Imino- and aminomethylphenylboronic acids: stabilizing effect of hydrogen bonds

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• 作者：Agnieszka Adamczyk-Wo藕niak^a ; Micha艂 K. Cyra艅ski^b ; Beata T. Fr膮czak^b ; Agnieszka Lewandowska^a ; Izabela D. Madura^a ; Andrzej Sporzy艅ski^a ; ^{spor@ch.pw.edu.pl}
• 关键词：Boronic acids ; Hydrogen bond ; B&minus ; N bond ; Schiff bases ; Mannich bases ; MP2/6-31+G** ; SESE
• 刊名：Tetrahedron
• 出版年：2012
• 期刊代码：107_00404020
• 类别：ch
• 出版时间：13 May, 2012
• 卷：68
• 期：19
• 页码：3761-3767
• 文件大小：827 K

摘要

ortho-Iminomethylphenylboronic acids were synthesized from the reaction of 2-formyl-phenylboronic acid with primary aromatic amines. Reduction of these compounds yielded the corresponding aminomethylphenylboronic acids. For both types of the compounds, the crystal structure was determined by single crystal X-ray diffraction method. Hydrogen-bonded dimers with an additional intramolecular B-O-H鈥 hydrogen bond have been observed. Calculations at MP2/6-31+G** level proved that the most stable form is that with the above-mentioned intramolecular hydrogen bond while the form with dative N鈫払 bond is less favoured. Since the calculated energy difference is small, the competition between possible forms was analyzed in terms of substituent effect stabilization energy (SESE). In the case of p-iminomethylphenylboronic acid, both hydroxyl groups are engaged in intermolecular O-H鈥 interactions resulting in a supramolecular ribbon motif.