Nowicki Krzysztof, Grądecka Maja, Kurasz Patrycja, Wieczorkiewicz Paweł A, Dąbrowski Damian, Durka Krzysztof, Luliński Sergiusz
Faculty of Chemistry, Warsaw University of Technology, Noakowskiego 3, 00-664 Warsaw, Poland.
J Org Chem. 2025 Jun 13;90(23):7688-7699. doi: 10.1021/acs.joc.5c00501. Epub 2025 May 21.
Benzoxa- and thienoxaphosphaborinines, a new group of six-membered boron-phosphorus heterocycles, are reported. Their synthesis involved aromatic lithiation of appropriate 2-aryl-6-butyl[1.3.6.2]dioxazaborocans, followed by treatment with PhPCl and subsequent hydrolysis giving rise to (2-(phenylhydrophosphoryl)aryl)boronic acids. These intermediates exhibit nucleophilic character and undergo readily condensation reactions with aldehydes and ketones giving rise to target products. The mechanism of the latter reaction was studied by means of DFT calculations showing that activation of the carbonyl partner occurs through the formation of the hydrogen bond with the B(OH) group rather than through an interaction with the Lewis acid boron atom due to a plausible FLP-like behavior. The molecular structures of a few derivatives were determined by X-ray crystallography showing that in all cases, the molecules assemble through intermolecular BOH···O═P hydrogen bonds.
报道了苯并恶唑磷硼烷和噻吩恶唑磷硼烷，这是一类新型的六元硼磷杂环化合物。它们的合成涉及对适当的2-芳基-6-丁基[1.3.6.2]二氧杂硼杂环戊烷进行芳基锂化反应，随后用PhPCl处理并进行水解，生成(2-(苯基氢膦酰基)芳基)硼酸。这些中间体具有亲核特性，能与醛和酮轻松发生缩合反应，生成目标产物。通过密度泛函理论计算研究了后一反应的机理，结果表明，由于可能存在类似Frustrated Lewis Pair (FLP) 的行为，羰基反应物的活化是通过与B(OH)基团形成氢键实现的，而不是通过与路易斯酸性硼原子的相互作用。通过X射线晶体学确定了几种衍生物的分子结构，结果表明在所有情况下，分子都是通过分子间BOH···O═P氢键组装的。
