Synthesis of extended polyphosphacumulenes.

Addition of two equivalents of (Me(3)Si)(2)CLiCl to the C-[(diphenyl) (diisopropylamino)phosphonio]-P-(diisopropylamino)phosphaalkene 2 affords the 1sigma(4),3sigma(3)-diphosphabuta-1,2,3-triene E1 in 55 % yield. Derivative E1 was fully characterized, including a single-crystal X-ray diffraction study. Alkylation of E1 with methyl trifluoromethanesulfonate gives rise to the first C-phosphonio-bis(methylene)phosphorane 5, which was isolated in 84 % yield. Because the second carbon center is also nucleophilic, cumulene E1 reacts as a "pincer" with BF(3)OEt(2), leading to the formation of a novel four-membered PCBC heterocycle 6 with a betaine-like structure. Addition of three equivalents of P-[diphenyl(diisopropylamino)]methylene phosphorane to (diisopropylamino)dichlorophosphane, followed by addition of one equivalent of CCl(4), and subsequent deprotonation with lithium hexamethyldisilazide gave rise to 1sigma(4),3sigma(3),5sigma(4)-triphosphapenta-1,2,3,4-tetraene F1, which was isolated in 62 % yield.

[1]  R. Appel,et al.  Die ersten Bis(methylen)phosphorane vom Typ RP[C(SiMe3)2]2 mit trikoordiniertem, pentavalentem Phosphor†‡ , 2006 .

[2]  G. Bertrand,et al.  C‐Phosphoniophosphaalkenes as Precursors of 1σ4,3σ2‐Diphosphaallenes: Scope and Limitations , 2005 .

[3]  T. Baumgartner,et al.  Unusual approaches to organophosphorus compounds: The surprising reactivity of bis(methylene)phosphoranes and related phosphoranylidene carbenoids , 2002 .

[4]  J. Escudié,et al.  Heavy allenes and cumulenes e=c=e' and e=c=c=e' (e = p, as, si, ge, sn; e' = C, N, p, as, o, s). , 2000, Chemical reviews.

[5]  G. Bertrand,et al.  Synthesis, Structure, and Reactivity of a 1σ4,3σ2‐Diphosphaallene , 2000 .

[6]  B. Bildstein,et al.  Tetraferrocenyl[5]cumulene, (Fc)2CCCCCC(Fc)2: Synthesis, Electrochemistry, and Reactivity, Including Nickel(0)-Promoted [3]Ferrocenophane Formation and [2+2] Cycloaddition with Fullerene C60 , 1999 .

[7]  V. Young,et al.  Nickel Complexes Containing New Carbon−Phosphorus Unsaturated Ligands: First Examples of Phosphavinylidene−Phosphorane [R3PCPR‘] and Phosphavinyl Phosphonium [C(H)(PR3)P(R‘)]+ Ligands , 1998 .

[8]  R. Pietschnig,et al.  FERROCENYLBIS(YLENE) PHOSPHORANES , 1997 .

[9]  E. Niecke,et al.  Reactions of an iminophosphoranylidene carbenoid , 1994 .

[10]  E. Niecke,et al.  Reaktionen eines Iminophosphoranyliden‐carbenoids , 1994 .

[11]  H. Bestmann,et al.  1,3‐Bis(triphenylphosphoranylidene)allene and Tribenzyl(4‐methyldiphenylphosphonio‐butadiynyl)borate, Stabilized C3 and C4: Confirmation of a Hypothesis , 1993 .

[12]  F. Hampel,et al.  1,3‐Bis(triphenylphosphoranyliden)allen und Tribenzyl(4‐methyldiphenylphosphoniobutadiinyl)‐borat, stabilisiertes C3 und C4 ‐die Bestätigung einer Hypothese , 1993 .

[13]  J. Escudié,et al.  Role of the conformation in the reactivity of 1,3‐diphosphapropenes , 1991 .

[14]  H. Grützmacher,et al.  Ein neuer Weg zu Phosphaalkenen , 1989 .

[15]  H. Pritzkow,et al.  A New Route to Phosphaalkenes , 1989 .

[16]  G. Märkl,et al.  1,4-Diphosphabutatrien , 1988 .

[17]  G. Märkl,et al.  1,4‐Diphosphabutatriene , 1988 .

[18]  G. Müller,et al.  Molecular Structure of a 1,3‐Diphosphaallene: (2,4,6‐tBu3C6H2)PCP(2,4,6‐tBu3C6H2), a Phosphorus Analogue of Carbon Disulfide , 1984 .

[19]  G. Müller,et al.  Molekülstruktur eines 1,3‐Diphosphaallens: (2,4,6‐tBu3C6H2)PCP(2,4,6‐tBu3C6H2), ein Phosphoranalogon zu Schwefelkohlenstoff , 1984 .

[20]  E. Niecke,et al.  Ein Phosphor(v)‐Derivat der Koordinationszahl 3: Bis(trimethylsily)amino‐bis(trimethylsilylimino)‐phosphoran , 1974 .

[21]  E. Niecke,et al.  A Phosphorus(V) Derivative Having Coordination Number 3: Bis(trimethylsilyl)aminobis(trimethylsilylimino)phosphorane , 1974 .

[22]  D. Seyferth,et al.  Halomethyl-metal compounds XXXVII. The trimethylsilyl-substituted chloromethyllithium reagents: Me3siccl2Li and (Me3Si)2CClLi☆☆☆ , 1970 .

[23]  H. Bestmann,et al.  Synthesis of Phosphonium Ylides , 1991 .

[24]  N. Inamoto,et al.  Isolation and characterisation of the first stable diphospha-allene: P,P′-bis(2,4,6-tri-t-butylphenyl)-1,3-diphospha-allene , 1984 .

[25]  R. Appel,et al.  P‐Chlor‐alkylidenphosphorane und (α‐Chloralkyl)phosphane, durch 1,2‐Chlorverschiebung ineinander überführbare Strukturisomere , 1983 .

[26]  R. Appel,et al.  The First Bis(methylene)phosphoranes of Type RP[C(SiMe3)2]2 with Tricoordinated Pentavalent Phosphorus , 1982 .

[27]  S. Patai.  The Chemistry of ketenes, allenes, and related compounds , 1980 .