Coordination-Driven Supramolecular Synthesis Based on Bimetallic Cu(I) Precursors: Adaptive Behavior and Luminescence.

Pre-organized adaptive Cu(I) bimetallic precursors can be successfully engaged in coordination-driven supramolecular reactions. Selective formation either of a large family of compact metallacycles or of polymetallic discrete assemblies and one-dimensional coordination polymers is rationalized taking into account the relative amplitudes of conformational flexibility allowed by the precursors used. It reveals the originality of the self-assembly processes conducted with such Cu(I)-based building blocks. In addition, exalted luminescence properties can be embedded in the resulting supramolecular assemblies due to the specific photophysical behaviors of Cu(I)-luminophores. General and straightforward access toward coordination-driven supramolecular assemblies featuring original architectures and multifunctional luminescence properties is therefore highlighted, taking advantage of both the specificities of the coordination chemistry and the electronic structure of derivatives based on the Cu(I) ion.

Gleaned snapshots on the road to coordination polymers: heterometallic architectures based on Cu(I) metallaclips and 2,2'-bis-dipyrrin metalloligands.

The assembly of binuclear Cu(i) metallaclips with 2,2'-bis-dipyrrin based metalloligands gives rise to a diversity of architectures featuring a recurring π-stacked compact tetranuclear metallacycle but differing in their nuclearity and dimensionality depending on the nature of the capping ligands and metal cations.

A solid state highly emissive Cu(i) metallacycle: promotion of cuprophilic interactions at the excited states.

The straightforward synthesis of a new Cu(i) metal-rich small metallacycle is presented. This compound is luminescent in the solid state with an emission quantum yield of 72% at room temperature and displays a pronounced reversible red-shift of its emission spectra upon cooling. Quantum chemical calculations reveal that these properties are governed by important geometrical relaxations that imply the formation of cuprophilic interactions at the excited states.

Correction: Supramolecular metallacycles with a 'pseudo double-paracyclophane' structure based on flexible π-conjugated linkers.

Correction for 'Supramolecular metallacycles with a 'pseudo double-paracyclophane' structure based on flexible π-conjugated linkers' by W. Shen et al., Chem. Commun., 2015, 51, 11560-11563.

Supramolecular metallacycles with a 'pseudo double-paracyclophane' structure based on flexible π-conjugated linkers.

The straightforward synthesis of new supramolecular metallacycles having a 'pseudo double-paracyclophane' structure is presented. They are obtained from the reaction of a pre-assembled Cu(I) bimetallic precursor bearing short intermetallic distances with cyano-capped homoditopic π-conjugated linkers having flexible central cores.

[MR-endoscopic US correlation for loco-regional staging of rectal carcinoma]. / Corrélation IRM-échoendoscopie dans le bilan d'extension locorégional initial du cancer du rectum.

INTRODUCTION: To correlate findings at high-resolution MR and endoscopic US (EUS) for preoperative loco-regional staging of rectal carcinoma. PATIENTS AND METHODS: Fifty-two patients with rectal carcinoma underwent high-resolution MR imaging. Only 43 of these patients underwent EUS due to technical limitations and stenosing carcinomas. Morphological imaging features and TNM staging were evaluated for both imaging modalities. The degree of correlation and accuracy were calculated for both. RESULTS: The correlation between MR and EUS was good for tumor length and thickness (r=0.7 and 0.61) for for nodal (N) staging (k=0.53). Correlation was good for T1 and T2 stages (k=0.51) and T3 stage (k=0.43) and very poor for stage 4 (k= -0.09), because no T4 lesion was detected at EUS. 81.8% of patients where T stage was over-estimated on MRI and 100% of patients where T stage was over-estimated on EUS had received preoperative radiation therapy. Therefore, results should be interpreted with caution. The predictive evaluation of tumor resectability (absence of perirectal fascia invasion) with a circumferential margin on MR> or =5 mm was 93%. CONCLUSION: Correlation between MR and EUS was moderate for T staging, because of limitations of EUS for large tumors. Results confirm that high-resolution MRI is useful for loco-regional staging of rectal carcinoma, especially for large tumors. EUS should be limited to the valuation of superficial tumors of the rectum.

A new synthesis of 2-azabicyclo[2.1.1]hexanes.

An efficient synthesis of the 2-azabicyclo[2.1.1]hexane ring system has been accomplished starting from cis-cyclobut-3-ene-1,2-dicarboxylic anhydride 7, which was prepared using a photochemical method. The key step of this new strategy involved a stereoselective electrophilic addition of phenylselenyl bromide to the double bond of cyclobutene dicarbamate 16 derived from 7. The subsequent ring closure of 17a in the presence of sodium hydride afforded the 2-azabicyclohexane compound 18 with a satisfying overall yield. Reductive removal of the phenylselenyl group and subsequent deprotection led rapidly to the amino derivative 4a functionalized on the carbon ring. Syntheses of the hydroxy and carboxylic derivatives 4b,c were then achieved from the intermediary disulfonamide 23. Displacement of the activated amino group by potassium acetate yielded hydroxy derivative 4b after three additional steps. Finally, oxidation of the alcohol function of 4b under Jones conditions followed by hydrogenolysis afforded the carboxylic derivative 4c, which is the first reported beta-isomer of 2,4-methanoproline 1.