This work introduces the use of 8-aminoquinoline subcomponents to generate complex three-dimensional structures. Together with a tris(formylpyridine), 8-aminoquinoline condensed around Zn II templates to produce a tris(tridentate) ligand. This ligand is incorporated into either a tricapped trigonal prismatic Zn II 9 L 6 structure or a pair of pseudo-octahedral Zn II 6 L 4 diastereomers, with S 4 and D 2 symmetries. Introduction of a methyl group onto the aminoquinoline modulated the coordination sphere of Zn II , which favored the Zn II 9 L 6 structure and disfavored the Zn II 6 L 4 assembly. The tricapped trigonal prismatic Zn II 9 L 6 architecture converted into a single Zn II 6 L 4 cage diastereomer following the addition of a dianionic 4,4′dinitrostilbene-2,2′-disulfonate guest. Four of these guests clustered tightly at the four windows of the Zn II 6 L 4 cage, held in place through electrostatic interactions and hydrogen bonding, stabilize a single diastereomeric configuration with S 4 symmetry.
A selectivity switch in a RhII/carbene‐triggered cyclopentannulation with catalytic InCl3 is reported for the first time, affording both diastereomers of the fused spiroindolines and an unusual bridged tetracyclic indoline in high yields with excellent selectivities. Mechanistic studies indicate an intramolecular annulation of the indole with an in situ formed aminocyclopropane. The stepwise thermal conversions from the kinetic spiroindoline to the metastable bridged indoline, and then to the thermodynamic spiroindoline, involving a ring‐opening rearrangement of a cyclopentane, is crucial for selectivity control.
A selectivity switch in a RhII/carbene‐triggered cyclopentannulation with catalytic InCl3 is reported for the first time, affording both diastereomers of the fused spiroindolines and an unusual bridged tetracyclic indoline in high yields with excellent selectivities. Mechanistic studies indicate an intramolecular annulation of the indole with an in situ formed aminocyclopropane. The stepwise thermal conversions from the kinetic spiroindoline to the metastable bridged indoline, and then to the thermodynamic spiroindoline, involving a ring‐opening rearrangement of a cyclopentane, is crucial for selectivity control.
The first enantioselective copper catalyzed cyclopropanation of internal olefins with diazomalonates is reported. This process provides a new method for the synthesis of chiral 1,1-cyclopropane diesters. With a chiral bi-side arm bisoxazoline-copper(I) complex, the reaction performed well over a series of substrates, giving the desired products in good yields (up to 95%) and excellent enantioselectivities (90-95% ee).
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.