Organic syntheses by means of noble metal compounds. XXXIV. Carbonylation and decarbonylation reactions catalyzed by palladium

Palladium‐Catalyzed Transformation of Renewable Oils into Diesel Components

“…The XPS experiments confirmed the conclusion that palladium(0) provided active sites for the decarboxylation of renewable oils, although PdCl 2 showed a high catalytic activity for decarbonylation of acyl chlorides. [18] With methyl palmitate as a model compound, we found that the selectivity of decarboxylates was a time-independent but temperature-dependent parameter (see Supporting Information, Figure S6). Selectivity of decarboxylates was maintained above 98% as the reaction proceeded, while on an increase of the reaction temperature, the proportion of decarboxylates raised.…”

First Observation of Alkali Metal Ion Induced Trans–Cis Isomerization of Palladium(II) Phosphane Complexes Containing Crown Ether Moieties

“…[5] The identities of 1-4 have been confirmed by 1 H, 13 C{ 1 H}, and 31 P{ 1 H} NMR spectroscopic analysis, positive-ion FAB mass spectrometry, and satisfactory elemental analyses. The crystal structures of 1 and 2 have also been established as having a trans configuration by X-ray crystallographic analysis.…”

“…The reaction of [PdX 2 (PhCN) 2 ] with two equivalents of PPh 2 -benzo[15]-crown-5 (PPh 2 (B15C5)) or PPh 2 -benzo[18]crown-6 (PPh 2 (B18C6)) in benzene, by using a modification of literature procedures, [5] produced [PdX 2 -{PPh 2 (B15C5)} 2 ] (X= Cl, 1; [6] Br, 2; I, 3) and [PdCl 2 -{PPh 2 (B18C6)} 2 ] (4). [5] The identities of 1-4 have been confirmed by 1 H, 13 C{ 1 H}, and 31 P{ 1 H} NMR spectroscopic analysis, positive-ion FAB mass spectrometry, and satisfactory elemental analyses.…”

Intermolecular Hydroacylation by Transition‐Metal Complexes

“…In order to facilitate this reaction, the aldehydic C-H bond can be cleaved with transition metals to form an acyl metal hydride 1, followed by the insertion of the hydride into an unsaturated C-C bond to generate acylmetal alkyl complex 2 (Scheme 1). [10][11][12][13][14] Reductive elimination of the acylmetal alkyl 2 affords ketone 3 with the regeneration of the transition metal as catalyst. Scheme 1. One of the important side-reactions of the hydroacylation process is decarbonylation.…”

“…Subsequent hydride insertion into the coordinating alkene of stable acylmetallacyclic complex 10 forms sixmembered acylmetallacyclic complex 11. Finally reductive elimination from the metallacyclic intermediate 11 affords cyclopentanone (12). This intramolecular hydroacylation process can be applied to the synthesis of cyclopentanone derivatives from 4-pentenal derivatives although some substrate variations allow the synthetic scope to be extended to other cycloalkanones.…”