Übergangsmetall-substituierte Acylphosphane und Phosphaalkene, XIX / Transition Metal Substituted Acylphosphanes and Phosphaalkenes, XIX

Abstract

Phosphaalkenes, Metallo-l,2-dihydrophosphetes, X-Ray The metallo-phosphaalkenes (/75-C5Me5)(CO)2M -P = C (N R 2)2 (4a,b, 5) result from the reac tion of the corresponding bromo compounds (/75-C5Me5)(CO)2MBr with Me3Si-P = C (N R 2)2. The complexes 4a and 5a are cleanly converted into the l-metallo-l,2-dihydrophosphetes (//5-C5Me5)(CO)2M -PCH(E)-C(E) = C -NM e2 (lO a -c) (M = Fe, Ru; E = C 0 2Me, CN) by treatment with equimolar amounts of dimethyl fumarate or fumarodinitrile, respectively. The products 4a,b, 5 and lO a -c have been characterized by elemental analysis as well as by spec troscopic data (IR, 'H, 13C, 3IP NM R, MS). The molecular structures o f 4a and 10a have been determined by single crystal X-ray analysis.

Metal-Assisted Cycloaddition Reactions in Organotransition Metal Chemistry

“…Thermally, at 80°C, they are both converted to the same σ-butadienyl complex 38, the structure of which has again been elucidated by a single-crystal X-ray study. 125 The expected metallophosphetanes 49, however, are not isolated, but instead the 1-metallo-1,2-dihydrophosphetes 50, resulting from spontaneous elimination of dimethylamine.…”

Synthesis and Coordination Chemistry of Cyano-Substituted Phosphines

“…The result of the interaction is defined by the distribution of electron density in starting P-substrates. Thus in the reaction of Cp*(CO)2FeP=C(NMe2)2 151a having the reverse distribution of -electrons (P -=C + ) with fumaric acid dinitriles the formation of the P-metallated 1,2-dihydrophosphethene 153 accompanied by dimethylamine elimination was observed [127]. The similar process proceeded in the case of dimethylfumarate and in both cases the predictable [2+2] cycloaddition products 152 even were not detected in reaction mixtures by the NMR technique.…”

“…The other possibility of modification of a ligand in iron complexes comprises the interaction of ferrophosphaalkenes Cp*(CO)2FeP=CR2 with fumaric acid dinitriles [127,128]. The result of the interaction is defined by the distribution of electron density in starting P-substrates.…”

Reactivity of Ferriophosphaalkene [(η5-C5Me5)(CO)2Fe–P=C(NMe2)2] and Ferrioarsaalkene [(η5-C5Me5)(CO)2Fe–As=C(NMe2)2] Towards Trimethylaluminium, -gallium and -indium

“…During the course of our investigations on the chemical properties of metallophospha-and metalloarsaalkenes [(η 5 -C 5 Me 5 )(CO) 2 FeEϭC(NMe 2 ) 2 ] (E ϭ P, As) [1] [2] we have studied their reactivity towards transition metal carbonyls. Whereas the treatment of the arsalkene with [Ni(CO) 4 ], [Fe 2 (CO) 9 ] or [(Z)-cyclooctene)Cr(CO) 5 4 ], [Cr(CO) 5 ]) [3] the corresponding phosphaalkene and [Fe 2 (CO) 9 ] or [(Z)-cyclooctene)Cr(CO) 5 ] gave rise to the formation of complexes I and II.…”

“…[4] With nickel carbonyl adduct III was obtained. [4] Moreover, the metallophosphaalkene was converted by [(η 5 -C 5 H 5 )(CO) 2 Rh] into a complex analogous to II ([(η 5 -C 5 H 5 )(CO)Rh] instead of [Cr(CO) 5 ]) the arsaalkene was disintegrated to the η 2 -diarsene complex [{(η 5 -C 5 Me 5 )(C-O) 2 Fe-As} 2 Rh(CO)(η 5 -C 5 H 5 )]. [5] In view of these results it was obvious to extent our studies on the reactivity of the title compounds to electrophiles derived from main group metals.…”