Superresolution fluorescence microscopy of multiple fluorophores still requires development. Here we present simultaneous three-colour stimulated emission depletion (STED) nanoscopy relying on a single STED beam at 620 nm. Toggling the STED beam between two or more power levels (“multilevelSTED”) optimizes resolution and contrast in all colour channels, which are intrinsically co-aligned and well separated. Three-colour recording is demonstrated by imaging the nanoscale cytoskeletal organization in cultured hippocampal neurons. The down to ~35 nm resolution identified periodic actin/betaII spectrin lattices along dendrites and spines; however, at presynaptic and postsynaptic sites, these patterns were found to be absent. Both our multicolour scheme and the 620 nm STED line should be attractive for routine STED microscopy applications.

As ynthetic protocol for the preparation of 5-(aryl)dibenzothiophenium salts starting from inexpensive dibenzothiophene S-oxide and simple arenes is reported. The scope of the method regarding the nature of the arene is evaluated, intermediates along the reaction sequence have been trapped, and side-reactions identified. In addition, the X-ray structures of acomplete set of these salts are reported and their reactivities studied. Specifically,c hemoselective Suzuki coupling is observed at the dibenzothiophenium in the presence of iodides.

1‐Aminopyrenes with three ω‐hydroxylated N‐alkylsulfonamido or alkylsulfonyl residues in positions 3, 6, and 8 were prepared, O‐phosphorylated, and applied for reductive amination of oligosaccharides. The dyes (ϵ≈20 000 m−1 cm−1) with six negative charges (pH≥8) and low m/z ratios enable labeling and fluorescence detection of reducing sugars (glycans) related to the most structurally and functionally diverse class of natural products. Under excitation with a 488 nm laser, the new glycoconjugates emit yellow light of about 560 nm, outperforming (with respect to brightness and faster electrophoretic mobilities) the corresponding APTS derivatives (benchmark dye with green emission in conjugates).

This article reports the efficient preparation of a series of unsymmetrically substituted thioethers through a two‐step procedure consisting of an initial metal‐free C−H sulfenylation of electron‐rich (hetero)arenes with newly prepared succinylthioimidazolium salts. Subsequent reaction of the arylthioimidazolium intermediates with Grignard reagents afford the desired thioethers. The synthetic protocol described is modular, scalable, and high yielding, and provides access to sulfides that are not easy to obtain through the existing methodologies. Importantly, no prefunctionalization of the initial (hetero)arene is required.

A synthetic protocol for the preparation of 5‐(aryl)dibenzothiophenium salts starting from inexpensive dibenzothiophene S‐oxide and simple arenes is reported. The scope of the method regarding the nature of the arene is evaluated, intermediates along the reaction sequence have been trapped, and side‐reactions identified. In addition, the X‐ray structures of a complete set of these salts are reported and their reactivities studied. Specifically, chemoselective Suzuki coupling is observed at the dibenzothiophenium in the presence of iodides.

1‐Aminopyrene mit drei ω‐hydroxylierten N‐ Alkylsulfonamido‐ oder Alkylsulfonylgruppen an C‐3, C‐6 und C‐8 wurden hergestellt, O‐phosphoryliert und in der reduktiven Aminierung von Oligosacchariden eingesetzt. Diese Farbstoffe (ϵ≈20 000 m−1 cm−1) mit sechs negativen Ladungen (pH≥8) und niedrigen m/z‐Werten ermöglichen die Markierung, Elektrophorese und Detektion von reduzierenden Zuckern (Glykanen), welche die strukturell und funktionell vielfältigste Klasse von Naturprodukten darstellen. Bei Anregung mit einem 488‐nm‐Laser emittieren die neuen Glykokonjugate gelbes Licht von etwa 560 nm und weisen bessere Helligkeit und höhere elektrophoretische Mobilität als die entsprechenden APTS‐Derivate (Referenz mit grüner Emission) auf.

The C 3 -symmetrical molecule, tris(4-methoxyphenyl)stibine, C 21 H 21 O 3 Sb, crystallizes with one third of the molecule in the asymmetric unit. Bond lengths and angles of the Sb-C bonds lie in between those of the isostructural homologues C 21 H 21 O 3 Bi and C 21 H 21 O 3 As. The formation of dimers via six weak C-HÁ Á Á interactions is considered. Structure descriptionThe title compound, C 21 H 21 O 3 Sb, exhibits perfect C 3 -symmetry with one third of the molecule in the asymmetric unit. To our surprise, the structure of the title compound (Fig. 1) is not reported in the database (CSD; Groom et al., 2016), although we regularly observe it as a side product in our synthesis of asymmetric sulfides (Bö hm et al., 2018). To fill the gap in the row of homologues of the type C 21 H 21 O 3 E, with E being an element of group 14, the title compound is reported herein. It is isostructural with the homologues C 21 H 21 O 3 Bi (Hé bert et al., 2016) and C 21 H 21 O 3 As (Sobolev & Belsky, 1981). The lighter homologue C 21 H 21 O 3 P (Allman et al. , 1986;Bruckmann et al., 1995) crystallizes in the space group P2 1 /c while the lightest homologue C 21 H 21 O 3 N is, so far, not known in the CSD. The Sb-C bond distance and C-Sb-C angle observed here, 2.148 (2) Å and 95.8 (1) , lie between those of the neighbouring isostructural As and Bi homologues. However, the Sb-C bond distance is closer to that of the Bi derivative with the Bi-C distances being 0.103 Å longer, and the As-C distance 0.175 Å shorter, than that observed for the title compound. No strong intermolecular interactions were observed, Fig. 2. The distances between the C1-C6 centroid and atoms C5 or C3 of the next molecules [3.814 (2) and 3.849 (2) Å , respectively] indicate weak C-HÁ Á Á interactions, Table 1 and Fig. 3. It is noteworthy that two molecules are connected by six of these weak C-HÁ Á Á interactions via C3, forming discrete dimeric units with the antimony atom facing outwards.

reactivity of succinylthioimidazolium salts: A unified strategy for the preparation of thioethers Dissertation zur Erlangung des mathematisch-naturwissenschaftlichen Doktorgrades "Doctor rerum naturalium" der Georg-August-