Institute of Organic Chemistry, Justus-Liebig University , Heinrich-Buff-Ring 17, 35392 Giessen, Germany.
Org Lett. 2017 Nov 17;19(22):6156-6159. doi: 10.1021/acs.orglett.7b03034. Epub 2017 Oct 31.
This letter presents the side-chain iodination of electron-deficient benzylic hydrocarbons at rt using N-hydroxyphthalimide (NHPI) as radical initiator and 1,3-diiodo-5,5-dimethylhydantoin and 3-iodo-1,5,5-trimethylhydantoin (3-ITMH) as iodine source. Addition of a carboxylic acid increased the reactivity due to complex formation with and activation of 3-ITMH by proton transfer and halogen bond formation. No SAr reactions were observed under the employed reaction conditions. Our method enables convenient product isolation and gives 50-72% yields of isolated products.
这封信提出了使用 N-羟基邻苯二甲酰亚胺 (NHPI) 作为自由基引发剂和 1,3-二碘-5,5-二甲基海因和 3-碘-1,5,5-三甲基海因 (3-ITMH) 作为碘源，在室温下对缺电子苄基烃进行侧链碘化反应。添加羧酸由于质子转移和卤素键形成而与 3-ITMH 形成配合物并对其进行活化，从而提高了反应性。在所采用的反应条件下未观察到 SAr 反应。我们的方法便于产物分离，并得到 50-72%的分离产物收率。
