Palladium And Chiral Secondary Amine-Catalyzed C-C、C-S Bond Forming Reactions And Their Applications

Sulfoxide compounds mainly have a broad spectrum of biological activity and have a wide range of application in herbicides, fungicides, anticancer drugs and other aspects. In addition, the nitrogen-containing heterocyclic compounds have low toxicity, high efficacy advantages in the synthesis of pesticides and are also highly favored. Therefore, the development of methods in efficient and green synthesis of sulfoxides and heterocyclic compounds containing nitrogen have a positive significance in preparation of the new and innovative pesticides and their applications.Palladium-catalyzed cross-coupling reactions play an important role in organic chemistry, especially in highly efficient synthesis of C-C and C-S bond backbone comopound. Besides, chiral secondary amine-catalyzed cycloadditon reactions are widely used in synthesis of five and six membered hetero-cyclic compouds. In this paper, we mainly described the palladium-catalyzed cross-coupling reaction in the synthesis of the diaryl sulfoxides and sulfinyl thiophenes derivatives. And chiral secondary amine-catalyzed the enantioselective cycloaddition of phthalazinium dicyanomethanides with 2,4-dienals. The results are as follows:1. Palladium-catalyzed arylation of aryl sulfenate anions with aryl bromides (C-S bond formation)We described a palladium-catalyzed arylation of aryl sulfenate anions, which afforded diaryl sulfoxides in high yield (up to 96% yield). Key to success of this process is a fluoride triggered elimination strategy with aryl 2-(trimethylsilyl) ethyl sulfoxides to liberate the requisite aryl sulfenate anion intermediates. Various functional groups, including those with acidic protons, are well tolerated2. Palladium-catalyzed regio-selective C-H functionalization of sulfinyl thiophenes(C-C bond formation)A palladium-catalyzed arylation of sulfinyl thiophenes with aryl bromides has been developed. This protocol is effective for the selective synthesis of 2-monoarylated and 2,5-diarylated sulfinyl thiopene derivatives(up to 99% yield) with only 0.5% catalyst loading. Various functional groups are well tolerated.3. Chiral-secondary amine-catalyzed [3+2] Cycloaddition of phthalazinium dicyanomethanides with 2,4-Dienals (C-C bond formation)We reported a highly regio-and enatioselective [3+2] cycloaddition of phthalazinium dicyanomethanides with 2,4-dienals catalyzed by a commercially available MacMillan’s calalyst through a trienamine activation stragety(up to 92% yield and 98% ee). The reaction progress proceeds by way of 1,6-additon to linear 2,4-dienals affording the five stereogenic center and high control over stereochemistry.