Synthesis of Polyflourinated Biphenyls; Pushing the Boundaries of Suzuki–Miyaura Cross Coupling with Electron-Poor Substrates

Polyfluorinated biphenyls are interesting and promising substrates for many different applications. Unfortunately, all current methods for the syntheses of these compounds only work for a hand full of molecules or only in very special cases. Thus, many of these compounds are still inaccessible to date. Here we report a general strategy for the synthesis of a wide range of highly fluorinated biphenyls. In our studies we investigated crucial parameters, such as different phosphine ligands and the influence of various nucleophiles and electrophiles with different degrees of fluorination. These results extend the scope of the already very versatile Suzuki–Miyaura reaction toward the synthesis of very electron-poor products, making these more readily accessible. The presented methodology is scalable and versatile without the need for elaborate phosphine ligands or Pd-precatalysts

Toward Molecular Recognition: Three-Point Halogen Bonding in the Solid State and in Solution

A well-defined three-point interaction based solely on halogen bonding is presented. X-ray structural analyses of tridentate halogen bond donors (halogen-based Lewis acids) with a carefully chosen triamine illustrate the ideal geometric fit of the Lewis acidic axes of the former with the Lewis basic centers of the latter. Titration experiments reveal that the corresponding binding constant is about 3 orders of magnitude higher than that with a comparable monodentate amine. Other, less perfectly fitting multidentate amines also bind markedly weaker. Multipoint interactions like the one presented herein are the basis of molecular recognition, and we expect this principle to further establish halogen bonding as a reliable tool for solution-phase applications

Toward Molecular Recognition: Three-Point Halogen Bonding in the Solid State and in Solution

A well-defined three-point interaction based solely on halogen bonding is presented. X-ray structural analyses of tridentate halogen bond donors (halogen-based Lewis acids) with a carefully chosen triamine illustrate the ideal geometric fit of the Lewis acidic axes of the former with the Lewis basic centers of the latter. Titration experiments reveal that the corresponding binding constant is about 3 orders of magnitude higher than that with a comparable monodentate amine. Other, less perfectly fitting multidentate amines also bind markedly weaker. Multipoint interactions like the one presented herein are the basis of molecular recognition, and we expect this principle to further establish halogen bonding as a reliable tool for solution-phase applications