DIARYLIODONIUM SALTS .17. PHENYLATION OF 1,3-INDANDIONES
DIARYLIODONIUM SALTS .17. PHENYLATION OF 1,3-INDANDIONES
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DOI：
10.1021/ja00873a035
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发表时间：
1962-01-01
影响因子：
15
通讯作者：
GALTON, SA
中科院分区：
文献类型：
--
作者：
BERINGER, FM;HUANG, SJ;GALTON, SA
以前的工作表明，在叔丁醇中的酸性二酮和三酮的阴离子可以被二苯基碘鎓盐苯基化。在这些条件下，1，3-茚满二酮和2-苯基-1，3-茚满二酮（I）均转化为2，2-二苯基-1，3-茚满二酮（II），后一反应以93%的产率发生。提出了以下机理：离子对内的电子从碳负离子（R“）转移到碘鎓离子（ArlAr），得到一个自由基对，其成员主要产生ArR。在叔丁醇中，形成一些还原产物ArH;在异丙醇中形成更多的ArH。酒精。一些自由基从溶剂笼中逸出，随后结合形成ArR、RR和ArAr。热自由基清除剂氧（I的碳负离子对氧是惰性的）使苯基化产物II的产率降低到53%，而苯乙烯使II的产率降低到70%，并得到含有羰基的低分子量聚合物。本实验室以前的一篇文章4描述了用二苯基碘鎓盐对双甲酮、5二苯甲酰甲烷和三苯甲酰甲烷的阴离子进行苯基化。在叔丁醇中产率最高，在1和2醇中溶剂脱氢伴随碘鎓盐还原。本工作的一个主要目的是通过观察自由基清除剂氧和苯乙烯对产物分布的影响来阐明这种苯基化反应的机理。所选用的体系为1，3-茚满二酮及其2-苯基和2-乙氧羰基衍生物的阴离子与氯化二苯基碘鎓在叔丁醇中的显色体系。2-苯基-1，3-茚满二酮的反应将含有2-苯基-1，3-茚二酮钠盐6（I）和1当量氯化二苯基碘鎓 7的溶液加热回流，得到已知的非酸性2，2-二苯基-1，3-茚二酮8（II）。O- O
Previous work has shown that the anions of acidic di-and triketones in f-butyl alcohol can be phenylated by diphenyliodonium salts. Under these conditions 1, 3-indandione and 2-phenyl-l, 3-indandione (I) are both converted to 2, 2-diphenyl-1, 3-indandione (II), the latter reaction occurring in 93% yield. The following mechanism is proposed: electron transfer within an ion pair from a carbanion (R “) to an iodonium ion (ArlAr) to give a radical pair, the members of which largely give ArR. In f-butyl alcohol there is formed some reduced product, ArH; more is formed in prim, and sec. alcohols. Some radicals escape from the solvent cage, combining later to form ArR, RR and ArAr. Theradical scavenger, oxygen, to which the carbanion of I is inert, reduces theyield of phenylated product II to 53%, while styrene reduces the yield of II to 70% and gives polymers of low molecular weight containing carbonyl groups.Introduction.—A previous article4 from this Laboratory reportedthe phenylation of the anions of dimedone, 5 dibenzoylmethane and tribenzoylmethane with diphenyliodonium salts. Yields were best in f-butyl alcohol, as in 1 and 2 alcohols dehydrogenation of the solvent accompanied reduc-tion of the iodonium salt. A major aim of the present work has been to elucidate the mechanism of this phenylation by observing the change in the product distribution effected by the radical scaven-gers oxygen and styrene. The systemchosen was that of the anions of 1, 3-indandione and its 2-phenyl and 2-carbethoxy derivatives with diphenyliodonium chloride in f-butyl alcohol. Reaction of 2-Phenyl-1, 3-indandione.—A solu-tion containing the sodium salt of 2-phenyl-l, 3-indandione6 (I) and an equivalent of diphenyliodonium chloride7 was heated under reflux to give as the major product the known non-acidic 2, 2-diphenyl-1, 3-indandione8 (II). o- O