Access to 2-Oxabicyclo[2.1.1]hexanes and their use in Scaffold Hopping.

Saturated isosteres of the -substituted benzene ring remain rare due to the paucity of methods to access complex bridged systems. Using blue-light-mediated [2 + 2] photocycloaddition chemistry, we have developed a quick and practical route to provide novel 2-oxabicyclo[2.1.

A Mild Synthesis of Aryl Triflates Enabling the Late-Stage Modification of Drug Analogs and Complex Peptides.

We report the discovery of a straightforward protocol to convert phenols into the corresponding aryl triflates using 1-methyl-3-((trifluoromethyl)sulfonyl)-1,3-dihydro-2H-benzo[d]imidazol-2-one in the presence of a fluoride source. This novel reagent can be handled without any precautions to exclude air or moisture making this method highly convenient. The reactions generally show very clean conversions within only a few minutes at room temperature.

Toward the Design of Molecular Chameleons: Flexible Shielding of an Amide Bond Enhances Macrocycle Cell Permeability.

A series of macrocycles inspired by natural products were synthesized to investigate how side-chains may shield amide bonds and influence cell permeability. NMR spectroscopy and X-ray crystallography revealed that the phenyl group of phenylalanine, but not the side-chains of homologous or aliphatic amino acids, shields the adjacent amide bond through an intramolecular NH-π interaction. This resulted in increased cell permeability, suggesting that NH-π interactions may be used in the design of molecular chameleons.