N-heterocyclic nitrenium-catalyzed photosynthesis of 3,3-disubstituted oxindoles from α-chloroanilides.

The radical cascade reaction of α-halogenated anilides represents an efficient approach for synthesizing 3,3-oxindoles. However, most methods have focused on α-bromoanilides, with limited utilization of the more stable and readily available α-chloroanilides. In addition, the transition-metal-free preparation of 3,3-oxindoles has been far less explored.

Small change, big difference: A promising praziquantel derivative designated P96 with broad-spectrum antischistosomal activity for chemotherapy of schistosomiasis japonica.

Background: Praziquantel (PZQ) has been the first line antischistosomal drug for all species of Schistosoma, and the only available drug for schistosomiasis japonica, without any alternative drugs since the 1980s. However, PZQ cannot prevent reinfection, and cannot cure schistosomiasis thoroughly because of its poor activity against juvenile schistosomes. In addition, reliance on a single drug is extremely dangerous, the development and spread of resistance to PZQ is becoming a great concern.

Photoinduced halogen-bonding enabled synthesis of oxindoles and isoindolinones from aryl iodides.

We report the use of halogen bonding (XB) for the generation of aryl radicals from aryl halides under blue light irradiation and applied it in radical generation/1,5-hydrogen-atom transfer/radical cyclization cascade reactions for the synthesis of oxindoles and isoindolinones. On the basis of experimental studies, we propose that DBU can serve as a suitable XB acceptor with aryl halides for the formation of a photoactive electron donor and acceptor complex.

Catalytic charge transfer complex enabled difluoromethylation of enamides with difluoromethyltriphenylphosphonium bromide.

A catalytic charge transfer complex strategy that enabled difluoromethylation and ethoxycarbonylmonofluoromethylation of enamides with phosphonium bromine salts has been reported. This strategy also provides a convenient approach for the synthesis of functionalized oxindoles and 1,1-diphenylethylenes with easily available phosphonium bromine salts and a catalytic amount of iodine anion.

N-Heterocyclic carbene-catalyzed oxidative [3 + 2] annulation of dioxindoles and enals: cross coupling of homoenolate and enolate.

The N-heterocyclic carbene-catalyzed oxidative [3 + 2] annulation of dioxindole and enals was developed, giving the corresponding spirocyclic oxindole-γ-lactones in good yields with high to excellent diastereo- and enantioselectivities. The challenging aliphatic enals worked effectively using this strategy. The oxidative cross coupling of homoenolate and enolate single electron transfer was proposed as the key step for the reaction.

N-Heterocyclic carbene-catalyzed [3 + 2] annulation of bromoenals with 3-aminooxindoles: highly enantioselective synthesis of spirocyclic oxindolo-γ-lactams.

The chiral N-heterocyclic carbene-catalyzed [3 + 2] annulation of α-bromoenals and 3-aminooxindoles was developed, giving the corresponding spirocyclic oxindolo-γ-lactams in good yields with high diastereoselectivities and enantioselectivities.

[Research progress of small peptidomimetics].

The study of peptide drugs has been an important direction in research and development of new drugs. However, lots of natural macromolecular peptides are limited in clinical use by their metabolic instability and low bioavailability. In recent years, the active small peptidomimetics open up a new hotspot of peptide drug development with the characteristics of low molecular weight, high bioactivity and structural modification.

Enantioselective N-heterocyclic carbene-catalyzed synthesis of indenopyrones.

The chiral N-heterocyclic carbene-catalyzed [4 + 2] cyclization of α-chloroaldehydes and arylidene indanediones was developed, giving the corresponding indenopyrones in good yields with high diastereoselectivities and enantioselectivities.

Enantioselective N-heterocyclic carbene-catalyzed synthesis of trifluoromethyldihydropyridinones.

The enantioselective N-heterocyclic carbene-catalyzed [4 + 2] cyclocondensation of α-chloroaldehydes and trifluoromethyl N-Boc azadienes was developed, giving the corresponding 3,4-disubstituted-6-trifluoromethyldihydropyridin-2(1H)-ones in good yields with exclusive cis-selectivities and excellent enantioselectivities.