Mechanisms for reactions of halogenated compounds. Part 4.[1] activating influences of ring-nitrogen and trifluoromethyl in nucleophilic aromatic substitution
作者:R.D. Chambers、P.A. Martin、J.S. Waterhouse、D.L.H. Williams、B. Anderson
DOI:10.1016/s0022-1139(00)82276-9
日期:1982.6
determined. Ring-nitrogen activates the system at points ortho-, meta- and para- to the point of substitution, in the ratios ortho- 6.2 × 104, meta- 8.5 × 102, and para- 2.3 × 105. Similarly a trifluoromethyl substituent is activating by a factor of 2.4 × 103 ortho- and 4.5 × 103 para- to the point of substitution.
已经测量了氨与各种氟化吡啶和二嗪在二恶烷水溶液中在25°下的反应速率常数。从结果确定了环氮(相对于CH)和三氟甲基(相对于-H)的活化作用。环氮在邻位点,间位点和对位点对位激活系统,比例为邻位6.2×10 4,间位8.5×10 2和对位2.3×10 5。类似地,三氟甲基取代基在取代点附近以2.4×10 3的邻位因子和4.5×10 3的因子被激活。