Study On The Ring - Trimerization Of Acetylene And α - Arylation Of 1,3 - Dicarbonyl Compounds

Aryne, which is a highly active organic reaction intermediate and provides an important method for the construction of carbon-carbon bonds, has been of particular interest due to its broad applications in the synthesis of natural products, alkaloids, drug intermediates and functional materials. Among them, Pd(0)-catalyzed cyclotrimerization of arynes provided an efficient synthetic method for the synthesis of triphenylenes, which is a kind of bowl liquid crystal materials. However, the reaction conditions need strict water-free and oxygen-free conditions. On the other hand, aryne has not been well used in á-arylation of carbonyl compounds, and its reactions with 1,3-dicarbonyl compounds mainly involved carbon-carbon σ–bond insertion reactions. Based on these backgrounds, this thesis mainly includes:1. Study on Au(I)-catalyzed cyclotrimerization of arynesA new method of Au(I)-catalyzed cyclotrimerization of arynes for the synthesis of triphenylenes was developed under mild conditions. By optimizing the reaction conditions, we obtained the optimal reaction conditions: o-trimethylsilyl triflate as benzyne precursors, 10 mol% of PPh3 Au Cl as the catalyst, Cs F as the fluoride ion, CH3 CN as the solvent, and the reaction was set at 60°C. Under the optimal reaction conditions, the cyclotrimerization of arynes led to the formation of a series of triphenylenes derivatives in 45%–88% yields. Further investigations showed that, Au(I)-catalyzed cyclotrimerization of arynes is also an efficient reaction to give triphenylenes in the air and a small amount of water. Compared with the results of previous studies, we developed the new method under the mildest conditions.2. Study on α-arylation of malonates with arynesA method of α-arylation of malonates with arynes was developed under mild conditions. By optimizing the reaction conditions, we obtained the optimal reaction conditions: o-trimethylsilyl triflate as benzyne precursors, excess malonates, Cs F as the fluoride ion, CH3 CN as the solvent, and the reaction was set at 60°C. Under the optimal reaction conditions, a-monoarylation of malonates with arynes led to the formation of a series of α-arylmalonates in 54%–88% yields. Further investigations showed that, the more efficient reactions of malonates with excess benzyne which mainly undergo a tandem arylation–insertion reaction pathway to give diarylmethane derivatives.