English Laura E, Pajak Aleksandra, McMullin Claire L, Lowe John P, Mahon Mary F, Liptrot David J
Department of Chemistry, University of Bath, Bath, BA2 7AY, UK.
Centre for Sustainable and Circular Technologies, Bath, BA2 7AY, UK.
Chemistry. 2022 May 16;28(28):e202200376. doi: 10.1002/chem.202200376. Epub 2022 Apr 6.
Thermolysis of a 1,3-dioxa-2-phospholane supported by the terphenyl ligand Ar (Ar =[C H -2,6-(C H -2,6-iPr )]) at 150 °C gives [Ar PO ] via loss of ethene. [Ar PO ] was characterised by X-ray crystallography and NMR spectroscopy; it contains a 4-membered P-O-P-O ring and is the isostructural oxygen analogue of Lawesson's and Woollins' reagents. The dimeric structure of [Ar PO ] was found to persist in solution through VT NMR spectroscopy and DOSY, supported by DFT calculations. The addition of DMAP to the 1,3-dioxa-2-phospholane facilitates the loss of ethene to give Ar (DMAP)PO after days at room temperature, with this product also characterised by X-ray crystallography and NMR spectroscopy. Replacement of the DMAP with pyridine induces ethene loss from the 1,3-dioxa-2-phospholane to provide gram-scale samples of [Ar PO ] in 75 % yield in 2 days at only 100 °C.
在150°C下，由三联苯配体Ar（Ar = [C₆H₃-2,6-(C₆H₃-2,6-iPr₂)₂]）支撑的1,3-二氧杂-2-磷杂环戊烷经热解，通过乙烯的损失生成[Ar₂P₂O₂]。[Ar₂P₂O₂]通过X射线晶体学和核磁共振光谱进行了表征；它含有一个四元P-O-P-O环，是Lawesson试剂和Woollins试剂的等结构氧类似物。通过变温核磁共振光谱和扩散排序光谱（DOSY），并得到密度泛函理论（DFT）计算的支持，发现[Ar₂P₂O₂]的二聚体结构在溶液中持续存在。在室温下放置数天后，向1,3-二氧杂-2-磷杂环戊烷中加入4-二甲氨基吡啶（DMAP）促进乙烯的损失，生成Ar(DMAP)PO，该产物也通过X射线晶体学和核磁共振光谱进行了表征。用吡啶取代DMAP会促使1,3-二氧杂-2-磷杂环戊烷中的乙烯损失，在仅100°C下2天内以75%的产率提供克级规模的[Ar₂P₂O₂]样品。
