Catalytic enantioselective organozinc addition toward optically active tertiary alcohol synthesis.
A highly enantioselective organozinc (R2Zn) addition to a series of aldehydes and ketones was developed based on conjugate Lewis acid-Lewis base catalysis. Optically active secondary and tertiary alcohols were obtained in high yields with high enantioselectivities without Ti(IV) compounds. Bifunctional chiral 3,3'-diphosphoryl-BINOL ligands were designed and prepared through a phospho-Fries rearrangement as a key step. On the other hand, bifunctional chiral phosphoramide ligands were designed and prepared from L-valine. Mechanistic studies were performed by X-ray analyses of Zn(II) cluster and chiral ligands, a 31P NMR experiment on Zn(II) complexes, and stoichiometric reactions with some chiral or achiral Zn(II) complexes to propose a transition state assembly that includes monomeric active intermediates.
Graduate School of Engineering, Nagoya University, Furo-cho, Chikusa, Nagoya, 464-8603, Japan.
Manabu
M
Hatano
Kazuaki
K
Ishihara
D000438:Alcohols / Q000138:chemical synthesis*; D000447:Aldehydes / Q000737:chemistry; D002384:Catalysis; D018360:Crystallography, X-Ray; D007659:Ketones / Q000737:chemistry; D008024:Ligands; D009682:Magnetic Resonance Spectroscopy; D008956:Models, Chemical; D009284:Naphthols / Q000138:chemical synthesis*; D009942:Organometallic Compounds / Q000737:chemistry*; D010766:Phosphorylation; D013237:Stereoisomerism; D015032:Zinc / Q000737:chemistry*
D000438:Alcohols; D000447:Aldehydes; C406944:BINOL, naphthol; D007659:Ketones; D008024:Ligands; D009284:Naphthols; D009942:Organometallic Compounds; D015032:Zinc