Gold Catalysis: Biarylphosphine Ligands as Key for the Synthesis of Dihydroisocoumarins
作者:A. Stephen K. Hashmi、Benjamin Bechem、Annette Loos、Melissa Hamzic、Frank Rominger、Hassan Rabaa
DOI:10.1071/ch13552
日期:——
A gold-catalyzed phenol synthesis was successfully used in the synthesis of dihydroisocoumarins for the first time. A large number of gold(i) complexes were prepared and tested; only complexes based on the biarylphosphine motif were successful.
Gold Catalysis: Dihydroisobenzofurans and Isochromanes by the Intramolecular Furan/Alkyne Reaction
作者:A. Stephen K. Hashmi、M. Wölfle、Filiz Ata、Melissa Hamzic、Ralph Salathé、Wolfgang Frey
DOI:10.1002/adsc.200600367
日期:2006.11
furyl alcohols and homofuryl alcohols was synthesized by reduction of furfurals or reaction of furyllithium compounds with epoxides and subsequent propargylation. The gold-catalyzed cycloisomerization of these products furnished dihydroisobenzofurans and isochromanes. Crystal structure analyses proved the sequence of the substituents for both classes of products. Unsaturated dicarbonyl compounds as side-products
Photooxygenation of 2-(beta-hydroxyalkyl) furans affords, in one synthetic operation and in high yields, 3-keto-tetrhydrofuran motifs via intramolecular Michael-type addition to the 1,4-enedione intermediate.
Gold catalysis: benzanellation versus alkylidenecyclopentenone synthesis
作者:A. Stephen K. Hashmi、Michael Wölfle
DOI:10.1016/j.tet.2009.08.074
日期:2009.10
A series of different furan-yn-ols were prepared by a three-step sequence. Their reaction with Gagosz's catalyst Ph3PAuNTf2 depends strongly on the substitution pattern of the Substrate and the quality of the leaving group. Benzofurans, alkylidenecyclopentenones or Meyer-Schuster type products can be obtained. Improving the leaving group quality leads to the preferred formation of benzofurans. (C) 2009 Elsevier Ltd. All rights reserved.
Functionalized 3(2H)-furanones via photooxygenation of (β-keto)-2-substituted furans: Application to the biomimetic synthesis of merrekentrone C
作者:Charis Gryparis、Ioannis N. Lykakis、Christina Efe、Ioannis-Panayotis Zaravinos、Theonymphi Vidali、Eugenia Kladou、Manolis Stratakis
DOI:10.1039/c1ob05567d
日期:——
Photooxygenation of (β-keto)-2-substituted furans leads, in a one pot operation, to functionalized 3(2H)-furanones with good to excellent yields. This methodology was applied as a key-step to the concise and biomimetic synthesis of the sesquiterpene merrekentrone C. The precursor to merrekentrone C, keto difuran, was synthesized using a cross coupling of α-iodo-3-acetylfuran with an alkenyl furan under Fenton-type conditions.