Bogdanov Viktor P, Semivrazhskaya Olesya O, Belov Nikita M, Troyanov Sergey I, Markov Vitaliy Yu, Ioffe Ilya N, Kemnitz Erhard, Goryunkov Alexey A
Chemistry Department, M. V. Lomonosov Moscow State University, Leninskie Gory, 1-3, 119991, Moscow, Russia.
Institute of Chemistry, Humboldt University Berlin, Brook-Taylor-Str. 2, 12489, Berlin, Germany.
Chemistry. 2016 Oct 17;22(43):15485-15490. doi: 10.1002/chem.201602351. Epub 2016 Sep 8.
The homofullerene compound cis-2-C (CF ) , which has an unusual kind of open/closed valence tautomerism undergoes consecutive regioselective hydrogenation at bridgehead carbon atoms upon reduction with Zn/Cu couple in H O-toluene mixture. The tautomerism barrier in cis-2-C (CF ) is negligible in the neutral state, whereas negative charging both impedes tautomeric transformation and promotes regioselective addition of electrophilic species at the bridgehead carbon atoms. In light of this observation, two novel homofullerene derivatives, mixed [6,6]-open/closed C (CF ) H and [6,6]-open cis-2-C (CF ) H , were synthesized and their structures were unambiguously determined by means of single crystal X-ray crystallography and NMR spectroscopy.
具有一种不寻常的开/关价互变异构的富勒烯化合物顺式-2-C（CF），在用锌/铜偶合剂在水-甲苯混合物中还原时，桥头碳原子会发生连续的区域选择性氢化。顺式-2-C（CF）中的互变异构能垒在中性状态下可忽略不计，而负电荷既阻碍互变异构转化，又促进桥头碳原子上亲电物种的区域选择性加成。基于这一观察结果，合成了两种新型富勒烯衍生物，混合的[6,6]-开/关C（CF）H和[6,6]-开式顺式-2-C（CF）H，并通过单晶X射线晶体学和核磁共振光谱明确确定了它们的结构。
