Reactivity of the Inversely Polarised Arsaalkenes R–As=C(NMe₂)₂ {R = [(η⁵‐C₅Me₅)(CO)₂Fe], tBuC(O)} Towards Vinylidene Complexes [η⁵‐(C₅H₅)(CO)(NO)W=C=C(H)R] (R = Ph, tBu)

Abstract

The reaction of the vinylidene complexes [(C5H5)(CO)(NO)W=C=C(H)R] (10a: R = tBu; 10b: R = Ph) with the arsaalkene tBuC(O)–As=C(NMe2)2 (11) afforded the novel η2‐1‐arsaallene complexes [η2‐{tBuC(O)–As=C=C(H)R}W(CO)(NO)C5H5] (13: R = tBu; 15: R = Ph). Similarly, treatment of 10a with the ferrioarsaalkene [(C5Me5)(CO)2Fe–As=C(NMe2)2] (12) led to the formation of [η2‐{[(C5Me5)(CO)2Fe]–As=C=C(H)tBu}W(CO)(NO)(C5H5)] (14), whereas combination of 12 and 10b yielded the carbene complex [(C5H5)(CO)(NO)W=C(NMe2)C(Ph)=C(H)NMe2] (16) in high yield instead of the anticipated arsaallene complex. The novel compounds 13, 14, 15 and 16 were characterised by elemental analyses and by means of spectroscopy (IR, 1H, 13C NMR). Moreover, the molecular structures of 14 and 15 were elucidated by X‐ray diffraction analyses. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006)

Synthesis of the η2‐1‐Phosphaallene Complexes [(η5‐C5H5)(CO)(NO)W{η2‐R1P=C=C(R2)H}] (R1 = tBu, Cy; R2 = Ph, H) from [(η5‐C5H5)(CO)(NO)W=C=C(R2)H] (R2 = Ph, H) and Inversely Polarized Phosphaalkenes R1P=C(NMe2)2 (R1 = tBu, Cy), and Their Structure

“…The air-and moisture-sensitive complexes 14 and 15 are well soluble in saturated hydrocarbon, ethereal, and aromatic solvents. Complex 16 has been generated previously by the treatment of 9 with [Cp*(CO) 2 -FeAs=C(NMe 2 ) 2 ] in 69 % yield, [7] and characterized by means of spectroscopy and elemental analyses. Similarly, yellow crystalline 17 resulted from the reaction of phosphaalkene 1a and vinylidene complex 12 [10] in a molar ratio of 1:2 in thf at 20°C (Scheme 7).…”

“…A similar observation was made in the molecular structure of 11b. [7] The W(1)-P(1) separation [2.568(1) Å] markedly exceeds the WP bond length in 19 [2.434(2) Å] and may be compared with the endocyclic WP bond lengths in complexes 21 [2.5352(7) and 2.5695(7) Å] [5] or 22 [2.573(4) and 2.582(4) Å]. [15] The endocyclic P(1)-C(2) bond length [1.742(4) Å] may be regarded as being a π-coordinated multiple bond.…”

“…This extension seemed particularly promising in light of the previous synthesis of η 2 -1-arsaallene complexes 11a-c from vinylidene complexes 9 and 10 and arsaalkenes (Scheme 4). [7] Moreover, Ipaktschi et al have succeeded in the transformation of vinylidene complex 12 into η 2 -allene complexes 13a-c by treating them with diazomethane and ethyl diazoacetate (Scheme 5). [8] In this contribution we present our results on the smooth phosphinidene transfer from phosphaalkenes 1a and 1c to the vinylidene ligands of complexes 9 and 12.…”

Phospha‐ and Arsaalkenes RE=C(NMe2)2 (E = P, As) as Novel Phosphinidene‐ and Arsinidene‐Transfer Reagents

“…Elemental arsenic and complex [Cp*Fe(CO) 2 ] 2 were also obtained (82 % yield). [78] The generation of carbene complex 123 was previously observed in the reaction of 120 with phosphaalkenes RP=C(NMe 2 ) 2 82 (a: R = tBu; b: Cy). [68] …”

“…Treatment of complex [Cp(CO)(NO)-W=C=C(H)(tBu)] (161) with an equimolar amount of arsaalkenes R-As=C(NMe 2 ) 2 {162: R = tBuC(O); 154: R = Cp*(CO) 2 Fe} in diethyl ether solution in the range -30°C to room temperature afforded the crystalline η 1 -1-arsaallene complexes 163 (50 % yield) and 164 (73 % yield), respectively after chromatography. Compound 164 was obtained as a mixture of two isomers [78] (Scheme 65). In sharp contrast to this, reaction of 120 with ferrioarsaalkene 154 did not lead to the anticipated arsaallene system.…”