MPV reduction using Al-III-calix[4]arene Lewis acid catalysts: Molecular-level insight into effect of ketone binding

作者：Nandi Partha; Matvieiev Yuriy I; Boyko Vyacheslav I; Durkin Kathleen A; Kalchenko Vitaly I; Katz Alexander^*

来源：Journal of Catalysis, 2011, 284(1): 42-49.

DOI：10.1016/j.jcat.2011.08.013

• Catalytic reduction
• Aluminum
• Calix[4]arene
• Meerwein-Ponndorf-Verley (MPV) reaction
• Two-point binding
• Enantioselectivity

Catalytic Meerwein-Ponndorf-Verley (MPV) reduction using Al-III-calix[4]arene complexes is investigated as a model system that requires the bringing together of two different chemical species, ketone and alkoxide, within a six-membered transition state. Two-point versus one-point ketone binding is demonstrated to be the most salient feature that controls MPV catalysis rate. A 7.7-fold increase in rate is observed when comparing reactants consisting of a bidentate Cl-containing ketone and sterically and electronically similar but looser-binding ketones, which are substituted with H and F. The one-point and two-point nature of ketone binding for the various ketones investigated is independently assessed using a combination of structural data derived from single-crystal X-ray diffraction and OFT-based molecular modeling. Using MPV catalysis with inherently chiral calix[4]arenes, the effect of multiple point reactant binding on enantioselectivity is elucidated. A higher denticity of ketone binding appears to increase the sensitivity of the interplay between chiral active site structure and MPV reduction enantioselectivity.

• 出版日期2011-11-1