Highly controlled living radical polymerization through dual activation of organobismuthines.
Highly controlled living radical polymerization through dual activation of organobismuthines.
复制标题
DOI：
10.1002/anie.200604473
复制
发表时间：
2007-02
影响因子：
--
通讯作者：
S. Yamago;Eiichi Kayahara;M. Kotani;B. Ray;Y. Kwak;A. Goto;T. Fukuda
中科院分区：
文献类型：
--
作者：
S. Yamago;Eiichi Kayahara;M. Kotani;B. Ray;Y. Kwak;A. Goto;T. Fukuda
第16族和第17族杂原子化合物（如有机硒化物、碲化物、溴化物和碘化物）的合成自由基化学一直是深入研究的主题，因为它们能够在温和条件下产生碳中心自由基。[1]相反，第15族杂原子化合物的合成自由基化学几乎是未知的。我们最近报道，有机锑是碳中心自由基的优良前体，并促进高度可控的活性自由基聚合。[2-4]这些结果促使我们研究涉及15族杂原子化合物的自由基反应，而不是有机锑。在自由基化学中，有机锑化合物的主要特征是它们能够与自由基发生有机锑基转移（GT）反应，生成新的碳中心自由基。[3a，B]尽管有机碲化物和碘化物被报道为迄今为止对GT和原子转移（AT）反应最具反应性的杂原子，[5-7]我们的结果表明有机锑化物比这些杂原子化合物更具反应性。上级转移能力导致更高的反应效率和控制GT和AT加成到炔和烯烃中，[5a]例如活性自由基聚合。[8]此外，GT和AT反应更快，杂原子在周期表上更低。[6a]因此，我们一直对有机铋的反应性感兴趣。我们在本文中报告，有机铋确实是碳中心自由基的优秀前体，并促进高度受控的活性自由基聚合;有机铋介导的活性自由基聚合（BIRP）中的控制水平显著高于有机锑、碲和碘介导的自由基聚合（分别为SBRP，[3] TERP，[9]和IRP，[10]）。虽然已经报道了几个涉及从有机铋生成自由基的例子，[11]但这是第一个在合成自由基化学中使用它们的例子。
Synthetic radical chemistry of Group 16 and 17 heteroatom compounds, such as organoselenides, tellurides, bromides, and iodides, has been the subject of intensive research because of their ability to generate carbon-centered radicals under mild conditions.[1] In contrast, the synthetic radical chemistry of Group 15 heteroatom compounds is virtually unknown. We recently reported that organostibines are excellent precursors for carbon-centered radicals and promote highly controlled living radical polymerization.[2–4] The results prompted us to examine radical reactions involving Group15 heteroatom compounds other than organostibines. The key feature of organostibines in radical chemistry is their ability to undergo organostibanyl group-transfer (GT) reactions with radicals to generate new carbon-centered radicals.[3a, b] Although organotellurides and iodides have been reported as being the most reactive heteroatoms towards the GT and atom-transfer (AT) reactions so far,[5–7] our results show that organostibines are more reactive than these heteroatom compounds. The superior transfer ability leads to higher reaction efficiencies and controls in GT and AT additions to alkynes and alkenes,[5a] such as living radical polymerization.[8] Furthermore, GT and AT reactions are faster with heteroatoms lower on the periodic table.[6a] Therefore, we have been interested in the reactivity of organobismuthines. We report herein that organobismuthines are indeed excellent precursors for carbon-centered radicals and promote highly controlled living radical polymerization; the level of control in organobismuthine-mediated living radical polymerization (BIRP) is considerably higher than that in organostibine-, tellurium-, and iodine-mediated radical polymerizations (SBRP,[3] TERP,[9] and IRP,[10] respectively). Although several examples involving the generation of radicals from organobismuthines have been reported,[11] this is the first example of the use of them in synthetic radical chemistry.