In the course of our study on the ene reaction of trifluoromethyl ketones, a trifluoromethyl group has been observed to behave as a larger substituent than commonly believed in the biomedicinal field. To estimate the steric effect of a trifluoromethyl group, we synthesized several trifluoromethyl ketones (RCOCF)3 and examined in detail their ene reaction with cyclohexene, a 1, 2-disubstituted ene having the least steric requirement. In this reaction, a trifluoromethyl group was found to behave as if it were a much larger substituent than a phynyl or isobutyl group and as large as a sec-butyl group.
在我们研究三
氟甲基酮的ene反应过程中,我们观察到三
氟甲基团在
生物医学领域中表现得比普遍认为的更大。为了评估三
氟甲基团的立体效应,我们合成了几种三
氟甲基酮(RCOCF3)并详细研究了它们与
环己烯的ene反应,
环己烯是一种1,2-二取代的ene,其立体要求最少。在这种反应中,发现三
氟甲基团表现得像是一个比苯基或异丁基大得多的取代基,几乎与仲丁基团一样大。