Synthesis, structure, and catalytic activity of complexes of 1,1′-bisisoquinoline with PdCl2 and NiCl2

Abstract

New complexes of 1,1´ bisisoquinoline with PdCl 2 and NiCl 2 were synthesized. The struc tures of the complexes were established by X ray diffraction. The Pd II complex acts as a catalyst for the Suzuki and Heck reactions and the hydroarylation of norbornene. As exemplified by the Suzuki reaction, the Ni II complex can also be used as a catalyst.

1,1′-Biisoquinolines—Neglected Ligands in the Heterocyclic Diimine Family That Provoke Stereochemical Reflections

“…The bright green paramagnetic complex [Ni(biiq) 3 ] 2+ has been isolated from the reaction of biiq with [Ni(H 2 O) 6 ](ClO 4 ) 2 in EtOH [ 77 ]. In contrast, the reaction with NiCl 2 ·6H 2 O in n BuOH gives the structurally characterized compound [Ni(biiq) 2 Cl 2 ] (CSD Refcode BAFRUY, space group P 2 1 / c , N2–C1–C1′–N2′ torsion angles −40.11, 36.91°, Figure 15 a) which has been shown to be an effective catalyst for the Suzuki coupling reaction [ 143 ]. Each molecule contains one biiq ligand with the 1 M configuration and one with the 1 P configuration leading to the full description cis - rac -(Δ)-[Ni{{1 M )-biiq}{(1 P )-biiq}Cl 2 ] (remember that the metal is also a stereogenic center in an octahedral {M(N^N) 2 × 2 } species, where N^N is a chelating bidentate ligand).…”

“…Each molecule contains one biiq ligand with the 1 M configuration and one with the 1 P configuration leading to the full description cis - rac -(Δ)-[Ni{{1 M )-biiq}{(1 P )-biiq}Cl 2 ] (remember that the metal is also a stereogenic center in an octahedral {M(N^N) 2 × 2 } species, where N^N is a chelating bidentate ligand). The complex [Pd(biiq)Cl 2 ] has also been prepared and structurally characterized (CSD Refcode BAFSUZ, space group P 2 1 / c , N2–C1–C1′–N2′ torsion angles −22.48, 27.64°, Figure 15 b) and is effective as a catalyst in Suzuki and Heck reactions as well as in hydroxylation reactions [ 143 ]. The lattice of [Pd(biiq)Cl 2 ] contains equal numbers of crystallographically independent [Pd[(1 M )-biiq}Cl 2 ] and [Pd{(1 P )-biiq}Cl 2 ] molecules.…”

“…The compound exhibits a strong orange-red emission at 672 nm [142]. The related complex [Ir(15) 2 (biiq)](PF 6 ) (Figure 14) has been prepared and the photophysical properties as well as the solid-state structure reported (CSD Refcode REMQOQ, space group P1, N2-C1-C1 -N2 torsion angle −30.36 • , Figure 14 15a) which has been shown to be an effective catalyst for the Suzuki coupling reaction [143]. Each molecule contains one biiq ligand with the 1M configuration and one with the 1P configuration leading to the full description cis-rac-(∆)-[Ni{{1M)-biiq}{(1P)-biiq}Cl 2 ] (remember that the metal is also a stereogenic center in an octahedral {M(NˆN) 2 × 2 } species, where NˆN is a chelating bidentate ligand).…”

“…Each molecule contains one biiq ligand with the 1M configuration and one with the 1P configuration leading to the full description cis-rac-(∆)-[Ni{{1M)-biiq}{(1P)-biiq}Cl 2 ] (remember that the metal is also a stereogenic center in an octahedral {M(NˆN) 2 × 2 } species, where NˆN is a chelating bidentate ligand). The complex [Pd(biiq)Cl 2 ] has also been prepared and structurally characterized (CSD Refcode BAFSUZ, space group P2 1 /c, N2-C1-C1 -N2 torsion angles −22.48, 27.64 • , Figure 15b) and is effective as a catalyst in Suzuki and Heck reactions as well as in hydroxylation reactions [143] Electrospray and collision-induced dissociation MS studies of methanol solutions containing group 10 compounds and biiq have been reported [126]. The catalytic system [Pd(O 2 CCF 3 ) 2 ]-biiq has been shown experimentally to be moderately active in the reaction of 2,6-dimethoxybenzoic acid with MeCN to give 2,6-dimethoxyacetophenone; investigations at the DFT level were also reported [144].…”

The crystal structure of 1,1′-bisisoquinoline, C18H12N2

“…Optically active complexes with high chiral recognition can be formed by reaction of 1,1′-bisisoquinoline with chiral palladium complexes [16]. Pd(II) and Ni(II) complexes of 1,1′-bisisoquinolines can be used as catalysts for Suzuki and Heck reactions [17]. 1,1′-Bisisoquinolinium salts exhibit chemiluminescence on addition of hydrogen peroxide in alkaline solution [18].…”