(Aryl)(2-furyl)alkanes and their derivatives, 20. Synthesis of symmetric bis- and tris(2-furyl)methanes

Abstract

New methods for the synthesis of symmetric 5,5'-disubstituted bis-and 5,5',5"-trisubstituted tris(2-furyl)methanes have been developed. Symmetric bis(2-furyl)methanes were prepared from 5-substituted 2-furylmethanols in the presence of concentrated perchloric acid. The attempted synthesis of (aryl)[bis(2-furyl)]methanes from (aryl)(2-furyl)methanols in the presence of acid catalysts failed. The reaction of 5-substituted 2-furaldehydes with ethylene glycol in the presence of strong acid catalysts led to tris(2-furyl)methanes. Plausible mechanisms of these transformations are discussed.

Synthetic Study of 5‐Hydroxymethylfurfural in Groebke‐Blackburn‐Bienaymé Reaction

“…Beyond this, the expected product 4 a was detected along with another product which was identified as the symmetric bis(2‐furyl)methane 6 a (Table 1, entry 2 and Figure 2). A possible explanation for the formation of bis‐(2‐furyl)methane derivative 6 a could be via self‐condensation of the hydroxymethyl functionality present in 4 a [45,46] . Similar decomposition results were obtained when the reaction was carried out without solvent in the presence of trifluoroacetic acid (TFA) as catalyst (Table 1, entry 3), recovering a high amount of insoluble products (humins formation) [10] .…”

5-Phenyl-2-furaldehyde: Synthesis, Reactions and Biological Activities

“…The conversion of 5-phenyl-2-furancarbaldehyde (3) into 2-hydroxy-1,2bis(5-phenylfuran-2-yl)ethanone (56) takes place in the presence of a base (Et 3 N) and thiazolium salt (74) . Also, 5-phenyl-2-furancarbaldehyde (3) was converted into tris(5-phenyl-2-furyl)methane (57) by the reaction with ethylene glycol (Scheme 50) (75) . (38) showed good antibacterial activity against Gram positive and Gram negative bacterial species (12) .…”

Efficient Synthesis of Bis(5‐arylfuran‐2‐yl)methane Scaffolds Utilizing Biomass‐Derived Starting Materials

“…Bis‐furyl methanes and their analogs [1] are an attractive class of compounds naturally present in licorice flavors [2] and coffee volatiles [3] . These structures have been used as precursors in the synthesis of condensed heterocyclic systems, [4] and as monomers and cross‐linking reagents in polymer manufacturing [5] . Previous reports on the synthesis of furyl methanes 3 (Scheme 1) can be classified into two general classes: The first utilizes a nucleophilic C2‐metallated furan ring 1 that undergoes a reaction with another furan ring bearing the bridge carbon (electrophile, 2 ), as shown in Scheme 1 ( left ) [6–8] .…”

“…[3] These structures have been used as precursors in the synthesis of condensed heterocyclic systems, [4] and as monomers and cross-linking reagents in polymer manufacturing. [5] Previous reports on the synthesis of furyl methanes 3 (Scheme 1) can be classified into two general classes: The first utilizes a nucleophilic C2-metallated furan ring 1 that undergoes a reaction with another furan ring bearing the bridge carbon (electrophile, 2), as shown in Scheme 1 (left). [6][7][8] The second class utilizes the inherent nucleophilic nature of the furan ring 4, which can attack soft electrophiles such as precomplexed furylalkynylcarbinol derivatives 5 [9,10] and Michael acceptors 6 [11] (Scheme 1, right).…”