Efficient Modular Synthesis of Isomeric Mono‐ and Bispyridyl[2.2]paracyclophanes by Palladium‐Catalyzed Cross‐ Coupling Reactions

Abstract

Pyridyl-substituted [2.2]paracyclophanes build am ultifunctional structural motif that is useful in material chemistry,c atalysis and for luminescent structures.N onetheless,t here is still al ack of general methodsf or the synthesiso ft hese structures tolerating easily accessiblebromides as well as different isomeric pyridyl groups.H ence the coupling of functionalized [2.2]paracyclophanes with various substituted andf unctionalized pyridyl derivatives was ach-ieved using Stille,S uzuki andK umada coupling conditions.H ereby the Stille coupling of a [2.2]paracyclophane is presenteda saversatile reaction for the formation of heteromeric [2.2]paracyclophane-containing biaryl structures.

[2.2]Paracyclophanes with N‐Heterocycles as Ligands for Mono‐ and Dinuclear Ruthenium(II) Complexes

“…In order to develop [2.2]paracyclophanes as bridging ligands, we synthesized the different mono‐ and homodisubstituted [2.2]paracyclophanes. As previously shown, pyridyl substituents are easily accessible through Stille cross‐coupling reactions in only one step (Scheme ) . This makes these substituents attractive as they can be easily varied with respect to subsequent fine‐tuning of this ligand type.…”

“…In case of the bispyridyl‐substituted 13 (Figure ), the molecule shows the characteristic twist between the pyridyl rings and the [2.2]paracyclophane backbone, which was reported for the mono‐ and pseudo‐ para ‐disubstituted [2.2]paracyclophanes . It is noteworthy that with 32.3° and 44.1° two different angles were observed for the twist of the two pyridyl substituents towards the [2.2]paracyclophane backbone, whereas for the pseudo‐ para ‐derivative 6 a they show the same angle of 37.2° …”

“…The molecular structure of 21 b for one of the two independent molecules per unit cell is shown in Figure . The observed conformations of the bispyridyl‐ and bispyrimidyl‐substituted [2.2]paracyclophanes can be explained by minimization of the dipoles and packing effects in the solid state.…”

Synthesis and Characterization of a Ruthenium(II) Complex for the Development of Supramolecular Photocatalysts Containing Multidentate Coordination Spheres

“…Chlorinated phenanthroline 3 suitable for Stille reaction was obtained by treatment of the corresponding dione 2 with PCl 5 and POCl 3 following literature‐known procedures . The stannylated pyridine was obtained by a lithium–bromine exchange reaction and consecutive introduction of the stannyl moiety at the 2‐position of the pyridine . The synthesized precursors 2,9‐dichloro‐1,10‐phenanthroline ( 3 ) and 2‐(tributylstannyl)pyridine were subjected to Stille coupling conditions by using tetrakis(triphenylphosphine)palladium(0) [Pd(PPh 3 ) 4 ] as catalyst and dry toluene as solvent in order to obtain ligand 4 .…”

Unprecedented One‐Pot Reaction towards Chiral, Non‐Racemic Copper(I) Complexes of [2.2]Paracyclophane‐Based P,N‐Ligands

“…Nevertheless, apart from PhanePhos, there are only few examples for bidentate, pseudo‐ ortho ‐disubstituted [2.2]paracyclophane‐based ligands. Therefore we aimed to synthesize the pseudo‐ ortho ‐bispyridyl[2.2]paracyclophane 6 as an alternative for a bidentate N , N ‐ligand using our elaborated Stille cross‐coupling protocol for pyridyl‐substituted [2.2]paracyclophanes from the pseudo‐ ortho ‐dibromide 8 .…”