Transformation of Manganese Acyls (CO)₅MnC(O)CH₂R (R = H, CH₃, OCH₃) into Their Siloxyvinyl Derivatives (CO)₅MnC(OSiEt₃)CHR with Triethylsilane. An Approach to Double Carbonylation of Manganese Alkyl Complexes (CO)₅MnCH₂R

Abstract

Treatment of the manganese acyl complexes (CO)5MnC(O)CH2R [R = H (1a), CH3 (1b), OCH3 (1c)] with triethylsilane gave stable α-triethylsiloxyvinyl compounds (Z)-(CO)5MnC(OSiEt3)CHR (3a − c). Carbonylation of 3a and 3b, followed by protonolysis of the resulting (CO)5MnC(O)C(OSiEt3)CHR [R = H (5a), CH3 (5b)] provided their α-ketoacyl derivatives (CO)5MnC(O)C(O)CH2R (6a and 6b), which represents a net double carbonylation of their alkyl precursors (CO)5MnCH2R.

Phosphine Addition to Pyruvoyl Ligands of Iron Complexes: Formation of Zwitterionic Metallalactones

“…To appraise the involvement of such entities in the course of these reactions, the synthesis and the study of stable complexes of Pt, Mn, Co, or Fe bearing one or two carbonylated ligands have been performed . Although sequential double migratory insertion of carbon monoxide into a [M]−R bond affording a [M]C(O)C(O)R linkage is only found to occur under very specific conditions, − the possible intervention of α,β-dicarbonylated groups in multiple carbonylation processes has however been considered. It has been found that complexes containing a single [M]C(O)C(O)R chain can be thermally decarbonylated, giving rise to the corresponding [M]C(O)R compound ([M] = Mn(CO) 5 and R = CH 3 , Ph; [M] = trans -Pd or Pt(PPh 3 ) 2 Cl and R = Ph; [M] = trans -[Pt(PPh 3 ) 2 (CO)] + and R = Ph).…”

The acylation of an acyl complex resulting in a labile OCO tridentate ligand

“…It constitutes a rare case 6 of an acyl group being modified while the C-M sbond is maintained. Such a transformation can activate an acyl to further carbonylation reaction 7 and constitutes an approach to a double carbonylation of alkyl complexes. In the field of catalytic reactions promoted by ruthenium carbonyls, the hydrogenation of carbon monoxide to C 2 products in anhydrous acetic acid 8 Notes and references † Compound 1 2 (6.92 g, 16.6 mmol) was suspended, under an argon atmosphere, in 50 ml of anhydrous propionic acid containing 14 ml (108 mmol) of propionic anhydride.…”