Diels–Alder Reactivity of Binuclear Complexes with Calixarene‐like Structures

Abstract

The regioselectivity of the Diels–Alder reaction between ω‐substituted dienoates and unsymmetrical dienophiles can be strictly controlled by “calixarene‐like” metal complexes of type A (see scheme). The reaction of the dienoate coligand in A with acrylonitrile leads to the exclusive formation of the regioisomer adduct I, which is in striking contrast to the low regioselectivity of the background reaction.

Selective anion encapsulation in solid-state Ln(iii)[15-metallacrown-5]3+ compartments through secondary sphere interactions

“…In the context of metallocavitands as a whole, the observation of satDC selectivity based on specific secondary sphere interactions supports the usefulness of functional groups that converge on guests with specific intermolecular interactions in a metallocavitand cavity. Benchmark reports of regioselective reactions on guests bound in the confines of Kersting's metallocavitand [40][41][42] highlight the promise of metallocavitands as a class of catalysts. However, the severe product inhibition in these systems also highlights areas ripe for future progress.…”

Addition Reactions: Cycloaddition

“…The reaction between the coordinated sorbinate co-ligand and acrylonitrile is controlled by the binding cavity of the complexes and is highly regioselective. 109 Treating serum albumins, BSA or HAS, with phthalocyanine-Cu(II) complexes produced Lewis acid catee alysts for highly enantioselective Diels-Alder reactions of azalactones with cyclopentadiene in aqueous medium. 110 The l-DOPA-derived monopeptide (Y = NR 2 )-Cu(II) complex (98) 1-acyl-3,5-dimethylpyrazoles with cyclopentadiene.…”

Enhanced Guest Affinity and Enantioselectivity through Variation of the Gd3+[15-Metallacrown-5] Side Chain

“…18−20 Fabbrizzi and others have used metallocavitands to prepare fluorescent sensors. 21,22 Reports of selective guest transformations in Kersting's dimetallic thiophenolate complexes 23,24 and catalytic reactions in other metallocavitands 25,26 further exemplify the promise of this class of supramolecular host.…”