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

Abstract

Palladium(II) acetate reacts with proline and proline homologs in acetone/water to yield square planar bis-chelated palladium amino acid complexes. These compounds are all catalytically active with respect to oxidative coupling of olefins and phenylboronic acids. Some enantioselectivity is observed and formation of products not reported in other Pd(II) oxidative couplings is seen. The crystal structures of nine catalyst complexes were obtained. Extended lattice structures arise from N-H••O or O••(HOH)••O hydrogen bonding. NMR, HRMS, and single-crystal XRD data obtained on all are evaluated.

Role of additives and solvents in the synthesis of chiral isoreticular MOF-74 topologies

“…A particularity of this complex relates to the presence of two ν OH red shifted at 3303 and 3340 cm −1 due to the hydrogen bonding interactions established between the hydroxyl group and the carbonyl of adjacent ligand molecules or to a water molecule as in the case of [Pd( l -Hyp) 2 ]·3H 2 O. 38 Additional hydrogen bonding of the water to another carboxylate oxygen supports the two ν OH red shifted bands. The decomposition of the complex is observed between 370–530 °C, with the corresponding exothermic effect on the DSC curve at ca.…”

Synthesis, Characterization, and Non-Covalent Interactions of Palladium(II)-Amino Acid Complexes

“…Molecules 2021, 26, 4331 For complex (4), the isobutyl group has similar steric demands to the isopropyl group and the H-bonding network in its crystal lattice is quite different from complex (2). Again, a lattice water molecule serves as an H-bond donor to a non-bonded carboxylate oxygen, but there is no analogous H-bond acceptor role from an N-H bond.…”

“…Prior work from our group has dealt with the simplest α amino acids, the glycines [ 1 ], and the cyclic amino acids, the prolines [ 2 ], respectively. In this paper, we will explore the synthesis, characterization, and non-covalent interactions of the palladium(II) complexes of the remaining naturally occurring amino acids.…”

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

“…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.…”