Clickable Bambusurils to Access Multivalent Architectures

Abstract

Propargylated bambus[4,6]urils were prepared by an efficient one-step condensation of dipropargylglycoluril with formaldehyde under microwave irradiation. Their functionalization by click chemistry (CuAAC) afforded new multivalent architectures decorated with 8 or 12 ligands. Grafting of glycosides provided water-soluble glycobambus [4,6]uril platforms with glucosyl 12 BU[6] showing good affinity toward iodide anion in aqueous medium.

Bambus[4,6]urils as Dual Scaffolds for Multivalent Iminosugar Presentation and Ion Transport: Access to Unprecedented Glycosidase-Directed Anion Caging Agents

“…These building blocks were consequently selected for the synthesis of the first examples of bambus[ n ]urils-based iminosugars 3 – 11 ( Figure 1 ). Based on our recent results [ 14 ], octapropargylated BU[4] 1 and dodecapropargylated BU[6] 2 were used as clickable platforms to generate architectures decorated with 8 and 12 DNJ inhitopes, respectively. For this purpose, azide-armed N -hexyl DNJ 12 , N -nonyl DNJ 13 and N -nonyl-trivalent DNJ-dendron (tripod) 14 were chosen as peripheral ligands to generate corresponding neoglyco 8 BU[4] 3–5 and neogluco 12 BU[6] 6 – 11 derivatives.…”

“…First, the dipropargylated BU[4] platform 1 was prepared in one step and with 60% yield by condensation of propargylglycoluril and formaldehyde following our reported procedure [ 14 ]. Propargyl 8 BU[4] 1 was then reacted with peracetylated azido-functionalized C6-DNJ 12 [ 37 , 39 ] through a copper(I)-catalyzed azide alkyne cycloaddition reaction (CuAAC) in the presence of sodium ascorbate in DMSO/ t BuOH/H 2 O to acquire protected (DNJ-OAc-C6) 8 BU[4] 15 with 54% yield.…”

“…First, following our reported procedure, condensation of dipropargyl glycoluril with formaldehyde and TBABr as template promoted the formation of Br − @propargyl 12 BU[6]BU.TBA + 2 with 55% yield [ 14 ]. A subsequent CuAAC reaction of 2 with azide-armed DNJ 12 (C6 linker) afforded fully functionalized Br - @(DNJ-C6-OAc) 12 BU[6].Na + 18 with 70% yield.…”

“…We have previously synthesized allylated bambus[4,6]urils that were submitted to thiol–ene click coupling (TEC) with thiosugars to generate the corresponding 8-12 thiosugar-functionalized bambus[4,6]urils [ 12 , 13 ]. As a proof of concept, we recently developed an alternative strategy using propargylated bambus[4,6]urils able to be post-functionalized by click chemistry (CuAAC) so as to afford multivalent architectures bearing 8 or 12 glucose units [ 14 ].…”

X-ray structure of an unusual glycoluril derivative conformation: Structural analysis and influencing factors

“…As an interesting research objective, glycoluril units are widely used to design interesting supramolecular structures due to their concave skeletons. 9–12 These versatile molecules are designed as host molecules with cavities such as molecular capsules, 13,14 the cucurbit[n]uril family of macrocycles 15–17 and analogues, 18 or with semi-cavities such as molecular clips. 19,20 Among them, clip-shaped glycoluril derivatives have attracted much interest due to their ability to function as excellent receptors.…”