Yong‐Shou Lin, A. Yamamoto
Jul 9, 1998
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0
Influential Citations
62
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Journal
Organometallics
Abstract
Benzylpalladium and (phenylacetyl)palladium complexes having two PMe3 or PPh3 ligands or a dppe ligand (P2-type complexes) have been prepared as models to study the mechanisms of carbonylation reactions to convert benzyl halides into single and double carbonylation products. Removal of one of the tertiary phosphine ligands in the P2-type monophosphine complexes, trans-PdCl(COCH2Ph)(PR3)2 (R = Ph, Me), by treatment with PdCl2(PhCN)2 led to the P1-type chloride-bridged dimers [PdCl(COCH2Ph)(PR3)]2, which were split on interaction with secondary amines to give amine-coordinated complexes, PdCl(COCH2Ph)(PR3)(NHEt2). Examination of the reactions of the (phenylacetyl)palladium complexes with secondary amines and alcohols provided evidence for operation of different types of mechanisms for yielding amides and esters. The amide formation proceeds faster when more basic secondary amine is used. The process is proposed to proceed through coordination of the amine to palladium followed by its nucleophilic attack on ...