Alternative intermediates for glycerol valorization: iridium-catalyzed formation of acetals and ketals

Abstract

The organoiridium derivatives [Cp*IrCl2]2 (Cp* = pentamethylcyclopentadienyl) and [Cp*Ir(Bu2-NHC)Cl2] (Bu2-NHC = 1,3-di-n-butylimidazolylidene) catalyze glycerol acetalization with several ketones and aldehydes, as well as transacetalization

Catalytic conversion of glycerol for sustainable production of solketal as a fuel additive: A review

“…In fact, iridum catalyzed ketalization reactions are promising and have been well studied among other transition metal catalysts [60][61][62][63][64]. The most active catalyst for the ketalization reaction was [CpIrCl 2 ] 2 (Cp¼ pentamethylcyclopentadienyl) [59], with a glycerol conversion of 87% and 98% selectivity towards solketal in a batch reactor (other experimental conditions were: 40°C, [Ir]¼3.0 Â 10 À 3 M, [glycerol]/[Ir]¼ 500, and 1 h reaction time). Li's group specifically studied the performance of mesoporous substituted silicates [65], in which the metal atoms were incorporated in the silicate framework.…”

“…Transition metal catalysts have demonstrated good catalytic performance in glycerol ketalization [59]. In fact, iridum catalyzed ketalization reactions are promising and have been well studied among other transition metal catalysts [60][61][62][63][64].…”

Recent Advances in Catalytic Conversion of Glycerol

“…Crotti et al investigated the organoiridium derivatives [Cp * IrCl 2 ] 2 (Cp * = pentamethylcyclopentadienyl) and [Cp * Ir(Bu 2 -NHC)Cl 2 ], (Bu 2 -NHC = 1,3-di-nbutylimidazolylidene) as the catalysts for the acetalization and transacetalization of glycerol with ketones and aldehydes. [1,3]dioxan-5-ols were major products in all those catalytic reactions (380).…”

Room temperature acetalization of glycerol to cyclic acetals over anchored silicotungstates under solvent free conditions

“…12 Traditionally, the acetalization of glycerol was carried out by using mineral acids as homogeneous catalysts. These hitches can be overcome by using heterogeneous catalysts such as alumina, 13 aluminosilicates, 14 resins, 15 transition metal complexes, [16][17][18] and mixed metal oxides. These hitches can be overcome by using heterogeneous catalysts such as alumina, 13 aluminosilicates, 14 resins, 15 transition metal complexes, [16][17][18] and mixed metal oxides.…”