Regiodivergent Hydration–Cyclization of Diynones under Gold Catalysis
作者:Marta Solas、Miguel A. Muñoz、Samuel Suárez-Pantiga、Roberto Sanz
DOI:10.1021/acs.orglett.0c02892
日期:2020.10.2
Skipped diynones, efficiently prepared from biomass-derived ethyl lactate, undergo a tandem hydration–oxacyclization reaction under gold(I) catalysis. Reaction conditions have been developed for a switchable process that allows selective access to 4-pyrones or 3(2H)-furanonesfrom the same starting diynones. Further application of this methodology in the total synthesis of polyporapyranone B was demonstrated
Ethyl lactate as a renewable carbonyl source for the synthesis of diynones
作者:Marta Solas、Samuel Suárez-Pantiga、Roberto Sanz
DOI:10.1039/c8gc03275k
日期:——
Ethyl lactate, a sustainable feedstock, serves as a highly attractive building block for the synthesis of value-added chemicals such as skipped diynones and, after gold-catalyzed transposition, conjugated diynones. Green solvents are involved in all steps and high yields are obtained for the final diynones which, in several cases, are isolated in a pure form without any purification.
Synthesis of 1,2,3-triazole-fused heterocycles viaPd-catalyzed cyclization of 5-iodotriazoles
作者:Jacqueline M. Schulman、Adam A. Friedman、Jane Panteleev、Mark Lautens
DOI:10.1039/c1cc16110e
日期:——
A convenient approach toward polycyclic frameworks containing fused 1,2,3-triazoles is described. The synthesis consists of a Cu-catalyzed cycloaddition and an intramolecular Pd-catalyzed direct arylation or Heck reaction, and affords the products in good to excellent yields.
A sustainable green methodology for the ‘one-pot’ syntheses of 1,2,3-triazolo 3-hydroxy-2-oxindoles from isatin–epoxides has been employed via a CuAAC reaction.
Rhodium-catalyzed cyclopropanations of 2-aryl-2H-chromenes with dialkyl malonate esters. A comparison of α-diazo derivatives and phenyliodonium ylides
作者:Sean Stokes、Rachel Mustain、Lydia Pickle、Keith T. Mead
DOI:10.1016/j.tetlet.2012.05.061
日期:2012.7
Rhodium-catalyzed reactions of 2-aryl-substituted 2H-chromenes with α-diazo esters prepared fromdimethyl and tert-butyl methyl malonates were investigated, and the results were compared with reactions carried out with phenyliodonium ylides prepared from the same esters. The phenyliodonium ylide prepared fromdimethylmalonate was found to give superior yields of cyclopropane products compared to the corresponding