Porous, Naturally Derived Hafnium Phytate for the Highly Chemoselective Transfer Hydrogenation of Aldehydes with Other Reducible Moieties

Abstract

Both the utilization of naturally occurring compounds to prepare functional materials and the selective conversion of aldehydes with other reducible moieties (ORMs) are very attractive topics. Herein, we synthesized a novel porous material, hafnium phytate (Hf‐Phy), by using naturally derived sodium phytate as the building block. Hf‐Phy has plenty of mesopores centered around 11.8 nm. Hf‐Phy showed excellent performance for the transfer hydrogenation of aldehydes with ORMs by using 2‐propanol as the hydrogen source with high selectivities (95–100 %) for alcohols without reducing ORMs. Systematic studies suggested that the oxophilicity of Hf4+ and the basicity and structure of Hf‐Phy contributed significantly to the excellent performance. Additionally, Hf‐Phy could be used over at least five cycles without any decrease in activity or selectivity.

Strong Oxophilicity of Zr Species in Zr4+-Exchanged Montmorillonite Boosted Meerwein–Ponndorf–Verley Reduction of Renewable Carbonyl Compounds

“…Besides, owing to the lack of suitable acid–base pairs (Sn 4+ –O 2– ) in Sn-MMT, the yield of GVL was very low with Sn-MMT as the catalyst. These results indicated the intrinsic activity of Zr 4+ and Hf 4+ on MPV reduction, which was consistent with some reported results. − In the control experiments using the corresponding metal salts as the catalysts (Table S2), GVL was detected only when using ZrCl 4 and HfCl 4 as the catalysts, further confirming the key role of Zr 4+ (or Hf 4+ ) on MPV reaction. Considering the higher cost of Hf than Zr, Zr-MMT rather than Hf-MMT was selected as the optimal catalyst to investigate the influence of various reaction parameters.…”

“…Meerwein–Ponndorf–Verley (MPV) reduction, which employs suitable alcohols as the hydrogen resources, is a feasible strategy to achieve chemoselective hydrogenation of carbonyl groups. Generally, MPV reduction of carbonyl groups can be promoted by Al-, − Sn-, , Hf-, − or Zr-based catalysts, − which have lower hydrogenation activity on other reducible groups, thus making MPV reduction highly selective on carbonyl groups. Among various catalysts, Zr-based catalysts (i.e., inorganic materials and organic–inorganic hybrids) are the most used class for MPV reduction of carbonyl groups.…”

Toward a Better Understanding of Intrinsic Activity Trends in Zr-Based Heterogeneous Catalysts for Meerwein–Pondorf–Verley Reduction of Levulinate Esters

“…Dumesic and co-workers were the first to report the successful implementation of MPV chemistry for both batch and continuous production of GVL from levulinates, where ZrO 2 was identified as the best catalyst among numerous metal oxide catalysts . This pioneering work has stimulated a decade of intensive research on the design and synthesis of “novel” heterogeneous catalysts for the MPV reduction of LA and its esters under mild conditions, among which numerous Zr­(Hf)-based materials have emerged as efficient catalysts for this important class of biomass transformations. − The Zr­(Hf)-based heterogeneous catalysts hitherto reported for the MPV reductions of bioderived carbonyl compounds can be broadly classified into purely inorganic (hydroxides, oxides, and zeolites ,,− ) and crystalline/noncrystalline inorganic–organic hybrid catalysts (e.g., metal–organic-frameworks (MOFs) and Zr-phytates, among others ,,,,− ). Despite the wide spectrum of MPV catalysts developed over the past decade, a systematic comparison and in-depth understanding of their catalytic performances is generally lacking, stymying more focused efforts to analyze, design, and optimize truly promising systems for the target reactions.…”

Deep eutectic solvent-assisted fabrication of zirconium phytate thin nanosheets for important biomass transformations

“…Despite many advances ( Shao et al., 2021 ; Song et al., 2015 , 2018 ; Wang et al., 2018 ; Wu et al., 2018 ; Xue et al., 2016b ), the applications of M-Phy in catalysis are still significantly limited by the common drawbacks in heterogeneous catalysis. One of the main challenges is that the heterogeneity can increase the difficulty of the interaction between catalytically active sites and reactants.…”