A gold-catalyzed alkyne-diol cycloisomerization for the synthesis of oxygenated 5,5-spiroketals

• Sami F. Tlais and
• Gregory B. Dudley

Beilstein J. Org. Chem. 2011, 7, 570–577, doi:10.3762/bjoc.7.66

• less effective. The use of methanol as solvent helped suppress the formation of the undesired furan by-product. This study provides yet another example of the advantages of gold catalysis in the activation of alkyne π-systems. Keywords: alkynes; cyclocondensation; cycloisomerization; gold-catalyzed

• challenges that required a focused study. For this thematic issue on gold catalysis in organic synthesis, we detail here the challenges and considerations involved in the cycloisomerization of alkynes to oxygenated spiroketals and outline our screening of various late transition metal catalysts and

• metal Lewis acids were less effective. This study provides yet another example of the advantages of gold catalysis in the activation of alkyne π-systems. Experimental 1H NMR and 13C NMR spectra were recorded in CDCl3 as the deuterated solvent. The chemical shifts (δ) are reported in parts per million

Gold film- catalysed benzannulation by Microwave- Assisted, Continuous Flow Organic Synthesis (MACOS)

• Gjergji Shore,
• Michael Tsimerman and
• Michael G. Organ

Beilstein J. Org. Chem. 2009, 5, No. 35, doi:10.3762/bjoc.5.35

• regioselective, and proceeds in good to excellent conversion. Keywords: benzannulation; flow synthesis; gold catalysis; microwave; thin metal film; Introduction Microwave-assisted organic synthesis (MAOS) has had a significant impact on organic and medicinal chemistry by dramatically shortening reaction times