Low-temperature catalytic hydrogenation of bio-based furfural and relevant aldehydes using cesium carbonate and hydrosiloxane

Abstract

A benign catalytic system consisting of Cs2CO3 and PMHS can effectively reduce furfural to furfuryl alcohol with a high yield of 99.5% at 25–80 °C via siloxane, which is also applicable to other aromatic aldehydes.

Hydrosilylation and hydroboration in a sustainable manner: from Earth-abundant catalysts to catalyst-free solutions

“…Furthermore, the Yang group applied carbonate-mediated hydrosilylation of carbonyls to the selective reduction of biobased derivatives like furfural and 5-hydroxymethylfurfural (HMF). 69,70 In the case of HMF, the hydrosilylation was achieved by using Ph 2 SiH 2 in the presence of potassium carbonate at rt. As a result, 2,5-bis(hydroxymethyl)furan was isolated in excellent yield (94%).…”

Heterogeneous Catalytic Upgrading of Biofuranic Aldehydes to Alcohols

“…Incorporating another third component, such as Sn (Rudiansono et al, 2014) or Co (Du, 2011) also increases the catalytic performances. Hydrogenation with hydrogen as a source of hydrogen has certain weaknesses, and high-pressure hydrogen often poses a safety hazard (He et al, 2018b; Long et al, 2019). Catalytic transfer hydrogenation (CTH) can be used as an alternative to reduce biomass-derived molecules, and a hydrogen donor (e.g., secondary alcohol) is used as a hydrogen source instead of molecular H 2 .…”

“…In addition, PMHS is soluble in most organic solvents due to its low viscosity (Kumar et al, 2017). Based on these findings, Long et al (2019) depicted a benign method to effectively catalyze the reduction of FF to FFA over commercially available Cs 2 CO 3 utilizing non-toxic and cheap PMHS as a hydrogen source, giving an excellent FFA yield of 99% (Table 4, entry 2).…”

“…Over the past several decades, different types of heterogeneous catalysts and advanced methods have been explored to catalyze the hydrogenation of bio-based furanic aldehydes to alcohols (Chen et al, 2014a). Several research groups are currently studying this reaction using various noble metals, such as Pd (Audemar et al, 2014; Li et al, 2018c), Pt (An et al, 2013; Shi et al, 2016), and Ru (Nishimura et al, 2014; Yuan et al, 2015b), non-noble metals, such as Cu (Lesiak et al, 2014; Upare et al, 2018) and ferrous metals (Fe, Ni, Co) (Yao et al, 2014; Yu et al, 2015; Halilu et al, 2016), solid acid-base catalysts, and alkali metal salt catalysts [e.g., K 2 CO 3 (Long et al, 2018), Cs 2 CO 3 (Long et al, 2019) and KF (Wu et al, 2018; Zhao et al, 2018)] for the catalytic upgrading of biomass-derived furanic aldehydes to alcohols.…”

Four-component defluorinative reaction of allylic fluorides, amidines, and Cs2CO3under transition-metal-free conditions

“…20 In addition, the perfluoroalkyl group also exerts an activating effect for tuning the reactivity of both the C–C double bond and allylic C–F bond. This work distinguished itself by several apparent advantages: (1) the ability to regiospecifically deliver “difficult-to-make” fluorinated products from “easy-to-prepare” starting materials in a highly efficient four-component manner; (2) the conversion of elusive C–F bond with four new C–N/C–O bond formation and a six-membered heterocycle construction; (3) the use of cesium carbonate (Cs 2 CO 3 ) as a cheap, green, and abundant CO equivalent which avoids the involvement of extremely dangerous, explosive, flammable, and toxic carbon monoxide gas or other sensitive reagents; 21 (4) a catalyst-free and additive-free reaction with broad substrate scopes, operational simplicity, and step economy which meets the requirements of green chemistry. 7…”