The rates of reduction of 17 aryl trifluoromethyl ketones by sodium borohydride in 2- propanol have been measured. The rho (ρ) value is+ 3.12, excluding the 4-amino and 4- dimethylamino groups, which both lower the rate to a greater extent than their σ values predict. The close correspondence between substituent effects for hydride addition in the methyl and trifluoromethyl series (excluding the amino groups) suggests that normal ...
