Sigmatropic Rearrangements of Hypervalent-Iodine-Tethered Intermediates for the Synthesis of Biaryls
Sigmatropic Rearrangements of Hypervalent-Iodine-Tethered Intermediates for the Synthesis of Biaryls
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DOI：
10.1002/anie.201801132
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发表时间：
2018-04-16
影响因子：
16.6
通讯作者：
Yorimitsu, Hideki
中科院分区：
文献类型：
--
作者：
Hori, Mitsuki;Guo, Jing-Dong;Yorimitsu, Hideki
芳基碘烷与苯酚的无金属脱氢偶联反应合成了2-羟基-2-碘联苯。该反应通过高价碘原子上的配体交换和[3，3]S型重排进行，具有完全的区域选择性。这种偶联与mCPBA的原位氧化相结合，能够方便地将碘芳烃转化为所需的联芳基。得到的联芳基在很近的位置具有可转化的碘和羟基，因此在合成上是有用的，例如-扩展呋喃和取代的[5]螺烯的受控合成。密度泛函理论计算清楚地表明，重排是顺式的，C-C键的形成和I-O键的断裂是协调进行的。醋酸被认为是该方案的最佳溶剂，它使碘原子更具阳离子，从而加速了S型重排。
Metal-free dehydrogenative couplings of aryliodanes with phenols to afford 2-hydroxy-2-iodobiaryls have been developed. This reaction proceeds through ligand exchange on the hypervalent iodine atom followed by a [3,3]sigmatropic rearrangement and with complete regioselectivity. This coupling, in combination with insitu oxidation by mCPBA, enables the convenient conversion of iodoarenes into desirable biaryls. The obtained biaryls have convertible iodo and hydroxy groups in close proximity, and are thus synthetically useful, as exemplified by the controlled syntheses of -extended furans and a substituted [5]helicene. DFT calculations clearly revealed that the rearrangement is sigmatropic, with C-C bond formation and I-O bond cleavage proceeding in a concerted manner. Acetic acid, which was found to be the best solvent for this protocol, renders the iodine atom more cationic and thus accelerates the sigmatropic rearrangement.