Nitrogenated aromatics from chitin

Abstract

Herein, we addressed the challenge of using two chitin-derived furans, namely 3-acetamido-5-ethylfuran (3A5EF) and 3-acetamido-5-(1-hydroxyethyl)furan (3A5HF), for the formation of 4-acetylaminophthalimides and other N-containing aromatic compounds. The transformation is carried...

Substituted anilides from chitin-based 3-acetamido-furfural

“…Inspired by Pastre et al , 30 we postulated that this retro Diels–Alder pathway could be suppressed by the addition of acetic anhydride. Acetic anhydride performs a dual role: (1) it traps intermediate 4 , stopping the backward reaction that would restore the ether bridge ( 3 ), and thereby it prevents the retro Diels–Alder reaction to proceed.…”

“…Returning to the original work of Pastre et al , 30 we wondered whether this new procedure would allow the same strategy for ketone 3A5AF . Avoiding the necessity to reduce the carbonyl- to the ethyl function prior to the Diels–Alder/aromatization cascade would considerably improve the applicability of the products.…”

“…While the formation of an anilide side product was already identified during development of the synthesis of 3A5AF , 19 it was only recently that the first targeted synthesis of anilides from a chitin-derived furan was published by Pastre et al (Scheme 1A). 30 A reduced analogue of 3A5AF , 3-acetamido-5-ethylfuran ( 3A5EF ), was used to prepare several substituted anilides via an acetic anhydride mediated Diels–Alder-aromatization sequence under acidic conditions. Based on a DFT study, the authors concluded that reduction of the conjugated carbonyl functionality was required to overcome reactivity limitations.…”

Expanding Heteroaromatic and 2-Aminosugar Chemical Space Accessible from the Biopolymer Chitin

“…independent synthesis of the natural product proximicin A [16], 3-azafurans [17,18] heteroaromatic scaffolds [19], 2-aminosugars [20] and in a diversity-oriented syn (DOS) programme that furnished a number of structurally distinct N-heterocycle We recently demonstrated that the inherent chirality present in chitin can be trans to the natural product epi-leptosphaerin A via the chiral pool di-HAF platform [22]. research groups have shown that 3A5AF (and derivatives) [23,24] and di-HAF [25 serve as dienes in the Diels-Alder reaction, while 3A5F has shown significant prom a platform chemical, including as a bioconjugation handle for N-cysteine's modifi [13].…”

“…We recently demonstrated that the inherent chirality present in chitin can be transferred to the natural product epi-leptosphaerin A via the chiral pool di-HAF platform [22]. Other research groups have shown that 3A5AF (and derivatives) [23,24] and di-HAF [25] can serve as dienes in the Diels-Alder reaction, while 3A5F has shown significant promise as a platform chemical, including as a bioconjugation handle for N-cysteine's modification [13].…”