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Strong circularly polarized luminescence (CPL) at 1550 nm is reported for lanthanide complexes supported by Vanol; these are the first examples of coordination of Vanol to lanthanides. A change in the ligand design from a 1,1’‐bi‐2‐naphthol (in Binol) to a 2,2’‐bi‐1‐naphthol (in Vanol) results in significantly improved dissymmetry factors for (Vanol)₃ErNa₃(|g_lum|=0.64) at 1550 nm. This is among the highest reported dissymmetry factors to date in the telecom C‐band region, and among the highest for any lanthanide complexes. Comparative solid‐state structural analysis of (Vanol)₃ErNa₃and (Binol)₃ErNa₃suggests that a less distorted geometry around the metal center is in part responsible for the high chiroptical metrics of (Vanol)₃ErNa₃. This phenomenon was further evidenced in the analogous ytterbium complex (Vanol)₃YbNa₃that also exhibit a significantly improved dissymmetry factor (|g_lum|=0.21). This confirms and generalizes the same observation that was made in other visibly emitting, six‐coordinate lanthanide complexes. Due to their strong CPL at 1550 nm, the reported complexes are potential candidates for applications in quantum communication technologies. More importantly, our structure‐CPL activity relationship study provides guidance towards the generation of even better near‐infrared CPL emitters.

 

We describe the synthesis of C 2 -symmetrical enantiopure lanthanide complexes (Tb, Eu, Sm, Dy) supported by the decadentate ligand N , N , N ′, N ′-tetrakis[(6-carboxypyridin-2-yl)methyl]-1,2-diaminocyclohexane (tpadac). The chiral tpadac ligand was designed to protect the lanthanide center from coordination of inner-sphere water molecules resulting in air- and water-stable, and highly luminescent complexes in water. The complexes exhibit strong chiroptical properties, with high dissymmetry factors g lum (0.11 to 0.25) and CPL brightness B CPL (up to 245 M −1 cm −1 for Tb, λ exc 295 nm, λ em 544 nm) in water. These are the first example of aqueous Sm CPL and second example of aqueous Dy CPL reported to date. The lanthanide complexes obtained gave a reversible CPL response to pH ranging from 6.0 to 8.0. In addition, distinctive CPL responses (including a change in CPL sign) towards toxic cations (Pb 2+ , Cd 2+ , and Mn 2+ ) were also observed, demonstrating the potential of our complexes to be used as aqueous probes. 

The cleavage of alkyl ethers by hydrosilylation is a powerful synthetic tool for the generation of silyl ethers. Previous attempts to apply this transformation to carbohydrate derivatives have been constrained by poor selectivity and preferential reduction of the anomeric position. O -Aryl glycosides are found to be stable under iridium- and borane-catalyzed hydrosilylation conditions, allowing for alkyl ether cleavage without loss of anomeric functionality. A cationic bis(phosphine)iridium complex catalyzes the selective 3-demethylation of a variety of 2,3,4-tri- O -methyl pyranoses, offering a unique approach to 3-hydroxy or 3-acetyl 2,4-di- O -methylpyranoses. 

Abstract The field of catalytic C–H borylation has grown considerably since its founding, providing a means for the preparation of synthetically versatile organoborane products. Although sp2 C–H borylation methods have found widespread and practical use in organic synthesis, the analogous sp3 C–H borylation reaction remains challenging and has seen limited application. Existing catalysts are often hindered by incomplete consumption of the diboron reagent, poor functional-group tolerance, harsh reaction conditions, and the need for excess or neat substrate. These challenges acutely affect the C–H borylation chemistry of unactivated hydrocarbon substrates, which has lagged in comparison to methods for the C–H borylation of activated compounds. Herein, we discuss recent advances in the sp3 C–H borylation of undirected substrates in the context of two particular challenges: (1) utilization of the diboron reagent and (2) the need for excess or neat substrate. Our recent work on the application of dipyridylarylmethane ligands in sp3 C–H borylation has allowed us to make contributions in this space and has presented an additional ligand scaffold to supplement traditional phenanthroline ligands.