A novel strategy for the synthesis of imidazo-fused polycyclic compounds under mild, base-free, and silver-free conditions by a rhodium­(III)-catalyzed C–H annulation of alkenyl or arylimidazoles and (hetero)­cyclic 1,3-dicarbonyl compounds is reported here. Such a step-economic protocol features the selective cleavage of two different C–H bonds in one step, featuring easy operation, readily available starting materials, gram-scale synthesis, broad functional group tolerance, and no requirement to presynthesize carbene precursors. Notably, the synthetic potential is showcased by the structural modification of drug and the highly step-economic synthesis of Janus kinase inhibitor in only three steps with a satisfactory 26% total yield (previous method: in nine steps with 0.6% yield).

Wood processing waste, poplar wood shavings, were used for fiberboard production, and the pretreatment conditions using cellulase were studied using response surface methodology (RSM). After single factors optimization, central level of temperature, dosage, and liquid/solid ratio (LSR) of cellulase pretreatment conditions were obtained. Further optimization to study the influence of the factors was carried out using Box-Behnken design of experiments. A second-order polynomial equation was obtained, and the low p-value (<0.007) implied that the model was highly significant by analysis of variance (ANOVA). The optimized cellulase pretreatment conditions for maximum bending strength (BS) of the fiberboard were determined by ridge analysis as 44.4 °C of temperature, 1.23 U/g of dosage, 4.2 of LSR, and 5 h of pretreatment time. Under the optimized conditions, the BS of the fiberboard reached 25.12 ± 0.35 MPa by validation experiment, which was twice that of the fiberboard without pretreatment. Thus, the cellulase pretreatment should be a good choice to produce high-strength binderless fiberboard.