Zhen Zhang

A novel visible-light-induced radical cascade spirocyclization of 1,7-enynes with diverse α-bromocarbonyl compounds is developed for the efficient construction of functionalized spirooxindole derivatives. This protocol features mild reaction conditions and simple operation, enabling the one-step assembly of complex spirocyclic skeletons with high diastereoselectivity. Scale-up synthesis and diversified product derivatizations further demonstrate the synthetic utility of this methodology. A series of control experiments confirm a radical-involved reaction pathway involving key 1,5-hydride shift and radical rearrangement processes.

A visible light-induced radical-cascade acylation/cyclization involving 1,7-dienes and acyl chlorides has been developed. This protocol presents a practical and environmentally benign method for the preparation of diverse acyl benzo[b]azepine derivatives in high yields. The gram-scale synthesis and late-stage modification show the applicability of the reaction. Further radical trapping experiments and luminescence quenching studies elucidate the reaction mechanism.

An Fe( iii )/NaBD ₄ -mediated regioselective deuteration/cyclization of 1,7-enynes and 1,7-dienes to construct deuterated dihydroquinolin-2(1 H )-ones and benzo[ b ]azepinones is presented.

A metal‐free cascade oxidative cyclization method has been developed for synthesizing functionalized benzo[b]azepin‐2‐ones from 1,7‐dienes using alcohols, ethers, or aryl aldehydes. The reaction generates α‐oxyalkyl or acyl radicals by direct C(sp³)H or C(sp²)H cleavage, avoiding photocatalysts and transition metals. This approach offers a mild strategy for the synthesis of benzo[b]azepine derivatives with high atom economy and efficiency. Mechanistic studies, including radical trapping and high‐resolution mass spectrometry analysis, confirm a radical‐mediated pathway involving cyclization and single‐electron transfer.

An oxidative cascade iodocyclization of 1,7- or 1,8-dienes has been realized under mild conditions. By employing I₂ as an iodine source, this protocol provides a concise and efficient approach to a great deal of biologically significant iodinated benzo[b]azepine and benzo[b]azocine derivatives in moderate to good yields. The gram-scale synthesis and further transformation of products render the approach practical and attractive. Radical trapping and deuterium-labeling experiments help to understand the mechanism.

A silyl radical-induced cascade silylation/cyclization of 1,7-dienes to construct valuable Si-containing benzo[b]azepin-2-ones is presented.

A novel radical cascade trifluoromethylthiolation/cyclization of dienes (N-alkyl-2-(1-phenylvinyl)aniline derivatives) with AgSCF₃ has been developed. This approach provides simple and efficient access to a wide range of SCF₃-containing medium-sized rings (7/8/9-membered heterocycles). Preliminary mechanistic studies suggest that the reaction is realized through a silver-assisted radical cascade cyclization process. The large-scale experiment and modification of the product reveal the promising utility of this protocol.

A novel visible-light-promoted selective sulfonylation and selenylation of dienes with selenosulfonates has been developed. This technology provides mild access to a wide range of sulfonyl benzo[b]azepinones and seleno-benzo[b]azepines. Preliminary mechanistic studies suggest that the sulfonylation involves a sulfonyl radical engaged cascade process, and the selenylation is accomplished through a sequential oxidation/electrophilic cyclization process. The large-scale operation and late-stage modification experiment reveal the promising utility of this protocol.

A cascade selenylation/cyclization of dienes with diselenides has been realized under visible-light irradiation or electrolysis conditions. Employing O₂ or electricity as a "green" oxidant, this protocol provides a green and efficient method for an array of biologically important seleno-benzo[b]azepine derivatives in moderate to good yields. The direct sunlight irradiation and gram-scale reaction render the approach practical and attractive.

A O₂N˙-triggered addition 7-endo cyclization to nitro-benzo[b]azepines is reported with good chemo- and regioselectivity. Large-scale operation and handy N-Ts and N-Cbz deprotection reveal the utility of this methodology.