TY - JOUR
T1 - Phosphinomethanides and group 15 element halides
T2 - Redox reactions, rearrangements and novel heterocycles
AU - Karsch, H. H.
AU - Witt, E.
N1 - Funding Information:
We thank Mr. J. Riede for X-ray data collection and Dr. M. Heckel, Dr. R. Ficker, Dr. A. Schier, Dr. E. Herdtweck, Professor Dr. W. Hiller and Professor Dr. F.E. Hahn (FU, Berlin) for structure refinements and discussions. H.H.K. thanks the Deutsche Forschungsge-meinschaft and the Fonds der Chemischen Industrie for financial support.
PY - 1997/2/15
Y1 - 1997/2/15
N2 - The reactions of ECl3 (E = P, As, Sb, Bi), RPCl2 (R = Me, Ph, 1Bu, Cy2N) and Ph2PCl, respectively, with ambident lithium phosphinomethanides are described. The reaction with LiCH2PMe2, 1, by E-C bond formation, leads to the substitution products E(CH2PMe2)3, 2a-d, (E = P, As, Sb, Bi) and R-P(CH2PMe2)2 (R = Me, Ph, 1Bu, Cy2N) 5a-d. In contrast, LiC(PMe2)(SiMe3)2 -0.5TMEDA, 6, gives substitution products with ECl3 (E = P, As, Sb), by E-P bond formation. Thus, the first element-tris(P-ylide)derivatives E(PMe2=C(SiMe3)2)3, 7a-c, are obtained. 7b is characterized by X-ray structure determination. In these reactions, oxidative P-P coupling to give [(Me3Si)2C=PMe2]2, 8, is also observed, and exclusively in the reaction of BiCl3 with 6. The reaction of RPCl2 (R = Me, Ph, 1Bu, Cy2N) with 6 strongly is dependent on the nature of R. For R = Me, only substitution is observed, yielding Me-P(PMe2=C(SiMe3)2)2, 10, while for R = Ph, both substitution and Li/Cl exchange with subsequent formation of 8 and the diphosphane [(Me3Si)2C=PMe2-PPh]2, 12, are found. The latter has been characterized structurally. In contrast, for R = 1Bu, only (1BuP)3, 13, and (1BuP)4, 14, are obtained. An analogous result is observed in the reaction of 1BuPCl2 with LiC(PMe2)2(SiMe3), 17. The reaction of Cy2NPCl2 with two equivalents of LiC(PMe2)(SiMe3)2 · 0.5TMEDA, 6, gives a phospha-alkene Cy2N-P=C(SiMe3)2, 16, and the substitution product Cy2N-P(PMe2=C(SiMe3)2)2, 15. Likewise, LiC(PMe2)2(SiMe3), 17, reacts with PhPCl2 to give the substitution product Ph-P(PMe2=C(PMe2)(SiMe3))2, 18, which is characterized by X-ray structure determination, whereas with MePCl2 only the P-ylide Me2P-PMe2=C(PMe2)(SiMe3), 20, and the coupling product [(Me2P)(Me3Si)C=PMe2]2, 19, are formed. The latter is also obtained in the reactions of BiCl3 or SbCl3 with LiC(PMe2)2(SiMe3), 17. Analogous redox reactions with AsCl3 and PCl3, respectively, lead to the bis-pentacyclic {μ-[C(PMe2)2(SiMe3)]As2}2, 21, and the hexacycle P-PMe2-C(SiMe3)-PMe2-C(SiMe3)-PMe2, 22, which were structurally characterized by X-ray analyses. Depending on the reaction conditions, the reaction of PCl3 with LiC(PMe2)2(SiMe3), 17, alternatively may lead to the triphosphete P-PMe2-C(SiMe3)-PMe2, 24. By using P-phenyl-substituents instead of P-methyl-substituents, i.e. in the reaction of LiC(PPh2)2(SiMe3), 25, with PCl3 or AsCl3, the triphosphete P-PPh2-C(SiMe3)-PPh2, 26a, or its arsenic analogue As-PPh2-C(SiMe3)-PPh2, 26b, are respectively formed, along with the chlorine substituted ylide (Cl)(Ph)2P=C(PPh2)(SiMe3), 27. 26a,b are characterized by X-ray structure determinations. The synthesis of the first ten-electron phosphorus cation P[C(PPh2)2(SiMe3)]+2, 30, with a homonuclear, spirocyclic PP4-framework was achieved by reacting the triphosphete 26a with the ylide 27 in the presence of NaBPh4. The crystal structure of the cation of 30, which adopts a Ψ-tbp geometry, was determined.
AB - The reactions of ECl3 (E = P, As, Sb, Bi), RPCl2 (R = Me, Ph, 1Bu, Cy2N) and Ph2PCl, respectively, with ambident lithium phosphinomethanides are described. The reaction with LiCH2PMe2, 1, by E-C bond formation, leads to the substitution products E(CH2PMe2)3, 2a-d, (E = P, As, Sb, Bi) and R-P(CH2PMe2)2 (R = Me, Ph, 1Bu, Cy2N) 5a-d. In contrast, LiC(PMe2)(SiMe3)2 -0.5TMEDA, 6, gives substitution products with ECl3 (E = P, As, Sb), by E-P bond formation. Thus, the first element-tris(P-ylide)derivatives E(PMe2=C(SiMe3)2)3, 7a-c, are obtained. 7b is characterized by X-ray structure determination. In these reactions, oxidative P-P coupling to give [(Me3Si)2C=PMe2]2, 8, is also observed, and exclusively in the reaction of BiCl3 with 6. The reaction of RPCl2 (R = Me, Ph, 1Bu, Cy2N) with 6 strongly is dependent on the nature of R. For R = Me, only substitution is observed, yielding Me-P(PMe2=C(SiMe3)2)2, 10, while for R = Ph, both substitution and Li/Cl exchange with subsequent formation of 8 and the diphosphane [(Me3Si)2C=PMe2-PPh]2, 12, are found. The latter has been characterized structurally. In contrast, for R = 1Bu, only (1BuP)3, 13, and (1BuP)4, 14, are obtained. An analogous result is observed in the reaction of 1BuPCl2 with LiC(PMe2)2(SiMe3), 17. The reaction of Cy2NPCl2 with two equivalents of LiC(PMe2)(SiMe3)2 · 0.5TMEDA, 6, gives a phospha-alkene Cy2N-P=C(SiMe3)2, 16, and the substitution product Cy2N-P(PMe2=C(SiMe3)2)2, 15. Likewise, LiC(PMe2)2(SiMe3), 17, reacts with PhPCl2 to give the substitution product Ph-P(PMe2=C(PMe2)(SiMe3))2, 18, which is characterized by X-ray structure determination, whereas with MePCl2 only the P-ylide Me2P-PMe2=C(PMe2)(SiMe3), 20, and the coupling product [(Me2P)(Me3Si)C=PMe2]2, 19, are formed. The latter is also obtained in the reactions of BiCl3 or SbCl3 with LiC(PMe2)2(SiMe3), 17. Analogous redox reactions with AsCl3 and PCl3, respectively, lead to the bis-pentacyclic {μ-[C(PMe2)2(SiMe3)]As2}2, 21, and the hexacycle P-PMe2-C(SiMe3)-PMe2-C(SiMe3)-PMe2, 22, which were structurally characterized by X-ray analyses. Depending on the reaction conditions, the reaction of PCl3 with LiC(PMe2)2(SiMe3), 17, alternatively may lead to the triphosphete P-PMe2-C(SiMe3)-PMe2, 24. By using P-phenyl-substituents instead of P-methyl-substituents, i.e. in the reaction of LiC(PPh2)2(SiMe3), 25, with PCl3 or AsCl3, the triphosphete P-PPh2-C(SiMe3)-PPh2, 26a, or its arsenic analogue As-PPh2-C(SiMe3)-PPh2, 26b, are respectively formed, along with the chlorine substituted ylide (Cl)(Ph)2P=C(PPh2)(SiMe3), 27. 26a,b are characterized by X-ray structure determinations. The synthesis of the first ten-electron phosphorus cation P[C(PPh2)2(SiMe3)]+2, 30, with a homonuclear, spirocyclic PP4-framework was achieved by reacting the triphosphete 26a with the ylide 27 in the presence of NaBPh4. The crystal structure of the cation of 30, which adopts a Ψ-tbp geometry, was determined.
KW - Group 15
KW - Heterocycles
KW - P-P bond formation
KW - Phosphinomethanides
KW - Phosphorus ylides
KW - Redox reactions
UR - http://www.scopus.com/inward/record.url?scp=0031568721&partnerID=8YFLogxK
U2 - 10.1016/S0022-328X(96)06578-3
DO - 10.1016/S0022-328X(96)06578-3
M3 - Article
AN - SCOPUS:0031568721
SN - 0022-328X
VL - 529
SP - 151
EP - 169
JO - Journal of Organometallic Chemistry
JF - Journal of Organometallic Chemistry
IS - 1-2
ER -