Divergent access to 5,6,7-perifused cycles

Abstract

Nitrogen-containing heterocycles are the key components in many pharmaceuticals and functional materials. In this study, we report a transition metal-catalyzed high-order reaction sequence for synthesizing a structurally unique N-center 5,6,7-perifused cycle (NCPC). The key characteristics include the formation of a seven-membered ring by the 8π electrocyclization of various alkenes and aromatic heterocycles as π-components, in which metal carbene species are generated that further induce the cleavage of the α-C-H or -C-C bond. Specifically, the latter can react with various nucleophilic reagents containing -O, -S, -N, and -C. The stereo-controlled late-stage modification of some complicated pharmaceuticals indicates the versatility of this protocol.

Polar alcohol guest molecules regulate the stacking modes of 2-D MOF nanosheets

“…At the same time, in the middle of the TCA ligand is a N atom, which showed the lone pair electron effect, while the center of BTB was a benzene ring, so the polarity of the TCA ligand was stronger than that of BTB. 33–35 Thus, the N sites of TCA, exposed Zr 6 –OH/OH 2 and solvents are all polar, so the interactions are more complex, inducing the twisted nanosheets. In addition, the TCA ligands with triangular pyramidal structures easily generated wavy nanosheets, forming the twisted stacking nanosheets.…”