Photo-initiated addition of 2-propanol to two fluoroolefinic compounds, i.e. methyl 2,4,4,5,6,6-hexafluoro-3-oxa-2-(trifluoromethyl)hex-5-enoate (IV) containing perfluoroallyloxy group and 8,9-dichloro-1,1,2,4,4,5,7,7,8,9,9-undecafluoro-3,6-dioxa-5-(t rifluoromethyl)dodec-1-ene (V) containing trifluorovinyloxy group were used to verify a free-radical chain mechanism by means of quantum yield measurements based on substrate-decay kinetic. UV-Light energy (254 nm) was transferred to the reaction system via triplet-excited acetone. Quantum yields Fi of the addition products (X, XI) reached values 68 and 42, respectively, and thus confirmed the chain mechanism. The olefinic compounds IV and V were synthesized on the basis of the reaction of 2,3-dichloro-2,3,3-trifluoropropanoyl fluoride (I) with hexafluoropropene-1,2-oxide. The photoaddition of 2-propanol to both olefins took place with complete regioselectivity.
将2-
丙醇光引发加成到两种含
氟烯烃基团的化合物中,即甲基2,4,4,5,6,6-六
氟-3-氧-2-(三
氟甲基)己-5-烯酸酯(IV)含有
全氟烯氧基团和8,9-二
氯-1,1,2,4,4,5,7,7,8,9,9-十一
氟-3,6-二氧-5-(三
氟甲基)十二碳-1-烯(V)含有
三氟乙烯氧基团,用于通过底物衰减动力学的量子产率测量验证自由基链机制。紫外光能量(254 nm)通过三重激发
丙酮传递到反应系统中。加成产物(X,XI)的量子产率Fi分别达到68和42,从而确认了链机制。基于2,3-二
氯-2,3,3-三
氟丙酰
氟与
六氟丙烯-1,2-氧化物反应合成了烯烃化合物IV和V。2-
丙醇对两种烯烃的光加成过程具有完全的区域选择性。