Synthesis of 2-Azidomethyl-5-ethynylfuran: A New Bio-Derived Self-Clickable Building Block

Abstract

2-Azidomethyl-5-ethynylfuran, a new ambivalent compound with both azide and alkyne moieties that can be used as a self-clickable monomer, is synthesized starting directly from renewable biomass. The reactivity of the azide group linked to furfural is tested via the efficient preparation of a broad range of furfural-containing triazoles in good to excellent yields using a 'green' copper(I)-catalyzed azide-alkyne cycloaddition procedure. Access to new bio-based chemicals and oligomeric materials via a click-chemistry approach is also demonstrated using this bio-derived building block.

Unusual Effect of Impurities on the Spectral Characterization of 1,2,3-Triazoles Synthesized by the Cu-Catalyzed Azide–Alkyne Click Reaction

“…5-(Azidomethyl)­furfural and compounds 1a , 1m , and 1n were synthesized according to the published method, and the physical and spectral characteristics of the obtained substances were in agreement with those described …”

The Increasing Value of Biomass: Moving From C6 Carbohydrates to Multifunctionalized Building Blocks via 5‐(hydroxymethyl)furfural

“…Classical methods of reductive amination with borohydrides as reducing agents afford furanic amines 18 via formation of imine intermediates [48] . The same outcome can be achieved with more environmentally friendly transition metal‐catalyzed [27,45a,e,49] or biocatalyzed [50] methodologies.…”

“…Product 6 makes a strong candidate platform for "click" chemistry due to the capability of entering the Cu-catalyzed [3 + 2] cycloaddition at both azide and alkyne fragments. [27] Although chemical reactivity of CMF makes this building block attractive for several applications, a care should be taken considering possible formation of Cl-containing wastes. At both stages, CMF synthesis and further functionalization/usage, careful planning is required to avoid contamination of the environment with Cl-containing by-products and wastes.…”

“…Product 6 , which contains a combination of triple bond and azide fragment, can be obtained by reacting 5 with the Ohira‐Bestmann reagent. Product 6 makes a strong candidate platform for “click” chemistry due to the capability of entering the Cu‐catalyzed [3+2] cycloaddition at both azide and alkyne fragments [27] …”

Atom‐economic Approach to the Synthesis of α‐(Hetero)aryl‐substituted Furan Derivatives from Biomass

“…Since [2 + 2 + 2]-cycloaddition requires the presence of a triple bond in a substrate, 2hydroxymethyl-5-ethynylfuran (HMEF) was synthesized according to known methods. [46][47][48] It is important to note that HMEF can be prepared directly from HMF in one step with excellent yield. [46] There are many transition-metal-based catalysts that can perform [2 + 2 + 2]-cycloaddition.…”