The adsorption properties of framework Sn sites in a siliceous zeolite beta were examined by comparing the adsorption of acetonitrile, diethyl ether, and 2-methyl-2-propanol on a Sn-Beta zeolite, a purely siliceous Beta zeolite, and a siliceous Beta zeolite with impregnated SnO2, using temperature-programmed desorption (TPD) and thermogravimetric analysis (TGA). Adsorption stoichiometries close to one molecule per framework Sn site were observed for each of the probe molecules. Although the 1:1 complexes with acetonitrile and diethyl ether decompose reversibly upon mild heating in vacuo, the 1:1 complex formed by 2-methyl-2-propanol underwent dehydration to butene and water over a very narrow temperature range centered at 410 K. FTIR spectra of acetonitrile-d3 at a coverage of one molecule per site exhibit a υ(C–N) stretching frequency at 2312 cm–1 that is not observed with nonframework Sn, providing a convenient method for characterizing the presence of framework Sn sites. Water interacts strongly enough with the Sn sites to prevent adsorption of acetonitrile.

We report a one‐step process for the production of diesel fuel from biomass‐derived 5‐hydroxymethylfurfural (HMF). The reaction proceeds through the sequential transfer hydrogenation and etherification of HMF to 2,5‐bis(alkoxymethyl)furan, a potential biodiesel additive, catalyzed by a Lewis acid zeolite, such as Sn‐Beta or Zr‐Beta. An alcohol is used as a hydrogen donor and as a reactant in etherification. This cascade reaction can selectively produce high yields of the biodiesel additive (>80 % yield) from HMF with the Sn‐Beta catalyst and secondary alcohols, such as 2‐propanol and 2‐butanol.

A route to renewable phthalic anhydride (2-benzofuran-1,3-dione) from biomass-derived furan and maleic anhydride (furan-2,5-dione) is investigated. Furan and maleic anhydride were converted to phthalic anhydride in two reaction steps: Diels-Alder cycloaddition followed by dehydration. Excellent yields for the Diels-Alder reaction between furan and maleic-anhydride were obtained at room temperature and solvent-free conditions (SFC) yielding 96% exo-4,10-dioxa-tricyclo[5.2.1.0]dec-8-ene-3,5-dione (oxanorbornene dicarboxylic anhydride) after 4 h of reaction. It is shown that this reaction is resistant to thermal runaway because of its reversibility and exothermicity. The dehydration of the oxanorbornene was investigated using mixed-sulfonic carboxylic anhydrides in methanesulfonic acid (MSA). An 80% selectivity to phthalic anhydride (87% selectivity to phthalic anhydride and phthalic acid) was obtained after running the reaction for 2 h at 298 K to form a stable intermediate followed by 4 h at 353 K to drive the reaction to completion. The structure of the intermediate was determined. This result is much better than the 11% selectivity obtained in neat MSA using similar reaction conditions. Scheme 1 Route to renewable phthalic anhydride from biomassderived furan and maleic anhydride. † Electronic supplementary information (ESI) available. See