Attachment of a Ru^II Complex to a Self-Folding Hexaamide Deep Cavitand

Abstract

We report the design, synthesis and characterization of a new Ru metallocavitand that is catalytically active in alkene epoxidation reactions. The elaboration of the resorcin[4]arene's aromatic cavity produced a self-folding, deep hexaamide cavitand featuring a single diverging terpyridine (tpy) group installed at its upper rim. The construction of the metallocavitand involved the initial chelation of a Ru chloride complex by the tpy ligand followed by the incorporation of 2-(phenylazo)pyridine (azpy) as an ancillary ligand. The resulting Ru chloro complex was converted into the catalytically active aqua counterpart by a ligand exchange process.

A Deep Cavitand Receptor Functionalized with Fe(II) and Mn(II) Aminopyridine Complexes for Bioinspired Oxidation Catalysis

“…The selectivities obtained in the oxidation reactions so far tested with substrates that form kinetically stable complexes with the receptor do not significantly differ from those obtained with a model compound, suggesting that the oxidation steps are occurring to a significant extent outside the cavity. To the best of our knowledge, this system represents the first example of a sizeable container functionalized with a coordination complex capable of a) maintaining catalytic activity in selective C-H/C=C oxidation reactions, 7 1D and 2D NMR, HRMS, UV-Vis spectra. X-ray diffraction data for 6 and 2•Fe 2 Cl 4 O.…”

Shape Selectivity of a Metallo Cavitand Host Allows Separation of n‐Alkanes from Isooctane

“…In the absence of guest, cavitand 1 takes unreceptive kite conformation, on treatment with Pd(II), the exposed N atoms coordinated with the metal and formed a 2 : 1 metal:cavitand complex, Cav‐Pd in vase conformation. The placement of metals in the walls of a cavitand [ 28 ] typically slows exchange of the guests [ 29 ] and stabilizes the receptive vase conformation. [ 30‐31 ] The chelation of Pd(II) in Cav‐Pd results in a restricted size and fixed space of the metallo cavitand that imparted selectivity for particular guests in a mixture.…”

Recent Advances in the Applications of Water‐soluble Resorcinarene‐based Deep Cavitands

“…Recently, we reported a water‐soluble cavitand H6 [25] and its palladium(II) derivative H6 − 2Pd (Figure 5 ). [26] The coordination rigidifies the cavity and stabilizes the receptive vase shape,[ 27 , 28 ] which imparts a welcome selectivity in guest binding. We applied the restricted volume of metallo‐cavitand H6 − 2Pd and its dynamics to separate p ‐functionalized toluenes from their isomers in liquid–liquid extraction processes (Figure 5 ).…”