Journal of the American Chemical Society, Vol.136, No.40, 13971-13974, 2014
Catalytic Asymmetric alpha-Iminol Rearrangement: New Chiral Platforms
A series of 19 different asymmetric catalysts were screened in an effort to identify the first chiral catalyst for the rearrangement of alpha-hydroxy imines to alpha-amino ketones involving a 1,2-carbon shift. Although aluminate complexes of VAPOL, VANOL, and 7,7'-Bu(2)VANOL were quite effective catalysts giving up to 88% ee, the neplus ultra catalyst for this reaction was found to be a zirconium complex of VANOL which gives 97 to >99% ee diffraction study of the catalyst reveals that the zirconium exists as a homoleptic complex with three VANOL ligands and two protonated N-methyl imidazoles.