Diphospha‐Ureas from the Phosphaketene Ph₃GePCO

Abstract

The phosphaketene Ph3GePCO is shown to react with the phosphide KP(tBu)2 to generate the anion [Ph3GePC(O)P(tBu)2]− 1. This species reacts with CH3I or ClGePh3 to give the dissymmetric diphospha‐ureas (tBu)2PC(O)P(GePh3)(CH3) 2 and (Ph3Ge)2PC(O)P(tBu)2 3 respectively. Sequential treatment of 2 with a base and CH3I affords a route to (tBu)2PC(O)P(CH3)2 5. These species are products of the first modular diphospha‐urea synthesis. The subsequent thermal and photochemical reactivity of these species was also probed and described.

Double Phosphinoboration of CO2: A Facile Route to Diphospha‐Ureas

“…Subsequently, the reduction of dimeric phosphaketenes, RPCO was reported to give an alternative route to a diphospha‐urea . Although transition‐metal‐supported diphospha‐ureas have also been reported, we have recently described a synthetic route exploiting nucleophilic attack of the phosphaketene Ph 3 GePCO by phosphides and subsequent alkylation . In targeting new strategies to CO 2 reduction to diphospha‐ureas, we note that we had some time ago reported the reactions of the phosphinoboranes R 2 PB(C 6 F 5 ) 2 with H 2 through a FLP‐type reaction .…”

A Primary Acyl Phosphine Stabilized by a Phosphonium Ylide

“…The isolation of 1 stands in contrast to the corresponding reaction of the ylide Ph 3 PCH 2 with aryl isocyanates, which reacts in a 1:2 ratio affording the species Ph 3 PC(CONHAr) 2 [32] . While proton migration from the ylidic carbon to the nitrogen atom in this case [22] is analogous to that seen in the formation of 1 , the 1:1 stoichiometry seen in the formation of 1 is likely due to the poor conjugation between carbonyl group and P‐center in contrast to conjugated amide CONH bond of partial C=N double‐bond nature.…”

“…Quantum chemical calculations were conducted at the PW6B96-D3/def2-QZVP + COSMO-RS// TPSS-D3/def2-TZVP + COSMO level of theory in THF solution [31] to probe the reaction mechanism between Ph 3 GePCO and Ph 3 PCH 2 (Figure 1 The isolation of 1 stands in contrast to the corresponding reaction of the ylide Ph 3 PCH 2 with aryl isocyanates, which reacts in a 1:2 ratio affording the species Ph 3 PC-(CONHAr) 2 . [32] While proton migration from the ylidic carbon to the nitrogen atom in this case [22] is analogous to that seen in the formation of 1, the 1:1 stoichiometry seen in the formation of 1 is likely due to the poor conjugation All hydrogen atoms except those on the P-and ylidic carbon atoms are omitted for clarity. C: black; P: orange; O: red; Ge: pale pink; H: white.…”

“…[30] In our efforts we have found avenues to acylphosphines via the readily accessible phosphaketene reagent Ph 3 GePCO. In our syntheses, the GePh 3 -fragment has served as a P-protecting group, facilitating the synthesis of the phosphorus analogue of DMF, P,P-dimethylformylphos-phine, Me 2 PC(H)O (E), [21] diphospha-ureas, R 2 PC(O)PR' 2 (F) , [22] and the phosphaalkene, (Z)-tBu 2 PC(OSiPh 3 )P-(GePh 3 ). [23] Herein, we exploit this synthon to access a rare example of a isolable primary acylphosphine and the first devoid of a stabilizing heteroatom (Scheme 1 (c)).…”

A Primary Acyl Phosphine Stabilized by a Phosphonium Ylide

“…The isolation of 1 stands in contrast to the corresponding reaction of the ylide Ph 3 PCH 2 with aryl isocyanates, which reacts in a 1:2 ratio affording the species Ph 3 PC-(CONHAr) 2 . [32] While proton migration from the ylidic carbon to the nitrogen atom in this case [22] is analogous to that seen in the formation of 1, the 1:1 stoichiometry seen in the formation of 1 is likely due to the poor conjugation All hydrogen atoms except those on the P-and ylidic carbon atoms are omitted for clarity. C: black; P: orange; O: red; Ge: pale pink; H: white.…”