A copper-catalyzed annulation of O-acyl oximes with cyclic 1,3-diones has been developed for the concise synthesis of 7,8-dihydroindolizin-5(6H)-ones and cyclohexanone-fused furans through the substituent-controlled selective radical coupling process. 2-Alkyl cyclic 1,3-diones undergo C–C radical coupling, while 2-unsubstituted cyclic 1,3-diones undergo C–O radical coupling.

A copper-catalyzed annulation of α,β-unsaturated O-acyl ketoximes with isoquinolinium N-ylides has been developed for the concise synthesis of stable N–H imines with a benzo­[7,8]­indolizine core. When β-(2-bromoaryl)-α,β-unsaturated O-acyl ketoximes are used as the starting materials, a cascade cyclization occurs to afford the benzo­[7,8]­indolizino­[1,2-c]­quinolines.

A novel P/N/Si-containing flame retardant (marked as DASO) was synthesized through an Atherton–Todd reaction between 9,10-dihydro-9-oxa-10-phospha-phenanthrene-10-oxide and aminophenyl silicone oil, and further used for reducing fire hazards of polycarbonate (PC). The chemical structure of DASO was verified via FTIR, 1H, and 31P NMR. Upon the incorporation of 2 wt% DASO, the FRPC composite achieved a high limiting oxygen index (LOI) of 32.2% and a desired UL-94 V-0 rating. In this case, the peak heat release rate (PHRR) and total smoke production (TSP) were reduced by 26% and 44% as compared with the pure PC, respectively. The improved fire safety contributed to the flame retardant roles of DASO in both the condensed phase and gas phase. The presence of DASO promoted the formation of dense and highly graphited char layer in the condensed phase, and released non-combustible gases and phosphorus-containing radicals in the gas phase. Furthermore, the FRPC composites displayed comparable elongation at break but a slightly reduced tensile and impact strength.

Silicone diphenylsulfonate (SDPSF) was synthesized via nucleophilic substitution reaction between dihydroxyalkyl‐terminated silicone oil and benzene sulfonyl chloride, and its chemical structure was confirmed by Fourier transform infrared (FTIR) and 1H NMR. The effect of SDPSF on the flame retardancy, thermal stability, combustion behavior, and mechanical properties of PC/SDPSF blends were investigated. The PC/2 wt% SDPSF blend achieved the UL‐94 (3 mm) V‐0 rating and limiting oxygen index value of 30.3% together with the lowest values of the total heat release (32.2 MJ/M2), peak heat release rate (239.5 kW/M2), CO production (0.48 kg/kg), and fire growth index (1.09 kW/s·m2). It demonstrated that the SDPSF improved evidently the flame retardancy and fire safety of the polycarbonate (PC) matrix. The blend also gave a slightly reduced tensile strength (60.0 MPa) and notched impact strength (57.0 kJ/m2). The TG‐FTIR spectra of the pyrolysis gases demonstrated that the SDPSF promoted the decomposition of PC matrix on advance to release much more nonflammable gases in the early combustion process, meanwhile, the analysis of the char residues confirmed that the SDPSF facilitated the formation of compact and continuous layers with higher graphitization degree to isolate the transfer of heat and combustible volatiles.

A coppper-catalyzed [3+2] annulation of O-acyl ketoximes with 2-aryl malonates for the concise synthesis of 3-aryl-4-pyrrolin-2-ones has been developed. The advantage of this method lies in the use of O-acyl...