New AB type monomers from lignocellulosic biomass

Abstract

A series of renewable novel bicyclic AB type polyester precursors have been prepared in good overall yield from lignocellulosic biomass. These advancements take full advantage of the differing oxidation states of functional groups in 5-(hydroxymethyl)furfural by chemoselective preparation of furanic hydroxy esters and applying benzyne-Diels–Alder cycloaddition/aromatization strategies.

Chemoenzymatic Synthesis of 5‐Hydroxymethylfurfural (HMF)‐Derived Plasticizers by Coupling HMF Reduction with Enzymatic Esterification

“…For comparison purposes we prepared 2,5‐bis(acetoxymethyl)furan in a one‐pot process by using a conventional acetylation method . For that, HMF was reduced in the presence of Co@C, using hydrogen and 2‐MHF as a solvent, at 110 °C and 10 bar during 10 h, achieving 93 % yield of BHMF.…”

Recent Advances on Diels‐Alder‐Driven Preparation of Bio‐Based Aromatics

“… [34] Yet, the latter aromatization step remains problematic, resulting in poor yields and highlighting the need for alternative approaches. In this sense, stepwise hydrogenation of 7‐ONB followed by acid‐promoted dehydroaromatization has emerged as a viable option [34,35] . Whereas Amberlyst 15 afforded the aromatic product in poor yields, HCl promoted the aromatization in 91 % yield.…”

“…In this sense, stepwise hydrogenation of 7‐ONB followed by acid‐promoted dehydroaromatization has emerged as a viable option. [ 34 , 35 ] Whereas Amberlyst 15 afforded the aromatic product in poor yields, HCl promoted the aromatization in 91 % yield. However, the diester is not compatible with the latter conditions, resulting in the diacid product.…”

“…The LUMO of aryne lies much lower comparing to unstrained alkynes, [36] contributing to a more favorable LUMO dienophile ‐HOMO diene with ED‐furans which correlates with the diversity of examples in the literature. [ 1c , 37 ] Interestingly, albeit only few examples of DA oxidized EW‐furans are reported,[ 34 , 35 ] benzyne reacts effectively with these species despite bearing only a slight increase of the HOMO comparing to unstrained alkynes. Such reactivity may be justified by distortion/interaction models, [38] given the strain release in the transition state.…”

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

“…Ethylene [a] 54 d: 2 % [84] 13 benzyne 55 e: 0 % [86] 14 acrylonitrile 55 j: 77 % [95] 56 j: 70 % [95] 15 maleic anhydride 56 k: R = NMe 2 ; 98 % [87] 56 l: R = OBn; 20 % [87] 16 methyl propiolate 56 m: R = OBn; 48 % [87] 17 ethylene 54 f: R = R 1 = H; 19 % [41] 54 g: R = Me, R 1 = H; 5 % [41] 18 benzyne 55 n: R = Me, R 1 = Ac; 72 %; [96] 56 n: R = Me, R 1 = Ac; 82 %; [96], [b] 19 ethylene 54 h: R = H; 0 % [41] 54 i: R = Me; 36 % [97] 54 j: R = Et; 59 % [98] 20 benzyne 55 o: R = H; 0 %; [86] 55 p: R = Me; 91 %; [99] 56 p: R = H; 89 %; [99], [c] [a] Formed in situ from ethanol. [b] Final yield after two-stage methodology including reduction of the double bond in 55 n followed by deoxygenation.…”