Fragmentation, catenation, and direct functionalisation of white phosphorus by a uranium(iv)-silyl-phosphino-carbene complex

Room temperature reaction of the uranium(iv)-carbene [U{C(SiMe3)(PPh2)}(BIPMTMS)(mu-Cl)Li(TMEDA)(mu-TMEDA)(0.5)](2) (1, BIPMTMS = C(PPh2NSiMe3)(2)) with white phosphorus (P-4) produces the organo-P-5 compound [P-5{C(SiMe3)(PPh2)}(2)][Li(TMEDA)(2)] (2) and the uranium(iv)-methanediide [U{BIPMTMS}{Cl}{mu-Cl}(2){Li(TMEDA)}] (3). This is an unprecedented example of cooperative metal-carbene P-4 activation/insertion into a metal-carbon double bond and also an actinide complex reacting with P-4 to directly form an organophosphorus species. Conducting the reaction at low temperature permits the isolation of the diuranium(iv) complex [{U(BIPMTMS)([mu-eta(2):eta(2)-P-2]C[SiMe3][PPh2])}(2)] (4), which then converts to 2 and 3. Thus, surprisingly, in contrast to all other actinide P-4 reactivity, although this reaction produces catenation overall it proceeds via P-4 cleavage to functionalised P-2 units. Hence, this work establishes a proof of concept synthetic cycle for direct fragmentation, catenation, and functionalisation of P-4.

Automated summary

In this study, a room temperature reaction between a uranium-carbene complex and white phosphorous was conducted to form an organophosphorus compound. This reaction demonstrated cooperative metal-carbene and P-4 activation, producing different compounds when carried out at low temperature. The findings provide insights into direct fragmentation, catenation, and functionalization of P-4, showcasing a novel synthetic cycle.