A novel selective aza-Morita-Baylis-Hillman (aza-MBH) domino reaction and aza-MBH reaction of N-sulfonated imines with acrolein catalyzed by a bifunctional phosphine organocatalyst

Article abstract of DOI:10.1002/chem.200800753

An efficient, bifunctional phosphine organocatalyst catalyzed aza-MBH reaction and aza-MBH domino reaction was developed between N-sulfonated imines and acrolein under mild conditions in moderate to excellent yields. Acrolein was added to a solution of N-(2-chlorobenzylidene)-4-methylhenzenesulfonamide and catalyst LBBA in CHCl₃. The stirring was maintained at room temperature until completion of the reaction. The residue was purified by a flash column chromatography to yield 3a as a colorless solid. The OH group is utilized to stabilize the intermediate A through hydrogen bonding. The Michael addition of A with N-sulfonated imine gives intermediate B, when THF is used as the solvent. The aza-MBH/Michael/aldol/dehydrate domino reaction also provides an efficient method to synthesize tetrahydropyridine derivatives, which can be used as building blocks in organic synthesis.