Molecular Rotors:  Design, Synthesis, Structural Analysis, and Silver Complex of New [7.7]Cyclophanes

Bogdan, Niculina D.; Grosu, Ion; Benoît, Guillaume; Toupet, Loı̈c; Ramondenc, Yvan; Condamine, Eric; Silaghi‐Dumitrescu, Ioan; Plé, G.

doi:10.1021/ol0610845

Cited by 22 publications

(19 citation statements)

References 15 publications

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“…Derivatives with two 1,3-dioxane rings connected to the same aromatic ring were successfully used for the synthesis of macrocyclic cyclophanes [13,14]. In order to obtain versatile substrates for the synthesis of new "host" molecules (1,3,5-cyclophanes) we considered it of interest to carry out the synthesis, and investigate the stereochemistry and the preorganization [15] for macrocyclisation of derivatives bearing three 1,3-dioxane rings connected to the same aromatic substrate.…”

Section: Methodsmentioning

confidence: 99%

Synthesis and stereochemistry of some new 1,3,5-tris(1,3-dioxan-2-yl)-benzene derivatives

Florian¹,

Cîrcu

Toupet

et al. 2006

Open Chemistry

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Abstract:The synthesis and the stereochemistry of new 1,3,5-tris(1,3-dioxan-2-yl)-benzene derivatives are reported. The anancomeric structure and the axial orientation of the aryl group with respect to all 1,3-dioxane rings, and the cis-trans isomerism of some of the compounds are revealed. The data are supported by NMR investigations and by the molecular structure of one compound determined by single crystal X-ray diffractometry.

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Section: Methodsmentioning

confidence: 99%

Synthesis and stereochemistry of some new 1,3,5-tris(1,3-dioxan-2-yl)-benzene derivatives

Florian¹,

Cîrcu

Toupet

et al. 2006

Open Chemistry

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“…The first route has been previously used, e.g., for the formation of pydic ester complexes [{Cu(pydicR2)Cl}2(µ-Cl)2] (R = Me, Et, i Pr) [17,22] and consists of two subsequent steps, the synthesis of the pydicR2 ligand, and its isolation followed by the complex formation reaction (1). Pyridine-2,6-dicarboxylic alkyl-or arylester derivatives pydicR 2 coordinating to metal ions have been reported with R = methyl [15][16][17][18][19][20][21], ethyl [18,20,[22][23][24][25][26], iso-propyl [18], n-butyl [26], and benzyl [18], with further complexes containing related non-symmetric or macrocyclic esters RpydicR' [23,24,[27][28][29][30]. Aryl substituted systems are less frequent [27].…”

Section: Synthesis and Molecular Structures Of Pydicr2 Ligands And Thmentioning

confidence: 99%

Pyridine-2,6-Dicarboxylic Acid Esters (pydicR2) as O,N,O-Pincer Ligands in CuII Complexes

et al. 2019

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The pyridine-2,6-carboxylic esters pydicR2 with R = Me or Ph form the unprecedented mononuclear CuII complexes [Cu(pydicR2)Cl3]− in one-pot reactions starting from pyridine-2,6-carboxychloride pydicCl2, CuII chloride, and NEt3 in MeOH or PhOH solution under non-aqueous conditions. The triethylammonium salts (HNEt3)[Cu(pydicR2)Cl3] were isolated. The methyl derivative could be crystallized to allow a XRD structure determination. Both structures were optimized using DFT calculations in various surroundings ranging from gas phase and the non-coordinating solvent CH2Cl2 to the weakly coordinating acetone and well-coordinating solvents acetonitrile (MeCN) or dimethylformamide (DMF), while detailed calculation showed the charge distribution, dipole moments, and HOMO–LUMO gap energies changing upon solvation. According to these calculations, the ion pairs and the anionic CuII complexes were stable, which shows only Cu–Cl bond elongation and weakening of the charge transfer between the anionic complex and the cation as solvents become polar. Synthesis attempts in the presence of water yielded the CuII complexes [Cu(pydic)(OH2)2]n and [Cu(OH2)6][{Cu(pydic)}2(µ-Cl)2], which results from pydicCl2 hydrolysis. Alternatively, the new pydic(IPh)2 (IPh = 2-iodo-phenyl) ester ligand was synthesized and reacted with anhydrous CuCl2, which yields the new binuclear complex [{Cu(pydic(IPh)2)Cl}2(µ-Cl)2]. EPR spectroscopy of the solid compounds reveals typical axial spectra in line with the observed and DFT calculated geometries. Cyclic voltammetry and UV–vis absorption spectroscopy in solution are in line with un-dissociated complex species [Cu(pydicR2)Cl3]−.

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“…In contrast to shaft rotations with single axes, the integration of multiple rotational axes (that is, integral rotation) has also been examined. The aim is to obtain the dynamic “jump rope” motion of macrocyclic compounds having various rotational blade‐like moieties, such as 2,6‐pyridinocyclophane, [15] 2,5‐disilylthiophene derivatives, [16] cis ‐PtCl 2 (PR 3 ) 2 [17] and trans ‐bis(salicylaldiminato)Pd(II) [18] . Other work has examined the non‐unidirectional rotations of C−C, [19,22] C=C [20] and C=N [21] bonds, based on the chemically [19,22] and photochemically [20,21] driven rotations of triptycyl[4]helicenes, [19] 1,1’‐bi(cyclohexylidene)s, [20] dibenzosuberone imines [21] and biaryl lactones [22] as the key irreversible steps in multistep, rachet‐like rotatory processes.…”

Section: Introductionmentioning

confidence: 99%

Catalytic Enantioselective Rotation of Watermill‐Shaped Dinuclear Pd Complexes

et al. 2021

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The catalytic enantioselective rotation of double-paddled, watermill-shaped palladium complexes is described in this report. The achiral syn-and chiral anti-forms of binuclear transbis(salicylaldiminato)palladium(II) complexes doubly linked with polymethylene bridges (1) were synthesized and subsequently characterized by spectroscopic and single crystal XRD analyses. The heptamethylene-linked complex 1 b undergoes highly controllable rotation between the achiral syn and chiral antiforms at ambient temperature, while the hexamethylene-linked analogue 1 a does not exhibit this rotational motion under the same conditions, due to its shorter bridges, and 1 c (with octamethylene linkers) undergoes uncontrollable rapid rotation even at lower temperatures. The kinetics of the dynamic rotation of syn-1 b to the anti-isomer in solution were examined on the basis of 1 H NMR analyses. The data showed that the rotational rate can be greatly modified by varying the solvent or adding a carboxylic acid. The enantioselective rotation of syn-1 b can be induced using a catalytic amount of (2R,3R)-2,3bis(3,5-dimethylbenzoyl)tartaric acid (2 a) to afford (R)-anti-1 b, with an initial enantiomeric excess of 63 % ee and an equilibrium value of 27 % ee. Curve fitting of data for the parallel reversible transformations of syn-1 b to (R) and (S)-anti-1 b gave the forward and reverse first-order rate constants k 1 , k À 1 (for syn to (R)-anti), k 2 and k À 2 (syn-to (S)-anti), and verified that the enantioselective nature of the present catalytic enantioselective rotation is controlled kinetically during the initial stage (k 1 > k 2 ) and thermodynamically in the equilibrium state (k 1 /k À 1 > k 2 /k À 2 ). The specific changes induced in the transition states in response to the use of various solvents and adducts are discussed herein on the basis of the activation parameters for the rotation of syn-1 b, as determined from plots of the kinetic data as functions of time.

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Molecular Rotors: Design, Synthesis, Structural Analysis, and Silver Complex of New [7.7]Cyclophanes

Cited by 22 publications

References 15 publications

Synthesis and stereochemistry of some new 1,3,5-tris(1,3-dioxan-2-yl)-benzene derivatives

Synthesis and stereochemistry of some new 1,3,5-tris(1,3-dioxan-2-yl)-benzene derivatives

Pyridine-2,6-Dicarboxylic Acid Esters (pydicR2) as O,N,O-Pincer Ligands in CuII Complexes

Catalytic Enantioselective Rotation of Watermill‐Shaped Dinuclear Pd Complexes

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