Palladium(<scp>II</scp>)-catalysed asymmetric cyclisation of 2-allylphenols by the use of optically active β-pinene

Abstract

The palladium(II)-catalysed asymmetric cyclisation of 2-(but-2-enyl)phenol (1) to optically active 2,3-dihydro-2-vinylbenzofuran (3) can be achieved in 12% optical yield by using a catalytic amount of (–)-β-pinene, while in the presence of excess of β-pinene, cyclisation of (1) does not occur.