Carbonyl‐Monoolefin‐Derivate des Chroms, Molybdäns und Wolframs. I. Tetracarbonyl‐Phosphin‐Olefin‐Komplexe

Abstract

Monoolefin‐Komplexe cis‐M(CO)4(PR3)(olefin) (M  Cr, Mo, W; R  Et, Bu, Pri, Ph; olefin  Maleinsäureanhydrid, Dimethylmaleat, Dimethylfumarat, Bis(trimethylsilyl)fumarat, Ethylen) sind aus den ionischen Verbindungen Et4N[R3PM(CO)4Cl] entweder über Ethanol‐ oder Acetonitrilderivate M(CO)4(PR3)L oder direkt im Zweiphasensystem zugänglich. Die Olefine werden von Lewis‐Basen wie Aminen oder Phosphinen unter milden Bedingungen substituiert.

π-Complexes of Chromium, Molybdenum and Tungsten, Excluding those of Cyclopentadienyls and Arenes

“…Similarly, 17-electron [Cr(r| 3 -C 3 H 5 ) 2 Cp] reacts with L (L = CO, PMe 3 or P(OMe) 3 ) to give r| ,T| 2 -hexadiene products (16) and with butadiene to form (17); 65 6 ] with MgBr(allyl) 68 and an improved synthesis of [Mo(r| 3 -C 3 H 5 ) 4 ] starting from MoCl 4 -2THF and MgCl(allyl) has also been described. 69 71 The analogous chemistry of the tungsten-alkyl complexes has also been developed, 68 In principle, the allyl-bridged dimers [M 2 (r| 3 -allyl) 4 ] may exhibit nine isomeric forms with respect to configurations of terminal and bridging allyl ligands but, in solution, [M 2 (T| 3 -C 3 H 5 ) 4 ] (M = Cr or Mo) exists as an isomeric mixture of (18) and (19) in the ratio (18) (19). 66 In the case of [Cr 2 (r| 3 -C 3 H 5 ) 4 ] these exchange processes have been corroborated by two-dimensional dynamic 1 3 C NMR spectroscopy.…”