C-carboranylation of a quasi-aromatic iron(II) cage complex and its organic aromatic analog by the metal-catalyzed (promoted) cross-coupling reactions

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• 作者：Simyon V. Svidlov^a ; Oleg A. Varzatskii^b ; Tamara V. Potapova^a ; Anna V. Vologzhanina^c ; Sergey S. Bukalov^c ; Larisa A. Leites^c ; Yan Z. Voloshin^c ; ^{voloshin@ineos.ac.ru" class="auth_mail} ; Yurii N. Bubnov^a ; ^c
• 关键词：Macrocyclic compounds ; Clathrochelates ; Ligand reactivity ; Carboranylation ; Cross-coupling reaction
• 刊名：Inorganic Chemistry Communications
• 出版年：May, 2014
• 年：2014
• 卷：43
• 期：Complete
• 页码：142-145
• 全文大小：430 K

文摘

One-pot reaction a quasi-aromatic diiodoclathrochelate precursor with the carboranylating agent, generated in situ from equimolar amounts of lithium 1-ortho-carboranyl and trimethoxyborate, in the presence of a palladium catalyst afforded a ribbed-functionalized iron(II) mono-ortho-carboranoclathrochelate. Such a formation of 小(carborane)C(clathrochelate) bond is accompanied by hydrodeiodination in a vicinal position and a monomethinemonocarborane macrobicyclic complex was isolated and characterized by the single crystal X-ray diffraction. The geometry of its FeN₆-coordination polyhedron is intermediate between a trigonal prism and a trigonal antiprism with the distortion angle 蠁 of 24.9掳 and the height h of this polyhedron is equal to 2.32 脜; FeN distances vary from 1.889(2) to 1.921(2) 脜 and the average bite angle 伪 is approximately 39.1掳. The model reaction of this carboranylating agent with 4-iodobiphenyl, giving the corresponding aryl carborane, proceeds only in vigorous reaction conditions with a palladium catalyst and copper(I) iodide as a promotor. The compounds obtained were characterized using elemental analysis, ESI and EI mass spectrometry, IR, Raman, UV-vis, ¹H, ¹¹B, ¹⁹F and ¹³C{¹H} NMR spectroscopy. Thus, palladium-catalyzed Suzuki-Miyaura (copper-promoted in the case of an aryl iodide) cross-coupling reactions of a generated in situ derivative of carboranylboronic ester have been successfully used, for the first time, for one-pot synthesis of a quasi-aromatic hybrid carboranoclathrochelate with an inherent polyhedral ribbed substituent and its aromatic analog 4-(1-ortho-carboranyl)biphenyl. The developed strategy has been then found useful in the organic chemistry as a versatile approach towards carborane-based organic compounds.