical reactions, visible-light photoredox approach has distinct advantages in terms of operational simplicity and practicability. Versatile direct functionalization of inert C(sp )-H and C(sp )-H bonds including alkylation, trifluoromethylation, arylation and amidation, has been achieved using this practical strategy.

Ap ractical and efficient method hasb een developed for the preparation of polysubstituted furans by using av isible-light-promoted photoredox approach. The one-pot synthesis involves ar adical cyclization/deprotection/aromatization reactions equence that proceeds smoothly under mild conditions, which makes this transformation ap owerful tool for the synthesis of av ariety of highly substitutedf urans.

Synthesis of Fused Quinoline and Quinoxaline Derivatives Enabled by Domino Radical Triple Bond Insertions. -The visible light mediated domino radical isocyanide/alkyne insertion reaction gives access to a wide range of quinolines, quinoxalines, and heterocycles (XV). In some cases, the rearrangement products (IV) are also formed. -(SUN, X.; LI, J.; NI, Y.; REN, D.; HU, Z.; YU*, S.; Asian J. Org. Chem. 3 (2014) 12, 1317-1325, http://dx.