Gold-Catalyzed Cyclization-Cycloaddition Cascade Reactions of Allenyl Acetals with Nitrones
作者:Dhananjayan Vasu、Rai-Shung Liu
DOI:10.1002/chem.201201777
日期:2012.10.22
Gold and silver: When allenyl acetals and nitrones are treated with a catalytic amount of a gold complex and a silver salt they react through a cyclization—cycloaddition cascadereaction to give a mixture of diastereomeric tricyclic products. The mixture converges to a single product upon acid hydrolysis (see scheme). The key intermediate is postulated to be a 1‐methoxyfulvene species.
Gold-Catalyzed Dealkoxylative Carbocyclization/[3+3] Annulation Cascade of Acetal-Allene or Ketal-Allene Substrates
作者:Tse-Min Teng、Ming-Shiun Lin、Dhananjayan Vasu、Sabyasachi Bhunia、Ting-An Liu、Rai-Shung Liu
DOI:10.1002/chem.201000041
日期:2010.4.26
Rapid construction: We report the first successful implementation of a catalytic tandem carbocyclization/annulationcascade reaction (e.g., see scheme) using acetal–allene or ketal–allenesubstrates through a dealkoxylative mode. This gold catalysis enables a rapid stereocontrolled construction of oxacyclic or carbocyclic frameworks.