A green method for the sulfination of allenic carbonyl compounds to access a wide variety of vinylic sulfones is developed. This reaction works in aqueousmedia under very mild conditions. This reaction is atom economic. A wide variety of vinylic sulfones could be obtained in moderate to excellent yields with wide functional group tolerance. The efficiency of this method is demonstrated in some reactions
Gold-Catalyzed Regioselective Synthesis of 2- and 3-Alkynyl Furans
作者:Yifan Li、Jonathan P. Brand、Jérôme Waser
DOI:10.1002/anie.201302210
日期:2013.6.24
Chemical Matching: C2‐ or C3‐alkynylated furans were selectively synthesized by using gold catalysis. Direct C–H alkynylation of furans was achieved with C2 selectivity, and a domino cyclization/alkynylation process starting from allenes gave C3‐alkynylated products. The exact matching of the structure of the gold catalyst and an electrophilic hypervalent iodine reagent was essential for success.
catalyzed carbonylation of 1,2-allenyl ketones 1 in the presence of p-benzoquinone (1 equiv) under a CO atmosphere (balloon) afforded difuranylketones 4 in moderate to good yields. Mechanistically, the electron-withdrawing nature of the acyl group should enhance the electrophilicity of the acylpalladium species B, and thus promote the oxypalladation of an additional molecule of 1, leading to the difuranyl
Room temperature Fe(NO3)3·9H2O/TEMPO/NaCl-catalyzed aerobic oxidation of homopropargylic alcohols
作者:Jinxian Liu、Shengming Ma
DOI:10.1016/j.tet.2013.08.082
日期:2013.11
and eco-friendly aerobicoxidation of homopropargylic alcohols using Fe(NO3)3·9H2O/TEMPO/NaCl as catalysts at roomtemperature under atmospheric pressure was developed affording corresponding homopropargylic ketones with moderate to good yields. Aryl, heteroaryl as well as alkyl 1,2-allenic ketones were obtained by the isomerization of corresponding terminal homopropargylic ketones through column chromatographic
使用的Fe homopropargylic醇的实际和生态友好的有氧氧化(NO 3)3 ·9H 2 O / TEMPO / NaCl的如在大气压下室温催化剂的开发得到对应homopropargylic酮与中度至良好的产率。芳基,杂芳基以及烷基1,2-丙二烯酮类通过柱层析后处理在硅胶上相应的端子homopropargylic酮的异构化获得的。
Selective Synthesis of 3-Methylene-2,3-dihydrofurans or 1,2,4-Trisubstituted Furans via Tandem Reactions of Allenic Ketones with α-Chloro β-Keto Esters or Ketones
作者:Xuesen Fan、Qiang Wang、Lei Yang
DOI:10.1055/s-0033-1340671
日期:——
Novel and efficient synthesis of functionalized furan derivatives have been developed in this paper. Promoted by K2CO3, allenic ketones underwent tandem reactions with 2-chloroacetoacetate or 3-chloropentane-2,4-dione to afford 3-methylene-2,3-dihydrofurans with high efficiency under remarkably mild conditions. When the same substrates were treated with potassium carbonate and triphenylphosphine, on