An efficient synthetic methodology of chiral isoquinuclidines by the enantioselective Diels-Alder reaction of 1,2-dihydropyridines using chiral cationic palladium-phosphinooxazolidine catalyst

The DA reaction of 1-phenoxycarbonyl-1,2-dihydropyridine with 1-substituted 2-acryloylpyrazolidin-3-ones using cationic chiral Pd-phosphinooxazolidine catalyst A afforded chiral isoquinuclidines B with an excellent enantioselectivity (up to 97% ee). Furthermore, B was transformed to chiral piperidine C bearing three chiral carbon centers in the structure.