From 5-Hydroxymethylfurfural (HMF) to Polymer Precursors: Catalyst Screening Studies on the Conversion of 1,2,6-hexanetriol to 1,6-hexanediol

Abstract

1,6-hexanediol (1) is an important polymer precursor for the polyester industry. In this paper, exploratory catalyst screening studies on the synthesis of 1 from 1,2,6-hexanetriol (2) are described via two different routes. The latter is available by a two-step procedure from 5-hydroxymethylfurfural (HMF, 3), a promising bio-based platform chemical. In the first approach, the direct catalytic hydrodeoxygenation of 2 to 1 with heterogeneous catalysts and molecular hydrogen was explored. Best results were obtained using a Rh-ReO x /SiO 2 catalyst in water (180°C, 80 bar H 2 , 20 h reaction time), leading to full conversion of 2 and 73 % selectivity to 1, the main byproduct being 1,5-hexanediol (4). In a second approach, 2 was first converted to tetrahydropyran-2-methanol (2-THPM, 5) in quantitative yield using triflic acid as catalyst (125°C, 30 min). Various catalysts were explored for the subsequent ring opening/hydrodeoxygenation of 5 to 1 using a hydrogenation protocol and the best results were obtained with a Rh-ReO x /SiO 2 catalyst, viz. 96 % selectivity to 1 at 26 % conversion (120°C, 80 bar H 2 , 20 h).

Catalytic Response and Stability of Nickel/Alumina for the Hydrogenation of 5‐Hydroxymethylfurfural in Water

“…The conversion of HMF into value-added chemicals has received increasing interest over the last decade [2,3,8,9] during which aw ide variety of heterogeneousm etal (i.e.,N i, Cu, Pd, Pt, Ru)-supported catalysts weres tudied. [10,11] Although most research focused on CÀOh ydrogenolysis (e.g.,d imethyl furan) and ring-opening products (e.g.,h exanetriol, C 5 and C 6 polyols), there are fewer reports on the selectiveh ydrogenation of HMF towards tetrahydrofuran-2,5-diyldimethanol (THFDM; Scheme1).…”

Kinetics of Catalytic Hydrogenation of 5-Hydroxymethylfurfural to 2,5-bis-Hydroxymethylfuran in Aqueous Solution over Ru/C

“…For example, hydrogenation of 5‐HMF produces 2,5‐bis‐hydroxymethylfuran (BHMF), 2,5‐bis‐hydroxymethyltetrahydrofuran (BHMTHF), 5‐methylfurfuryl alcohol (MFA), and 2,5‐dimethylfuran (DMF). It can be used in pharmaceutical intermediates, fine chemicals, dyes, food, resins, polymers, fuel additives, and fibers industries .…”

Selective Hydrogenation of Biomass-Based 5-Hydroxymethylfurfural over Catalyst of Palladium Immobilized on Amine-Functionalized Metal–Organic Frameworks

“…17 In addition, DHMTHF is an important precursor to the production of 1,6-hexanediol which is a valuable chemical in the manufacture of polymer plastics. 11, [19][20][21][22][23][24] In the literature search for the selective hydrogenation of HMF to DHMTHF, Schiavo et al…”