Bis-glycinato complexes of palladium(II): Synthesis, structural determination, and hydrogen bonding interactions

Synthesis, Structure, and Catalytic Reactivity of Pd(II) Complexes of Proline and Proline Homologs

“…The 1 H NMR data show the expected ratios of integrated resonances, and the 13 C NMR spectrum shows possible evidence of aquo complex formation. As seen with the glycine complexes [69] discussed in a prior paper, the carbon NMR data for 6 shows two peaks for each carbon. The HRMS is as expected for a palladium complex.…”

“…The resultant complex formed with this ligand is trans bis-(N-methylprolinato) palladium(II) ( Figure 5), confirmed by X-ray crystallographic analysis. As with the glycine complexes, replacement of the amine hydrogen atom with a methyl group results in a degree of steric crowding that disfavors formation of the cis isomer [69]. All attempts to As with the glycine complexes, replacement of the amine hydrogen atom with a methyl group results in a degree of steric crowding that disfavors formation of the cis isomer [69].…”

“…In earlier work, we showed that the amino acid complexes of rhodium and iridium piano stools were useful for asymmetric hydrogenation [68]. We have previously reported on the simpler glycine complexes [69], and these proline and proline homologs represent another unique subset of amino acid ligands where the R-group of the amino acid is a cyclic ring moiety. Subsequent papers will discuss our work with beta-amino acid complexes and amino acids where the R-group is a linear substituent.…”

Self-Assembly Motifs of Water in Crystals of Palladium β-Amino Acid Complexes Influenced by Methyl Substitution on the Amino Acid Backbone

“…Three different, readily available β-amino acids were examined: 3-aminopropanoic acid, (S)-3-aminobutanoic acid and 3-amino-3-methylbutanoic acid. Syntheses of the palladium compounds were straightforward and the procedures followed those we have reported on previously [35]. In terms of isomer formation, 3-aminopropanoic acid gave exclusively the trans isomer, trans-bis(3-aminopropanoate) palladium, compound 1.…”

“…Recently, we have been investigating the structures and catalytic properties of amino acid complexes of palladium. We have published a paper on glycine and substituted glycines [35] as well as a paper on palladium complexes of proline and proline homologs [36]. A common and consistent feature of all complexes is their propensity for hydrogen bonding-with the carbonyl oxygen acting as H-bond acceptor and the NH 2 hydrogens acting as H-bond donors.…”