Palladium salicylaldimine complexes containing boronate esters

Abstract

Reactions of salicylaldehydes with boronate ester derivatives of aniline have been examined. Addition of these Schiff base ligands to palladium acetate or Na 2 PdCl 4 afforded novel boron-containing trans-bis(N-arylsalicylaldiminato) palladium complexes.Condensation of salicylaldehyde (2-HOC 6 H 4 C(O)H) with H 2 NC 6 H 4 Bpin (pin ¼ 1,2-O 2 C 2 Me 4 ) afforded the boron-containing Schiff bases, 2-HOC 6 H 4 C(H)@NC 6 H 4 Bpin (1-3a). Similar reactivity with 2-hydroxy-5-nitrobenzaldehyde and 2-hydroxy-1-naphthaldehyde gave the corresponding Schiff bases (1-3b) and (1-3c), respectively. Reaction of Schiff bases (2) and (3) with palladium acetate or Na 2 PdCl 4 afforded complexes of the type PdL 2 (4,5), where L ¼ deprotonated Schiff base. The molecular structure of the nitro-salicylaldehyde 4-Bpin palladium complex (5b) was characterized by an X-ray diffraction study. All new palladium compounds have been characterized fully and tested for their antifungal activity against Aspergillus niger and Aspergillus flavus.

Pd(II) and Zn(II) Based Complexes with Schiff Base Ligands: Synthesis, Characterization, Luminescence, and Antibacterial and Catalytic Activities

“…The geometry at the Pd(II) center in 1 is square planar, with the two cyclometalated ligands in a trans arrangement. The Pd–O and Pd–N distances are 1.969(3) and 2.026(4) Å, similar to those seen in related complexes [ 4 , 17 ]. In the six-membered chelate rings, the six atoms (Pd1, O1, C1, C6, C7, N1) are essentially planar.…”

Synthesis and reactivity of new functionalized Pd(II) cyclometallated complexes with boronic esters

“…The Pd-C [1.968 (3) [20,19,[21][22][23]. The B-O and B-C distances are similar to previously reported values [12].…”

“…Although the synthesis and reactivity of boronic acids and esters is well studied, few complexes in which this group is part of a coordinated ligand are known [12][13][14].…”

Palladium(II) Pyridinecarboxaldimine Complexes Derived from Unsaturated Amines

“…Likewise, we have reported that bis(salicylaldiminato)palladium(II) complexes derived from aminoboron compounds display moderate antifungal activity against Aspergillus niger and A. flavus [44].…”