The Suzuki-Miyaura coupling reaction of electron-poor aryl chlorides in the synthesis of crop protection-relevant active ingredients in water is disclosed. Optimisation of the reaction conditions allowed to run the reaction...

Reported here is the Pd-catalyzed C-N coupling of hydrazine with (hetero)aryl chlorides and bromides to form aryl hydrazines with catalyst loadings as lowas100 ppm of Pd and KOHa sb ase.M echanistic studies revealed two catalyst resting states:a na rylpalladium(II) hydroxidea nd arylpalladium(II) chloride.T hese compounds are present in two interconnected catalytic cycles and react with hydrazine and base or hydrazine alone to give the product. The selectivity of the hydroxide complex with hydrazine to form aryl over diaryl hydrazine was lower than that of the chloride complex, as well as the catalytic reaction. In contrast, the selectivity of the chloride complex closely matched that of the catalytic reaction, indicating that the aryl hydrazine is derived from this complex. Kinetic studies showed that the coupling process occurs by rate-limiting deprotonation of ah ydrazine-bound arylpalladium(II) chloride complex to give an arylpalladium-(II) hydrazido complex.

The preparation of a functionalized 4H-benzo-[1,4]-oxazin-3-one was completed via a three-step nitration/hydrogenation/cyclization sequence. The unstable nature of the nitro and amino intermediates, in addition to the hazards associated with the nitration of organic compounds in general, makes this procedure exceedingly difficult to perform on industrial scale. To overcome these limitations, we have developed a fully integrated continuous protocol in which the aromatic starting material (2,2-difluoro-2-(3-fluorophenoxy)-N,N-dimethylacetamide) is subjected to an initial continuous flow dinitration using 20% oleum in combination with 100% HNO3 (2.5 equiv) using a microstructured device heated to 60 °C. This was followed directly by continuous flow hydrogenation of the dinitrointermediate over a Pd/C fixed bed catalyst at 45 °C. The resulting air-sensitive diamino derivative was then directly cyclized to the desired 6-amino-2,2,7-trifluoro-4H-benzo-[1,4]-oxazin-3-one target compound via an acid-catalyzed cyclization step at 80 °C using a tubular reactor. Uninterrupted continuous flow processing was achieved by integrating liquid–liquid membrane separation technology and the inline removal of excess of hydrogen gas using gas permeable tubing into the process. The overall product yield for the continuous flow process was 83%, a significant increase compared to yield reported for the batch process (67%).

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Expansion microscopy (ExM) enables super-resolution imaging of proteins and nucleic acids on conventional microscopes. However, imaging of details of the organization of lipid bilayers by light microscopy remains challenging. We introduce an azide-and amino-modified sphingolipid ceramide, which upon incorporation into membranes can be labeled by click chemistry and linked into hydrogels, followed by 4x to 10x expansion. Confocal and structured illumination microscopy (SIM) enabled imaging of sphingolipids and their interactions with proteins in the membrane of intracellular organelles with a spatial resolution of 10-20 nm. Because sphingolipids accumulated efficiently in pathogens we used sphingolipid ExM to investigate bacterial infections of human HeLa229 cells by Neisseria gonorrhoeae, Chlamydia trachomatis and Simkania negevensis with a resolution so far only provided by electron microscopy. In particular, sphingolipid ExM allowed us to visualize the inner and outer membrane of intracellular bacteria and determine their distance to 27.6 ± 7.7 nm. The Supporting Information is available free of charge on the ACS Publications website. Supplementary Figures S1-S23. Supplementary Movie 1: 10x ExM SIM z-stack of Hela229 cells infected with Chlamydia trachomatis for 24 h, fed with α-NH2-ω-N3-C6-ceramide, fixed, permeabilized and stained with DBCO-Alexa Fluor 488. Chlamydia are clearly located at the inclusion membrane. Scale bar, 10 µm.