Cycloaddition Reactions of the Metal Phosphorus Double Bonded Complexes CP(CO)2M=PR2 (M = MO,W; R = Alkyl,Aryl)

Abstract

The reaction of the metal phosphorus double bonded species Cp(CO)₂M=PR₂ (M = Mo, W; R = aryl, alkyl) (1)¹⁾ with diverse diazoalkanes, alkenes, alkines and dienes results in the facile formation of the [2+1]-, [2+2]1- and [2+4]-cycloaddition products 2a-c.     

Über die Reaktionen von CH2=P(NMe2)3 mit Fe(CO)5, Cr(CO)6 und CS2; Molekülstrukturen von [MeP(NMe2)3][(CO)5CrC(O)CH=P(NMe2)3] und (CO)4Fe=C(OMe)CH=P(NMe2)3

The Reactions of CH₂=P(NMe₂)₃ with Fe(CO)₅, Cr(CO)₆, and CS₂; Molecular Structures of [MeP(NMe₂)₃][(CO)₅CrC(O)CH=P(NMe₂)₃], and (CO)₄Fe=C(OMe)CH=P(NMe₂)₃ The ylide CH₂=P(NMe₂)₃ ( 1 ) reacts with several binary transition metal carbonyls M(CO)_x to produce the corresponding salt like compounds [MeP(NMe₂)₃][(CO)_x–1MC(O)CH=P(NMe₂)₃] (M = Fe ( 3 ), Cr ( 4 )). The related reaction with CS₂ leads to the salt [MeP(NMe₂)₃][SC(S)CH=P(NMe₂)₃] ( 2 ). While 4 is thermally stable, 3 rapidly decomposes at room temperature with formation of [MeP(NMe₂)₃]₂[Fe₂(CO)₈] ( 8 ). Alkylation of 3 (at –50 °C) and 4 with MeSO₃CF₃ produces the related carbene complexes (CO)_x–1M=C(OMe)CH=P(NMe₂)₃ ( 5 ) and ( 6 ); the reaction of 3 with Me₃SiCl results in the formation of the carbene complex (CO)₄Fe=C(OSiMe₃)CH=P(NMe₂)₃ ( 7 ). 4 crystallizes in the space group P2₁2₁2₁ (No. 19) with a = 1111.1(2), b = 1476.1(3), c = 1823.1(4) pm and Z = 4. 5 crystallizes in the space group P2₁/n (No. 14) with a = 1303.6(3), b = 910.5(4), c = 1627.0(4) pm, β = 96.06(2)° and Z = 4. The compounds have been characterized by elemental analyses, NMR (¹H, ¹³C, ³¹P) and IR spectroscopy.     

Spectroscopic detection and theoretical confirmation of the role of Cr2(CO)5(C5R5)2 and .Cr(CO)2(ketene)(C5R5) as intermediates in carbonylation of N=N=CHSiMe3 to O=C=CHSiMe3 by .Cr(CO)3(C5R5) (R = H, CH3)

Conversion of N=N=CHSiMe3 to O=C=CHSiMe3 by the radical complexes .Cr(CO)3C5R5 (R = H, CH3) derived from dissociation of [Cr(CO)3(C5R5)]2 have been investigated under CO, Ar, and N2 atmospheres. Under an Ar or N2 atmosphere the reaction is stoichiometric and produces the Cr[triple bond]Cr triply bonded complex [Cr(CO)2(C5R5)]2. Under a CO atmosphere regeneration of [Cr(CO)3(C5R5)]2 (R = H, CH3) occurs competitively and conversion of diazo to ketene occurs catalytically as well as stoichiometrically. Two key intermediates in the reaction, .Cr(CO)2(ketene)(C5R5) and Cr2(CO)5(C5R5)2 have been detected spectroscopically. The complex .Cr(13CO)2(O=13C=CHSiMe3)(C5Me5) has been studied by electron spin resonance spectroscopy in toluene solution: g(iso) = 2.007; A(53Cr) = 125 MHz; A(13CO) = 22.5 MHz; A(O=13C=CHSiMe3) = 12.0 MHz. The complex Cr2(CO)5(C5H5)2, generated in situ, does not show a signal in its 1H NMR and reacts relatively slowly with CO. It is proposed to be a ground-state triplet in keeping with predictions based on high level density functional theory (DFT) studies. Computed vibrational frequencies are also in good agreement with experimental data. The rates of CO loss from 3Cr2(CO)5(C5H5)2 producing 1[Cr(CO)2(C5H5)]2 and CO addition to 3Cr2(CO)5(C5H5)2 producing 1[Cr(CO)3(C5H5)]2 have been measured by kinetics and show DeltaH approximately equal 23 kcal mol(-1) for both processes. Enthalpies of reduction by Na/Hg under CO atmosphere of [Cr(CO)n(C5H5)]2 (n = 2,3) have been measured by solution calorimetry and provide data for estimation of the Cr[triple bond]Cr bond strength in [Cr(CO)2(C5H5)]2 as 72 kcal mol(-1). The complex [Cr(CO)2(C5H5)]2 does not readily undergo 13CO exchange at room temperature or 50 degrees C implying that 3Cr2(CO)5(C5H5)2 is not readily accessed from the thermodynamically stable complex [Cr(CO)2(C5H5)]2. A detailed mechanism for metalloradical based conversion of diazo and CO to ketene and N2 is proposed on the basis of a combination of experimental and theoretical data.     

Über den Phosphandiyl‐Transfer von invers‐polarisierten Phosphaalkenen R1P=C(NMe2)2 (R1 = tBu,Cy, Ph,H) auf Phospheniumkomplexe [(η5‐C5H5)(CO)2M=P(R2)R3] (R2 = R3 = Ph; R2 = tBu,R3 = H; R2 = Ph,R3 = N(SiMe3)2)

Phosphanediyl Transfer from Inversely Polarized Phosphaalkenes R¹P=C(NMe₂)₂ (R¹ = tBu, Cy, Ph, H) onto Phosphenium Complexes [(η⁵‐C₅H₅)(CO)₂M=P(R²)R³] (R² = R³ = Ph; R² = tBu, R³ = H; R² = Ph, R³ = N(SiMe₃)₂) Reaction of the freshly prepared phosphenium tungsten complex [(η⁵‐C₅H₅)(CO)₂W=PPh₂] ( 3 ) with the inversely polarized phosphaalkenes RP=C(NMe₂)₂ ( 1 ) ( a : R = tBu; b : Cy; c : Ph) led to the η²‐diphosphanyl complexes ( 9a‐c ) which were isolated by column chromatography as yellow crystals in 24‐30 % yield. Similarly, phosphenium complexes [(η⁵‐C₅H₅)(CO)₂M=P(H)tBu] (M = W ( 6 ); Mo ( 8 )) were converted into (M = W ( 11 ); Mo ( 12 )) by the formal abstraction of the phosphanediyl [PtBu] from 1a . Treatment of [(η⁵‐C₅H₅)(CO)₂W=P(Ph)N(SiMe₃)₂] ( 4 ) with HP=C(NMe₂)₂ ( 1d ) gave rise to the formation of yellow crystalline ( 10 ). The products were characterized by elemental analyses and spectra (IR, ¹H, ¹³C‐, ³¹P‐NMR, MS). The molecular structure of compound 10 was elucidated by an X‐ray diffraction analysis.     

Synthesis of the New Silanediyldiphosphinite tBu2Si(OPPh2)2 and its Reactions with the Norbornadiene Complexes C7H8M(CO)4 (M = Cr,Mo, W). Crystal Structures of cis-M(CO)4[tBu2Si(OPPh2)2] (M = Cr,Mo)

Silanediyldiphosphinite tBu₂Si(OPPh₂)₂ 1 has been synthesised. 1 reacts with the norbornadiene complexes C₇H₈M(CO)₄ (M = Cr, Mo, W) to give six-membered chelate rings of the type cis-M(CO)₄[tBu₂Si(OPPh₂)₂] 2–4 . The crystal structures of the chromium and molybdenum complexes cis-Cr(CO)₄[tBu₂Si(OPPh₂)₂] 2 and cis-Mo(CO)₄[tBu₂Si(OPPh₂)₂] 3 have been determined. Both complexes crystallise in the triclinic system (space group P1 ) with unit cell parameters: ( 2 ) a = 1 093(3) pm, b = 1 477(5) pm and c = 1 542(5) pm; α = 108.4(2)°, b? = 103.87(11)° and b? = 104.57(10)°; U = 2.143(12) nm³; Z = 2; ( 3 ) a = 1 097.8(2) pm, b = 1 483.7(2) pm and c = 1 554.3(2) pm; α = 108.10(1)°, b? = 103.956(6)° and γ = 104.213(7)°; U = 2.1899(6) nm³; Z = 2. Both 2 and 3 consist of discrete, slightly distorted, octahedral monomers in which the six-membered chelate rings are essentially planar. In contrast, the conformations of the chelate rings found in crystal structures of analogous complexes vary from twist-boat to “chaise longue”.     

Umsetzung von C(NMe2)4 mit Ni(CO)4 – Synthesen und Strukturen von [C(NMe2)3][(CO)3NiC(O)NMe2], [C(NMe2)3]2[Ni5(CO)12] und [C(NMe2)3]3[Ni6(CO)12][O2CNMe2]

Reaction of C(NMe₂)₄ with Ni(CO)₄ – Syntheses and Structures of [C(NMe₂)₃][(CO)₃NiC(O)NMe₂], [C(NMe₂)₃]₂[Ni₅(CO)₁₂], and [C(NMe₂)₃]₃[Ni₆(CO)₁₂][O₂CNMe₂] The reaction of C(NMe₂)₄ with Ni(CO)₄ in THF produces the carbamoyl complex [C(NMe₂)₃][(CO)₃NiC(O)NMe₂] ( 1 ); side products are the purple cluster compound [C(NMe₂)₃]₂[Ni₅(CO)₁₂] · THF ( 2 · THF) and the red cocristallization product [C(NMe₂)₃]₃[Ni₆(CO)₁₂][O₂CNMe₂] ( 3 ). All compounds were studied by X‐ray diffraction analyses. The cations of 3 are all disordered but not those of 1 and 2 . The unit cell of 1 contains two crystallographically independent anions (I and II) which differ in the dihedral angle between the plane of the carbamoyl ligand and the plane defined by the atoms C_Carbamoyl–Ni–CO amounting 0° in the anion I and 18° in the anion II.     

Phosphorus(III)-Nitrogen-Sulphur Compounds: Synthesis and Metal Complexes

Abstract

The preparation and X-ray structure (M=Mo) of complexes of the type M(CO)₅(Ph₂PNSO) (M=Cr,Mo) are described. These complexes are used in the synthesis of homo- and hetero-dinuclear complexes of Ph₂PNSNPPh₂. A ³¹P DNMR study of these dinuclear complexes indicates a cis, trans → trans, cis isomerization in solution. The preparation and X-ray structure (M=Cr) of the mononuclear complexes, cis-M(CO)₄(P(Ph)₂NSN(Ph)₂P), (M=Cr,Mo) are also described.     

Fluxional behavior of (CO)4Fe(u-AsMe2)Mo(CO)2(C5H5)

The ¹H and ¹³C NMR spectra of the heterobimetallic compound (CO)₄Fe(μ-AsMe₂)Mo(CO)₂(C₅H₅) reveal three different fluxional processes.     

Syntheses and Reactions of Rhenium Carbamoyl Complexes of the Type (CO)4Re(NH2R)(CONHR) (R = Ethyl,Allyl or Isopropyl)

Carbamoyl complexes, (CO)₄Re(NH₂R)(CONHR)(R = ethyl, 1; R = allyl, 2; R = isopropyl, 3) were prepared by reactions of (CO)₅ReBr (or (CO)₅ReCH₂SiMe₃) with appropriate amines. Complexes 1, 2 and 3 reacted with CH₃CH₂COCl to give Re(CO)₅(NH₂R)⁺Cl^? (R = ethyl, 4; R = allyl, 5; R - isopropyl, 6). Complex 5 undergoes nucleophilic attack by KOMe to give the alkoxycarbonyl complexes (CO)₄Re(NH₂-Allyl)(COOMe), 7. Complexes 4, 5, 6 and 7 were transformed to the corresponding carbamoyl complexes by reacting with appropriate amines. The reactions between the carbamoyl complexes and R″OH/CHCl₃ in air at room temperature gave the proposed products [(CO)₄Re(NH₂R)]₂O (R = allyl, 8; R = isopropyl, 9), respectively. Complex 8 can also be prepared by heating 7 in CDCl₃ at 63–68°C for several days. The structure of 1 was confirmed by a X-ray crystallographic study. Crystallographic data: space group P2₁/c, a = 8.193 (3) Å, b = 19.273 (3) Å, c = 9.348 (8) Å, β = 110.37 (4)°, V = 1383.68 ų, Z = 4; R(F) = 0.027, R_w(F) = 0.030, based on 1888 reflections with I > 2.5σ(I). The other complexes were characterized by ¹H NMR, ¹³CNMR, IR and mass spectra.     

Synthesis and Reactions of the Novel Diphosphine,iPrN = C[CH2P(NiPr2)2]2

Abstract

The aldimine nBuN=CHiPr and phosphorus trichloride react to give phosphorus(III) amides in a 1:1 and 2:1 molar ratio. An imine-enamine tautomerism is proposed. In a [4+1] cycloaddition reaction diacetyl-(N-n-butyl)diimine and λ³σ³P-species, RPCl₂ or EtOPCl₂, form 1,2,3λ⁵σ⁴ -diazaphospholenes¹. The same diimine and (Et₂N)₂ PCl is furnishing annellated azaphospholenes¹. A 1,3,4λ⁵ σ⁴ -diazaphospholanium is formed from a λ³σ³ -phosphenium and iPrN=CMe₂ ². Phosphorus(III) amides P(NR₂)₃ (R= Me, Et) and O-trimethylsilylated diacetyldioxime give rise to yield the first monocyclic pentaazaphosphoranes.     

Metallsubstituierte Phosphaalkene und Acylphosphane. 31. Zur Reaktivität von (η5-C5Me5)(CO)2FeP = C(NMe2)2 gegenüber Zinndichlorid. Röntgenstrukturanalyse von {(η5-C5Me5)[η1-(Me2N)2C = P?P = C(NMe2)2](CO)2Fe}+{[Me2N)2C]2P}+(FeCl4)2−

Transition-Metal Substituted Phosphaalkenes and Acyl Phosphanes. 31 [1] Reactivity of (η⁵-C₅Me₅)(CO)₂FeP = C(NMe₂)₂ towards Tin Dichloride. X-Ray Structure Analysis of {(η⁵-C₅Me₅)[η¹-(Me₂N)₂C = P? P = C(NMe₂)₂](CO)₂Fe}⁺{[Me₂N)₂C]₂P}⁺(FeCl₄)^2? Reaction of metallophosphaalkene (η⁵-C₅Me₅)(CO)₂ · FeP = C(NMe₂)₂ ( 1 ) with anhydrous tin dichloride affords the salt-like compound {(η⁵-C₅Me₅)[η¹-(Me₂N)₂C = P? P = C(NMe₂)₂] · (CO)₂Fe}⁺{[(Me₂N)₂C]₂P}⁺(FeCl₄)^2? 5 which is characterized by single crystal X-ray analysis and spectra (IR, ¹H, ³¹P-NMR).