Two Schiff Base Ligands Derived from 1,2-Diaminocyclohexane

Cannadine, Jason C.; Corden, J. P.; Errington, William; Moore, Peter R.; Wallbridge, M. G. H.

doi:10.1107/s0108270195014090

Cited by 9 publications

(3 citation statements)

References 1 publication

(1 reference statement)

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“…[16] The X-ray structures obtained from these described compounds showed a centroid-centroid distance of 7.20 and 6.51 Å, respectively, but the angle formed between the planes of the two aromatic rings is 83.13°for the first substrate and 56.46°for the second. These very open angles are probably the reason [17] why compounds 6a and 6b do not seem to give molecular assemblies with 2a ( Table 2, Entries 1 and 2).…”

Section: Synthesis Of New Molecular Tweezers From (1r2r)-12-cyclohementioning

confidence: 98%

Molecular Tweezers: Synthesis and Formation of Host–Guest Complexes

et al. 2010

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A chiral molecular tweezer obtained from (+)‐usnic acid placed in solution in the presence of various aromatic compounds afforded complexes with low association constants. Thus, the X‐ray structure of assembly 3i is presented, where the guest is sandwiched between the two pincers of the tweezer. The association constants for various guests were determined through different methods. Finally, other tweezers with electron‐rich aromatic aldehydes and ketones were prepared from (1R,2R)‐1,2‐diaminocyclohexane. The most interesting complexes were also confirmed through structural analysis, and the best results were obtained with 10‐hydroxyphenanthrene‐9‐carbaldehyde (5i) as the aromatic moiety.

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Section: Synthesis Of New Molecular Tweezers From (1r2r)-12-cyclohementioning

confidence: 98%

Molecular Tweezers: Synthesis and Formation of Host–Guest Complexes

et al. 2010

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“…Trianglimines (18)(19)(20)(21) were reduced by sodium borohydride (NaBH 4 ) in a mixture of THF and MeOH to the corresponding trianglamines (26)(27)(28)(29) in excellent yields without needing further purification (Fig. 13).…”

Section: Conformational Analysis For the Non-symmetrical Trianglimine...mentioning

confidence: 99%

Synthesis of tri-substituted biaryl based trianglimines: formation of C3-symmetrical and non-symmetrical regioisomers

et al. 2011

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2-Functionalised aromatic monoaldehydes were synthesised in good to excellent yields by reacting 4-bromo-2-fluorobenzaldehyde with different secondary amines and phenol. The Suzuki-coupling reaction of the newly functionalised aromatic monoaldehydes with 4-formylphenylboronic acid afforded the corresponding 2-functionalised-4,4'-biphenyldialdehydes in good yields (47-85%). The [3+3]-cyclocondensation reactions of the 2-functionalised-4,4'-biphenyldialdehydes with (1R,2R)-1,2-diaminocyclohexane afforded a mixture of regioisomeric C(3)-symmetrical and non-symmetrical trianglimines. Reduction of the C(3)-symmetrical and the non-symmetrical trianglimines with NaBH(4) in a mixture of THF and MeOH afforded the corresponding trianglamines in high yields.

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“…Superposition of the structures of the salan ligand, meso (RS,SR)- N,N ’- bis (2-hydroxybenzyl)-1,2-diphenyl-1,2-diaminoethane [ 49 ] and its sulfonated product, dPhHSS ( 4 ) ( Figure 4 ) also shows high degree of similarity ( Figure S20 ) and proves that the starting salen underwent hydrogenation as well as sulfonation in the p- position relative to the phenolic oxygen. The major difference between the structures of 5b ( Figure 5 ) and its starting material for synthesis, i.e., (±)- trans -CyS [ 50 ] is in the position of the aromatic rings ( Figure S23 ). Perhaps the most important information is that, during the synthesis of cis -CyHSS × 2H 2 O ( 5ca ) ( Figure 5 ), the cis -conformation in the Schiff base formed in the reaction of salicylaldehyde and cis -1,2-diaminocyclohexane is retained throughout hydrogenation and sulfonation.…”

Section: Resultsmentioning

confidence: 99%

Palladium (II)–Salan Complexes as Catalysts for Suzuki–Miyaura C–C Cross-Coupling in Water and Air. Effect of the Various Bridging Units within the Diamine Moieties on the Catalytic Performance

et al. 2020

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Water-soluble salan ligands were synthesized by hydrogenation and subsequent sulfonation of salens (N,N’-bis(slicylidene)ethylenediamine and analogues) with various bridging units (linkers) connecting the nitrogen atoms. Pd (II) complexes were obtained in reactions of sulfosalans and [PdCl4]2−. Characterization of the ligands and complexes included extensive X-ray diffraction studies, too. The Pd (II) complexes proved highly active catalysts of the Suzuki–Miyaura reaction of aryl halides and arylboronic acid derivatives at 80 °C in water and air. A comparative study of the Pd (II)–sulfosalan catalysts showed that the catalytic activity largely increased with increasing linker length and with increasing steric congestion around the N donor atoms of the ligands; the highest specific activity was 40,000 (mol substrate) (mol catalyst × h)−1. The substrate scope was explored with the use of the two most active catalysts, containing 1,4-butylene and 1,2-diphenylethylene linkers, respectively.

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Two Schiff Base Ligands Derived from 1,2-Diaminocyclohexane

Cited by 9 publications

References 1 publication

Molecular Tweezers: Synthesis and Formation of Host–Guest Complexes

Molecular Tweezers: Synthesis and Formation of Host–Guest Complexes

Synthesis of tri-substituted biaryl based trianglimines: formation of C3-symmetrical and non-symmetrical regioisomers

Palladium (II)–Salan Complexes as Catalysts for Suzuki–Miyaura C–C Cross-Coupling in Water and Air. Effect of the Various Bridging Units within the Diamine Moieties on the Catalytic Performance

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