Development of Novel Radical Chemistry Utilizing the Heavy Group 15 Heteroatom Compounds

第16族和第17族杂原子化合物（例如有机硒化物、碲化物、溴化物和碘化物）的合成自由基化学在过去几十年中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。相比之下，第15族杂原子化合物的合成自由基化学几乎是未知的，并且它们的合成应用完全未被探索。本研究旨在阐明自由基条件下有机锑和有机铋等15族重杂原子化合物在活性聚合物和有机小分子精确合成中的应用，设计并合成了几种新的用于活性自由基聚合的有机锑和铋链转移剂。它们促进了各种乙烯基单体，如苯乙烯衍生物、（甲基）丙烯酸酯衍生物和N-乙烯基酰胺的高度受控的活性自由基聚合， ...更多信息 具有由单体/链转移剂的比率预测的受控分子量和非常窄的分子量分布的聚合物。单体家族的高度通用性和与极性官能团的高度相容性使得这些化合物对于合成具有致密官能度的结构明确的大分子非常有用。观察到的高控制归因于这些杂原子化合物对与聚合物端基的均裂取代反应（退化链转移反应）的高反应性;快速反应使得可以延长具有相似链长的所有聚合物链。的均裂取代反应的速率常数是最快的有机铋其次是有机锑，有机碲，然后有机碘，这个顺序是一致的控制水平的活性自由基聚合使用这些杂原子化合物。它们还显示出对与碳中心自由基的均裂取代反应的优异反应性。由于它们的高反应活性，它们在活性自由基聚合中作为助催化剂，增加了对分子量分布的控制，并在可控的条件下合成了分子量较大的聚合物.这些结果清楚地表明，重15族杂原子化合物是碳中心自由基的优良前体，在自由基反应中也具有相当大的合成用途.少

Synthetic radical chemistry of group 16 and 17 heteroatom compounds, such as organoselenides, tellurides, bromides, and iodides, has been the subject of intensive research over the past several decades because of their ability to generate carbon-centered radicals under mild conditions. In contrast, the synthetic radical chemistry of group 15 heteroatom compounds is virtually unknown, and their synthetic applications are totally unexplored. This research is aimed to clarify the synthetic utilities of heavier group 15 heteroatom compounds, such as organostibines and organobismuthines, under radical conditions for the precise synthesis of living polymers and small organic molecules.Several new organostibine and bismuthine chain transfer agents for living radical polymerization have been designed and synthesized. They promoted highly controlled living radical polymerization of various vinyl monomers, such as styrene derivatives, (meth)acrylate derivatives, and N-vinylamides, giving living … More polymers with controlled molecular weights as predicted by the ratio of monomer/chain transfer agent and very narrow molecular weight distributions. The high versatility for monomer families and high compatibility to polar functional groups make these compounds highly useful for the synthesis of structurally well defined macromolecules with dense functionalitics. The observed high control has been attributed to the high reactivity of these heteroatom compounds towards the homolytic substitution reaction (the degenerative chain transfer reaction) with polymer end radicals; the fast reaction makes it possible to elongate all of the polymer chains with similar chain lengths. The rate constant for the homolytic substitution reaction is fastest in organobismuthines followed by organostibines, organotelluriums, and then organoiodines, and this order is consistent with the level of control of living radical polymerization using these heteroatom compounds.Reactivities of distibines and thiobismuthines have been also examined. They have also shown excellent reactivity towards the homolytic substitution reaction with carbon centered radicals. Due to the high reactivity, they have served as cocatalysts in the living radical polymerization to increase the control of molecular weight distribution and to synthesize polymers with ultrahigh molecular weights under controlled manner.These results clearly demonstes that heavier group 15 heteroatom compounds are excellent precursors for carbon centered radicals and also possess considerable synthetic utilities in radical reactions. Less