Cationic Phosphinidene as a Versatile P1 Building Block: [LC-P]+ Transfer from Phosphonio-Phosphanides [LC–P–PR3]+ and Subsequent LC Replacement Reactions (LC = N-Heterocyclic Carbene)

Publikation: Beitrag in FachzeitschriftForschungsartikelBeigetragenBegutachtung



Cationic imidazoliumyl(phosphonio)-phosphanides [LC-P-PR3]+ (1a-e+, LC = 4,5-dimethyl-1,3-diisopropylimidazolium-2-yl; R = alkyl, aryl) are obtained via the nucleophilic fragmentation of tetracationic tetraphosphetane [(LC-P)4][OTf]4 (2[OTf]4) with tertiary phosphanes. They act as [LC-P]+ transfer reagents in phospha-Wittig-type reactions, when converted with various thiocarbonyls, giving unprecedented cationic phosphaalkenes [LC-P═CR2]+ (5a-f[OTf]) or phosphanides [LC-P-CR(NR2)]+ (6a-d[OTf]). Theoretical calculations suggest that three-membered cyclic thiophosphiranes are crucial intermediates of this reaction. To test this hypothesis, treatment of [LC-P-PPh3]+ with phosphaalkenes, that are isolobal to thioketones, permits the isolation of diphosphirane salts 11a,b[OTf]. Furthermore, preliminary studies suggest that the cationic phosphaalkene [LC-P═CPh2]+ may be employed to access rare examples of η2-P═C π-complexes with Pd0 and Pt0 when treated with [Pd(PPh3)4] and [Pt(PPh3)3] for which analogous complexes of neutral phosphaalkenes are scarce. The versatility of [LC-P]+ as a valuable P1 building block was showcased in substitution reactions of the transferred LC-substituent using nucleophiles. This is demonstrated through the reactions of 5a[OTf] and 6c[OTf] with Grignard reagents and KNPh2, providing a convenient, high-yielding access to MesP═CPh2 (16) and otherwise difficult-to-synthesize 1,3-diphosphetane 17 and P-aminophosphaalkenes.


Seiten (von - bis)10364-10375
FachzeitschriftJournal of the American Chemical Society
PublikationsstatusVeröffentlicht - 10 Mai 2023

Externe IDs

Scopus 85156108099
ORCID /0000-0001-7323-7816/work/142257484
PubMed 37105536
WOS 000984335900001



  • X-ray crystal, P-31 chemical-shifts, Terminal-phosphinidene, Organophosphorus compounds, Wittig reaction, Coordination chemistry, Stable compound, Metal-complexes, Different fates, Phosphaalkenes