Reaction of bis(trifluoromethyl)amino-oxyl with t-butylbenzene, 2,2-diphenylpropane, benzylcyclopropane and some related alcohols

Abstract

Reaction of the oxyl (CF 3) 2NO· ( 1) with t-butylbenzene ( c. 3:1 molar ratio) at room temperature gives the hydroxylamine (CF 3) 2NOH ( 3) (43% on oxyl) and a multicomponent higher-boiling mixture containing the substitution product (CF 3) 2NOCH 2CMe 2Ph ( 3) (28% on arene), and the compounds 3-(CF 3) 2NC 6H 4CMe 3 ( 5) (8% on arene) and 4-(CF 3) 2NC 6H 4CMe 3 ( 6) (6% on arene). The reaction with 2,2-diphenylpropane ( c. 4:1 molar ratio) at 70–80 °C affords hydroxylamine 3 (45% on oxyl) and a complex higher-boiling mixture, from which only the substitution product (CF 3) 2NOCH 2CMePh 2 ( 7) (36% on arene) could be isolated. In contrast, the reaction of oxyl 1 with benzylcyclopropane at room temperature is clean and gives hydroxylamine 3 (49% on oxyl) and the substitution product CH 2CH 2C HCH(Ph)ON(CF 3) 2 ( 8) (95% on cyclopropane). From the reactions of oxyl 1 with 2-phenylpropan-2-ol (2:1 molar ratio), cyclopropylmethanol ( c. 4:1 molar ratio) and 1-cyclopropylethanol (2:1 molar ratio) at room temperature, apart from hydroxylamine 3, the isolated products are a mixture of dimers of α-methylstyrene ( 10- 12) (30% on ol) and the 2:1 adduct of oxyl 1 and α-methylstyrene, i.e. (CF 3) 2NOCH 2CMe(Ph)ON(CF 3) 2 ( 9) (50% on ol); the ester CH 2CH 2C HCO 2N(CF 3) 2 ( 13) (99% on ol); and the ketone CH 2CH 2C HCOMe ( 15) (60% on ol), respectively.