Experimental transition state for the B-chlorodiisopinocampheylborane (DIP-Cl) reduction
作者:Sean E. Stafford、Matthew P. Meyer
DOI:10.1016/j.tetlet.2009.03.216
日期:2009.6
Asymmetric reductions of prochiral ketones are important transformations in the syntheses of natural products, pharmaceuticals, and fine chemicals. B-Chlorodiisopinocampheylborane (DIP-Cl), a stoichiometric reagent that is capable of reducing prochiral aralkyl ketones with high selectivity. Here, we utilize a recently developed C-13 kinetic isotope effect (KIE) methodology to probe the symmetry breaking process inherent to this asymmetric reduction. Experimental KIEs and computed transition structures indicate significant roles for non-bonding interaction, specific directed orbital interactions, and hydrogen tunneling in this reaction. (C) 2009 Elsevier Ltd. All rights reserved.