Trifluoroacetic Acid-Promoted Synthesis of 3-Hydroxy, 3-Amino and Spirooxindoles from α-Keto-N-Anilides
摘要:
Ketoanilides containing alkyl side chains were readily cyclized to 3-hydroxy-2-oxindoles or spirooxindoles by a single or double intramolecular Friedel-Crafts reaction in the presence of trifluoroacetic acid (TFA) at room temperature or at 45 degrees C. alpha-Iminocarboxamides, generated in situ from ketoamides, cyclized similarly to 3-aminooxindoles under identical conditions,
Highly Diastereo- and Enantioselective Organocatalytic Michael Addition of α-Ketoamides to Nitroalkenes
作者:Olivier Baslé、Wilfried Raimondi、Maria del Mar Sanchez Duque、Damien Bonne、Thierry Constantieux、Jean Rodriguez
DOI:10.1021/ol102289g
日期:2010.11.19
The first organocatalytic enantio- and diastereoselective conjugate addition of α-ketoamides to nitroalkenes has been achieved using a bifunctional amino thiourea catalyst. In this new approach, the substrate amide proton plays a critical role in the formation of the Michael anti-adducts in high yields and high stereoselectivities. To illustrate the high synthetic potential of this methodology, the