A mild and efficient aza-Diels-Alder reaction of N-benzhydryl imines with trans-1-methoxy-2-methyl-3-trimethylsiloxybuta-1,3-diene catalyzed by Yb(OTf)(3)

摘要

The aza-Diels-Aider reaction of trans-1-methoxy-2-methyl-3-trimethylsiloxybuta-1,3-diene with N-benzhydryl imines in the presence of Yb(OTf)(3) in toluene at room temperature gave the corresponding 2,5-disubstituted 2,3-dihydro-4-pyridones in high yields. This reaction can also be carried out with diene, aldehydes, and amine in a three-component one-pot reaction manner in moderate to high yields under solvent-free conditions. The relationship between Lewis acids and activity, solvents and catalyst loading were studied. Some investigation towards the reaction mechanism was discussed. (c) 2005 Elsevier Ltd. All rights reserved.