We report the influence of N-heterocyclic carbenes (NHCs) on the hydrolysis of a diphosphene TerP[double bond, length as m-dash]PTer (1; Ter = 2,6-Mes2C6H3; Mes = 2,4,6-Me3C6H2), a phosphorus-analogue of an alkene. The diphosphene 1 itself is completely inert towards water. However, NHCs have been found to activate 1 towards ready hydrolysis. While sterically less-encumbered NHCs react with 1 affording NHC-adducts which are in equilibrium with 1 in solution, sterically encumbered NHCs do not bind to 1 at all. Interestingly, in both of these situations hydrolysis of the P[double bond, length as m-dash]P motif proceeds efficiently. At low temperatures, sterically less-encumbered NHCs are catalytic while the sterically encumbered NHCs play a catalytic role at room temperature. To gain insight on this striking influence of NHCs on the hydrolysis of diphosphene detailed low-temperature 31P-NMR studies along with theoretical calculations have been carried out. In addition, systematic hydrolysis studies of all the NHCs used in this study have also been performed.

中文翻译：

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N-杂环卡宾（NHC）对二膦水解的影响。

我们报道了N-杂环卡宾（NHCs）对二膦TerP [双键，长度以m-虚线] PTer（1; Ter = 2,6-Mes2C6H3; Mes = 2,4,6-Me3C6H2的水解的影响），是烯烃的磷类似物。二膦1本身对水完全是惰性的。但是，已发现NHC可以活化1使其易于水解。尽管在空间上较少受累的NHC与1反应，得到的NHC加合物与溶液中的1处于平衡状态，但在空间上受累的NHC根本不与1结合。有趣的是，在这两种情况下，P [双键]的水解均有效地进行了长度为m-P的基序。在低温下，空间较弱的NHC在室温下起催化作用，而空间较弱的NHC在室温下起催化作用。为了深入了解NHC对二膦的水解的显着影响，已经进行了详细的低温31 P-NMR研究以及理论计算。另外，还对本研究中使用的所有NHC进行了系统的水解研究。