Bottom-up modular synthesis of well-defined oligo(arylfuran)s

Abstract

Oligofurans have attracted great attention in the field of materials over the last decades because of their several advantages, such as strong fluorescence, charge delocalization, and increased solubility. Although unsubstituted or alkyl-substituted oligofurans have been well-established, there is an increasing demand for the development of the aryl decorated oligofuran with structural diversity and unrevealed properties. Here, we report the bottom-up modular construction of chemically and structurally well-defined oligo(arylfuran)s by de novo synthesis of α,β′-bifuran monomers and late-stage bromination, stannylation and subsequent coupling reaction. The preliminary study of the photophysical properties demonstrated that the polarity-sensitive fluorescence emission and high quantum yields in THF solution could be achieved by modulating the aryl groups on the oligo(arylfuran)s. These twisted molecules constitute a new class of oligofuran backbone useful for structure−activities relationship studies. Meanwhile, the experimental studies and calculations showed that tetrafurans have appropriate HOMO energy levels, and could therefore potentially be high-performance p-type semiconductors.

Modular construction of α-furanyl ketones via semi-pinacol rearrangement-mediated ring expansion

“…10 As a continuation of our interest in alkyne chemistry 11 and also inspired by metal carbene-involved semi-pinacol rearrangement, 12 we have developed the construction of chemically and structurally well-defined oligo(arylfurans) via a de novo synthesis of bifuran monomers by 1,2-alkyne migration and a subsequent palladium-catalyzed cross-coupling reaction (Scheme 1d). 13 On the other hand, transition-metal-catalyzed cyclization reactions of conjugated enynals or enynones through a 5- exo-dig nucleophilic attack have become an efficient way to generate the α-furanyl carbene intermediate. 14 Considering the significance of functionalized medium- and large-ring ketones, 15 we have initiated a program directed at developing α-furanyl carbene-mediated ring expansion reactions by means of semi-pinacol rearrangement.…”

Copper-Catalyzed 6-endo-dig Cyclization–Coupling of 2-Bromoaryl Ketones and Terminal Alkynes toward Naphthyl Aryl Ethers in Water

“…Due to easy substrate accessibility and step economy, the cyclization reaction of alkynes has unarguably become an important and efficient strategy for the synthesis of various heterocyclic and carbocyclic compounds . However, to the best of our knowledge, the synthesis of naphthyl aryl ethers through direct cyclization–coupling reaction of alkynes has not yet been achieved.…”

Synthesis of Indeno[1,2-c]furans via Cobalt-Catalyzed Radical–Polar Crossover [3 + 2] Cycloaddition of o-Alkynylaryl β-Dicarbonyls

“…Fused polycyclic furans are interesting structural motifs widely spread in natural products. − In addition, the unique charge-transporting ability of fused polycyclic furans in the solid state also renders them to be promising organic semiconductors. , In this context, tremendous success has been achieved regarding their efficient and sustainable preparation, which serves as the background for further investigations of their rich properties in biological and materials chemistry. − …”

“…1−4 In addition, the unique charge-transporting ability of fused polycyclic furans in the solid state also renders them to be promising organic semiconductors. 5,6 In this context, tremendous success has been achieved regarding their efficient and sustainable preparation, which serves as the background for further investigations of their rich properties in biological and materials chemistry. 7−11 Among various fused polycyclic furans, indeno [1,2-c]furan is an interesting polycyclic scaffold, featuring a fused furan and indenone framework.…”

“…The substrate scope of this cobalt-catalyzed intramolecular [3 + 2] cycloaddition was then investigated (Scheme 2). Concerning the o-alkynyl moiety, a variety of para-(3−5), meta- (6), and ortho-substituted (7) phenylacetylenes were all well tolerated. The naphthalene moiety was also conveniently installed in the indeno[1,2-c]furan (8).…”