Hydrogenation in Ionic Liquids

Beneficial Contribution of Biosourced Ionic Liquids and Microwaves in the Michael Reaction

“…Biosourced ionic liquids were prepared using an acid-base reaction between the tetrabutylammonium or -phosphonium hydroxides (TBAOH and TBPOH, respectively) or cholinium hydroxide ChOH with natural chiral amino acids (S-proline, R-proline, and trans-4-hydroxy-Sproline) (Scheme 3). The synthetic methodology was inspired by Ohno's work [51] in 2005 and previously reported works for some phosphonium or ammonium derivatives [38][39][40][41][42][43][44][45]. Nine ionic liquids were prepared easily with high yields and purity (Table 1), and the choliniumbased ionic liquids were synthesized following similar procedures previously used with ammonium or phosphonium-based ionic liquids.…”

“…As previously mentioned, we prepared some biobased ionic liquids with natural carboxylates and used these in hydrogenation and Heck couplings [38][39][40][41][42][43][44][45]. Among these ILs, we prepared tetrabutylphosphonium and tetrabutylammonium prolinate or hydroxyprolinate.…”

Hydrogenation Reaction in Ionic Liquids

“…There are several book chapters, especially a comprehensive chapter written by Gathergood et al in 2011 [1] entirely dedicated to hydrogenation processes in ILs. Research on catalytic hydrogenations in ILs began in 1995 with the almost simultaneous work of Chauvin and Dupont.…”

Hydrogenation Catalysis in Biobased Ionic Liquids

“…Gathergood et al wrote, in 2011, a big chapter entirely dedicated to hydrogenation processes in ILs [48]. This chapter is quite complete.…”

“…Concerning the asymmetric hydrogenation leading to enantiomerically pure products [57], the source of chiral induction was generally due to the presence of chiral ligands (BINAP or BINAP derivatives) coordinated to a metal catalyst [58][59][60][61], Rh-and Ru-based catalysts being generally the favourite candidates [48].…”