A highly anti-selective asymmetric Henry reaction catalyzed by a chiral copper complex: applications to the syntheses of (+)-spisulosine and a pyrroloisoquinoline derivative.

A highly anti-selective asymmetric Henry reaction has been developed, affording synthetically versatile β-nitroalcohols in a predominately anti-selective manner (mostly above 15:1) and excellent ee values (mostly above 95%). Moreover, the anti-selective Henry reaction was carried out in the presence of water for the first time with up to 99% ee. The catalytic mechanism was proposed based on the detection of the intermediates by extractive electrospray ionization mass spectrometry (EESI-MS). Furthermore, the anti adducts have been successfully transformed into the biochemically important (+)-spisulosine and a pyrroloisoquinoline derivative.