Department of Chemistry, Indian Institute of Technology Kanpur, Kanpur 208016, India.
Dalton Trans. 2018 Aug 29;47(34):11917-11924. doi: 10.1039/c8dt01851k.
A bromo-capped metal-metal bonded diruthenium(i,i) complex Ru2(CO)4(PIN)2Br2 (1) (PIN = 1-isopropyl-3-(5,7-dimethyl-1,8-naphthyrid-2-yl)imidazol-2-ylidene) generates bromine with N-bromosuccinimide (NBS) at room temperature. Cycloalkene and stilbene are readily brominated by stoichiometric reactions with 1 and NBS. An analysis of the dibrominated products suggests the formation of cyclic bromonium intermediates indicating in situ Br2 generation. Complex 2, an iodide analogue of 1, is also synthesized. The reaction of 2 with N-iodosuccinimide releases I2, which is confirmed by the starch-iodine test. The catalytic utility of 1 is examined for the bromination of phenol. Catalyst 1, in combination with NBS and base, exhibits regioselectivity towards monobrominated products. Furthermore, efficient olefin aziridination is demonstrated utilizing catalyst 1 in the presence of NBS, K2CO3 and TsNH2.
一个溴代金属-金属键合的双钌(i,i)配合物 Ru2(CO)4(PIN)2Br2 (1)（PIN = 1-异丙基-3-(5,7-二甲基-1,8-萘啶-2-基)咪唑-2-亚基）在室温下与 N-溴代丁二酰亚胺 (NBS) 生成溴。环烯烃和二苯乙烯通过与 1 和 NBS 的化学计量反应很容易被溴化。二溴化产物的分析表明形成了环状溴鎓中间体，表明原位生成 Br2。1 的碘化物类似物 2 也被合成。2 与 N-碘代丁二酰亚胺的反应释放出 I2，这通过淀粉-碘测试得到证实。1 的催化用途用于苯酚的溴化反应。催化剂 1 与 NBS 和碱一起，对单溴化产物表现出区域选择性。此外，在 NBS、K2CO3 和 TsNH2 的存在下，利用催化剂 1 有效地进行了烯烃氮丙啶化。
