Nguyen MT, Spasyuk D, White B, Dudding T, Nikonov GI. Generation and reactivity of an elusive base-stabilised phosphinidene.
Dalton Trans 2021;
50:16613-16619. [PMID:
34748621 DOI:
10.1039/d1dt03181c]
[Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Reduction of phosphorus dichloride 6, supported by the diaryloxyphenyl group (OCO) featuring two bulky phenoxy wingtips, by PMe3, generates a reactive intermediate that behaves as a base-stabilized phosphinidene (OCO)P (5). Warming up a solution of this species in toluene to room temperature results in trimerization to give the isolable cyclic triphosphine [(OCO)P]3, whereas in situ trapping with 2,3-dimethylbutadiene-1,3 afforded a 3,4-dimethylphospholene-3. Investigation of the reduction of 6 by the phosphine PMe3 by NMR led to the observation of a persistent species between -10 °C and 10 °C. A DFT study of this process suggests that this compound cannot be the proposed phosphinidene 5, and is more likely the diphosphine (OCO)ClP-PCl(OCO) (12). Attempted reduction of 5 by the bulky carbene IPr resulted in unusual electrophilic substitution in the carbene olefin backbone by the chlorophosphinyl group.
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