Photoinduced copper-catalyzed alkoxyl radical-triggered ring-expansion/aminocarbonylation cascade

A photoinduced copper-catalyzed alkoxyl triggered C-C bond cleavage/aminocarbonylation cascade is presented.Through adjusting the structure of alkoxyl radical precursors,functionalized lactones and ketoamides were synthesized with good yields and excellent functional group tolerance under redox-neutral conditions.Notably,this protocol enables the integration of lactone fragments with many amine drugs and drug fragments.

Lewis base catalyzed ring-expansion of isatin with 2,2,2-trifluorodiazoethane(CF3CHN2):An efficient route to3-hydroxy-4-(trifluoromethyl)quinolinones

A Lewis base catalyzed ring expansion of isatin with 2,2,2-trifluorodiazoethane(CF3 CHN2)is developed.It is characterized that the merge of tetramethylethylenediamine and CF3 CHN2 generates reactive triazene intermediates,which construct substituted 3-hydroxy-4-(trifluoromethyl)quinolinones with high efficiency.Synthetic application of the procedure is broadened by 3-trifluormethylpyrazole fused3-hydroxy-4-(trifluoromethyl)quinolinone synthesis.

Pictet-spengler/transamination cascade reaction of indoles for modular synthesis of marinoquinoline analogues

The Pictet-Spengler/transamination cascade reaction enables modular synthesis of marinoquinoline analoguesthrough three-component indole ring-expansion/cyclization in the manner of novel N1–C2 cleavage of indoles.This metal-free protocol exhibits very broad functional group tolerance with up to quantitative yields. Preliminarystudies on the antitumor activity of the resultant marinoquinoline analogues reveal that the indolyl-attachedpyrrolo[2,3-c]quinoline product (5d) shows great potential (IC50 of 0.32 μg/mL to HeLa cells) as a promisinganticancer agent in clinic.

Topological effects of macrocyclic polymers:from precise synthesis to biomedical applications

Polymer chain architectures play a crucial role in the physical properties of polymers and this unique phenomenon has been recognized as the topological effects.As one of the most representative architectures,macrocyclic polymers characterized by the endless topology have received extensive attention due to their distinct physical properties as compared to the linear counterparts.To understand these differences and unravel the underlying mechanisms,there is a long pursuit to efficiently fabricate macrocyclic polymers.To date,both ring-closing and ring-expansion strategies have been developed,which drastically elevates the accessibility of macrocyclic polymers.The improved availability of macrocyclic polymers enables the further investigation of the biomedical applications and the preliminary results suggest that macrocyclic polymers outperform their linear analogs in terms of improving gene delivery efficiency,elevating blood circulation time,and enhancing colloidal stability of nanoparticles.