Studies On Transition Metal Catalyzed Decarboxylation Reaction And Phase-Transfer-Catalyzed (PTC) Cyclization Reaction

Chapter 1.The development and application of decarboxylation reactions in organic synthesis were summarized in detail, which includes decarboxylative protonation reaction, decarboxylative homocoupling reaction, decarboxylative coupling reaction, decarboxylative-C/H activation reaction, decarboxylative alkylation reaction, decarboxylative cyclization and other types of decarboxylation reaction.Chapter 2.This work is the first example of decarboxylative coupling to construct C-P bond(Csp3-P, Csp2-P and Csp-P), which is highly important in biologically active products. Compared with traditional methods, the reaction affords simple operation, easily availability, mild reaction condition, the best regioselective and chemoselective, good functional group tolerance. The reaction is applied to synthesize various phosphorus ligand and a possible mechansim is proposed. The structure was definitively secured by an X-ray crystal structure analysis.Chapter 3.A novel Pd/C-catalyzed reaction for the synthesis of benzo[b]furan derivatives including terminal olefins or allenyl group from propargylic compounds with high regioselectivity was described in detail. This reaction was easily conducted under ambient conditions of air and lower catalyst loading was used in this process. In particular, there have been few reports on benzo[b]furans syntheses from alkynylbenzene derivations via carbon-carbon bond (C-C) cyclization.Chapter 4.A variety of substituted benzo[b]furans are readily prepared in good to excellent yields under the mild reaction conditions with PTC (Phase-transfer catalysis) for the first time. This methodology accommodates simple experimental operations, inexpensive and environmentally benign catalyst, metal catalyst-free condition, facile reagents and possibility to conduct large-scale preparations. Furthermore, the indane derivatives were also smoothly proceeded in our system.Chapter 5.Phase-transfer-catalyzed intramolecular cyclization reaction of forming benzo[b]furan and 3-methyleneisoindoline-1-one derivatives has been developed. The cyclization reaction of propargylic carbonates was also described under metal-free condition and the reaction was reported by Pd and Ni before. The catalysts are cheap and environmentally friendly and the substrates are readily available and the procedure is simple, rapid, and general.Chapter 6.A variety of substituted 4H-pyrans are readily prepared in moderate to good yields under the mild reaction conditions by nucleophilic addition to electron-deficient 1,3-conjugated enynes with PTC (Phase-transfer catalysis). The reaction is mild and easily conducted and 100% atom-economic.