第1个回答 2009-02-10
March上面有介绍酰基化酰卤活性I>Br>Cl>F并不是绝对的，原因可能是在形成Wheland中间体后，进一步形成产物时，I的离去能力更强，C-I键能也最小，所以I活性更高，至于烷基化，可能是由于F的体积较小，配合M的能力较强，导致更易形成R+，所以F活性更高
LZ可参考以下文献
1、Challoway.N.O,JACS,59,1474(1937)
2、Brown and Jungk，JACS,77,5584(1955)
3、Yamase，Bull，Chem，Soc，Jpn，34，480（1961）
4、Corrio，Bull，Soc，Chim，Fr，821（1965）
文献1中的描述
We have found that for the acyl halides the order of activity for the halogens is as might be expected, I > Br > C1> F. The extreme sensitiveness of acetyl iodide to aluminum chloride caused a marked decomposition but did not materially interfere with the determination. For the alkyl halides the surprising order found was F>CI>Br>I. In fact, the iodine was so inert that n-butyl iodide did not react with benzene in eighteen hours in the presence of aluminum chloride at 29°C, though the other halides reacted at rapid rates at lower temperatures. It is also of interest to note that the n-butyl iodide was stable in the reaction and was recovered unchanged.本回答被提问者采纳