2,2′-Bipyridyl formation from 2-arylpyridines through bimetallic diyttrium intermediate

Abstract

Formation of dianionic 2,2′-bipyridyl-bridged dinuclear yttrium complexes proceeded upon treatment of (ArNCH2CH2NAr)Y(CH2SiMe3)(THF)2 with 2-arylpyridine, in which mononuclear (2-pyridylphenyl)yttrium complexes were detected as key intermediates.

Structural and Synthetic Insights into Pyridine Homocouplings Mediated by a β‐Diketiminato Magnesium Amide Complex

“…[21] Interestingly,D iaconescu has shown that group 3b enzylc omplexess upported by af errocene bis(amide) ligand deliver dihydrobipyridyl complexes when reactedw ith 2-phenylpyridine, although harsh reaction conditions are required (3 days at 70 8C). [22] Related Zr II [23] and Y III [24] mediated pyridine homocouplingsh ave also been recently reported in the literatureb yt he groupso fG adea nd Mashima, respectively.…”

Building C(sp3) Molecular Complexity on 2,2′‐Bipyridine and 1,10‐Phenanthroline in Rhenium Tricarbonyl Complexes

“…AC 2-C2' interpyridyl ring distance of 1.414 in 2,s ignificantly contracted from that in the cation of 1 (1.477 ), suggested as tronger bond, and is closert ot hose reported for two-electron reduced bipy ligands( 1.396 (10) when coordinated to yttrium). [21] NICS values of À1.5 for the substituted ring, ando fÀ3.8 for the non-substitutedr ing of 2 stand in sharp contrast with the À8.9 value found for both rings of [Re(bipy)(CO) 3 (PMe 3 )] + .T hese resultsi ndicateastrong disruption of the aromaticity of both pyridyl rings in the bipy ligand of 1 upon addition of tBuLi.…”

Dehydrogenative Coupling of 4-Substituted Pyridines Catalyzed by a Trinuclear Complex of Ruthenium and Cobalt

“…The extraction of the generated bipyridine ligand is only reported by Mashima and co-workers upon treatment of the diyttrium complex bearing a μ-bipyridine ligand with CCl 4 . 4 We previously reported that di-and triruthenium complexes (Cp*Ru) 2 (μ-H) 4 (4) and (Cp*Ru) 3 (μ-H) 3 (μ 3 -H) 2 (5) (Cp* = η 5 -C 5 Me 5 ) catalyze the dimerization of several kinds of 4-substituted pyridines without the use of a sacrificial oxidant or hydrogen acceptor. 9 In contrast to the reactions performed using heterogeneous catalysts, these reactions selectively produced 2,2′-bipyridines without the formation of terpyridine.…”

“…Mashima and co-workers reported the coupling reaction of 2-arylpyridines using a diyttrium complex bearing a diamido ligand. 4 Riera and Peŕez reported the formation of unsymmetrical 2,2′-bipyridine ligands via the cross-coupling reaction of the two pyridine ligands on a Re complex. 5 Coupling reactions between two pyridine ligands via direct C−H bond cleavage using Sc, 6 Ta, 7 and Ru 8 complexes have also been reported.…”

“…Although examples are limited, the stoichiometric formation of 2,2′-bipyridines using a transition-metal complex is known. Mashima and co-workers reported the coupling reaction of 2-arylpyridines using a diyttrium complex bearing a diamido ligand . Riera and Pérez reported the formation of unsymmetrical 2,2′-bipyridine ligands via the cross-coupling reaction of the two pyridine ligands on a Re complex .…”