Boosting the guerbet reaction: A cooperative catalytic system for the efficient bio-ethanol refinery to second-generation biofuels

Valorization of Ethanol: Ruthenium-Catalyzed Guerbet and Sequential Functionalization Processes

“…For ethanol Guerbet reactivity, the Ru–acridine complex reported by Milstein in 2016 (Table ) provides high yields of higher-order alcohols at 73% (TON = 18 209) over 40 h, using 0.02 mol % catalyst loading . We note that a dual cooperative catalytic system employing a derivative of Shvo’s Ru catalyst/benzoquinone was recently reported by Mazzoni and co-workers to produce higher yields . The manganese pincer complex detailed by Liu in 2017 exhibits the current highest turnover numbers (TON > 114,120) and turnover frequencies (TOF > 3087 h –1 after 12 h) for a homogeneous catalyst, although with lower total alcohol yields (23% after 96 h with 0.1 mol % catalyst loading; Table ).…”

“…8 We note that a dual cooperative catalytic system employing a derivative of Shvo's Ru catalyst/benzoquinone was recently reported by Mazzoni and co-workers to produce higher yields. 28 The manganese pincer complex detailed by Liu in 2017 exhibits the current highest turnover numbers (TON > 114,120) and turnover frequencies (TOF > 3087 h −1 after 12 h) for a homogeneous catalyst, although with lower total alcohol yields (23% after 96 h with 0.1 mol % catalyst loading; Table 5). 10,29 In comparison, Ru-3 exhibits yields within 7% of Milstein's catalyst over much shorter reaction times (65% yield in 2 h), although with higher catalyst loading (0.2 mol %).…”

Progressive study on ruthenium catalysis for de(hydrogenative) alkylation and alkenylation using alcohols as a sustainable source

“…Although this protocol was developed using a phosphine-free catalyst in an aqueous medium and mild temperature was needed for good selectivity (which was much less than previous reports), its limitation is the use of a high catalyst and base loading. Cesari, Mazzoni and coworkers 36 employed a dual cooperative catalytic system to boost up the Guerbet reaction using a derivative of Shvo's Ru catalyst ( Ru-12 ) named (η 4 -3,4-bis-(4-methoxyphenyl)-2,5-diphenylcyclopenta-2,4-dienone) with imidazolium cation and benzoquinone (BQ) as a co-catalyst (Scheme 22). Specifically, 0.2 mol% of catalyst, 1.5 mol% of BQ, and 20 mol% of NaOEt were required to form 39% of n -butanol together with 63% of higher alcohols (C4–C10) within 4 h at 150 °C.…”

Advances in Catalytic Routes for the Homogeneous Green Conversion of the Bio‐Based Platform 5‐Hydroxymethylfurfural

“…Ru-hydride-containing Shvo catalyst 2 exploits the cyclopentadienone ligand as the basic site for the selective bifunctional hydrogenation of polar double bonds [90][91][92][93][94][95][96][97] and proved very useful also in HMF selective reduction of BHMF. [98] Noteworthy, the complex 2 is not the main actor of catalysis but behaves as catalyst precursor, leading to active species that participate in the HMF conversion mechanism.…”