Metallorganische Lewis‐Säuren, IL. Bis(acyl)1‐verbrückte heterometallische Komplexe von Rhenium, Molybdän, Ruthenium und Kupfer

Abstract

Organometallic Lewis Acids, IL[1]. – Bis(acyl)1‐Bridged Heterometallic Complexes of Rhenium, Molybdenum, Ruthenium, and Copper The reaction of the metalla‐β1‐diketonate complex [(OC)41‐Re[–C(Me)O]2][NMe4] with various organometallic Lewis acids yields the bis(acyl)1‐bridged bimetallic complexes (OC)4 ‐Re[–C(Me)O–]2Re(CO)4 (1), (OC)4Re[–C(Me)O–]2MoCp(CO)2 (2), (OC)4Re[–C(Me)O–]2Ru(η31‐C3 H5)(nbd) (nbdnorbor‐nadiene) (3), [(OC)4 Re[–C(Me)O–]2Ru(PPh3)2 (CO)2][BF4] (4), and (OC)4 Re[–C(Me)O–]2Cu[–O(Me)C–]2Re(CO)4 (5), respectively. The structures of the compounds 1–5 have been determined by X‐ray diffraction. They show different conformations of the six‐membered ring Re[–C(Me)O–]2[M]. The molecular structure of complex 1 proves a “flipping” of the acyl ligands.

Binuclear Aroyl and Carbamoyl Complexes of Iron: X-ray Crystal Structures of [Fe2(μ:σ,σ‘-OCR)2(CO)5(PPh3)] (R = C6H3Me2-2,6, NiPr2)

“…This latter contribution is supported by the molecular stasis revealed by NMR spectroscopy. Each of these requires an Fe−Fe bond to complete the EAN requirements of each metal in contrast, for example, to the “rhenadiketonates” described by Lukehart which have no apparent direct intermetallic interaction across a planar six-membered bimetallacycle which approaches planarity 3 Resonance contributors for the Fe 2 (μ-OCR) 2 cores of 1 and 2 . 4 Comparison of the Geometries of the Metallacycles in 1 and 2 parameterR = C 6 H 3 Me 2 -2,6 ( 1 )R = N i Pr 2 ( 2 ) a (Å) 1.988(6), 1.954(5) 1.993(3), 2.013(3) b (Å) 1.243(6), 1.245(6) 1.270(4), 1.274(4) c (Å) 1.966(4), 1.996(4) 1.977(2), 1.956(2) d (Å) 2.590(1) 2.569(1) α (deg) 93 90 …”

Reactivity of ortho-β-Enaminone-phenyl Palladium Complexes. Insertion of CO into the Pd−C Bond to Give the First Acyl C,N,O-Pincer Complexes. Sequential Insertion of Dimethylacetylenedicarboxylate into the Enaminone C−H Bond and of Isocyanide into the Pd−C Bond. A New Photooxigenation/Cyclization Process

“…Among the many acyl complexes of Pd previously known, some of them reported by us, ,,,,,, none bears, as 3 , a symmetric double acyl bridge. Of the few similar isolated complexes (Al, Ga, Re, , Ru, or Ir), six X-ray crystal structures have been reported, only three of them corresponding to benzoyl derivatives…”

Low-valent Organorhenium Compounds

“…224 The metalla-|3-diketonate complexes o f the type [Re(COMe) 2 (CO) 4 ][NMe 4 ] undergo reaction with organometallic Lewis acids to give bis(acyl)bridged bimetallic complexes such as (116). 225 The rhenaacetylacetone complex [Re(CMeOHO-CMe)(CO) 4 ] undergoes condensation reactions with a variety of amino acid esters to give rhena-pketoimine complexes (117). 226 229 Enolate (119) undergoes reaction with metal carbonyl electrophiles to give u-malonyl complexes (e.g., (120), (121)), or a u-ketene complex (122), depending on the specific nature of the electrophile (Scheme 27).…”