No abstract

A convenient procedure was developed for the manufacturing of partially bio-ionic liquids (ILs) from renewable γvalerolactone (GVL) and cheap and readily available tetraalkylphosphonium bromides with excellent (>99%) yields. The novel ionic liquids were characterized by their temperature dependent vapor pressure, density, viscosity, and conductivity. We have proven that these ILs can be a useful medium for copper-catalyzed Ullmann-type coupling reactions without the use of any ligand or additive, representing an environmentally benign tool for the synthesis of various amines. Twenty cross-coupling products were isolated with good to excellent yields (50−87%).

The combined application of 31P NMR and pH measurements during the tri-isooctylamine-assisted aqueous/organic separation and purification steps after the sulfonation of diphenyl-alkyl-phosphines (Ph2PR; R = Me, n-Bu) and phenyl-dialkyl-phosphines (PhPR2; R = Me, n-Bu) resulted in the preparation of water-soluble alkyl-bis(m-sulfonated-phenyl)- (C6H4-m-SO3Na)2PR; R = Me, n-Bu) and dialkyl-(m-sulfonated-phenyl)- (C6H4-m-SO3Na)PR2; R = Me, n-Bu) phosphines in the presence of less than 0.5% phosphine oxides. When 2 equiv of the water-soluble phosphines were used per rhodium atom, no significant effect on the turnover frequency of the hydrogenation of maleic acid can be observed by using these phosphines.

It was demonstrated that the γ-valerolactone-based ionic liquid, tetrabutylphosphonium 4-ethoxyvalerate as a partially bio-based solvent can be utilized as alternative reaction medium for copper- and auxiliary base-free Pd-catalyzed Sonogashira coupling reactions of aryl iodides and functionalized acetylenes under mild conditions. Twenty-two cross-coupling products were isolated with good to excellent yields (72–99%) and purity (>98%). These results represent an example which proves that biomass-derived safer solvents can be utilized efficiently in common, industrially important transformations exhibiting higher chemical and environmental efficiency.

The hydroformylation of octene-1 and the removal of Co 2 (CO) 8 and HCo(CO) 4 from the reaction products including commercial C9 OXO-product were studied under biphasic conditions using an aqueous solution of different electrondonating sulfonated phosphine R n P(C 6 H 4 -m-SO 3 Na) 2 (n = 0, 1, 2; R = Me, Bu, Cp) ligands. Depending on the electronic and steric properties of the phosphines, 6−70 ppm residual cobalt concentrations could be achieved in the organic phase under 10 bar of CO/H 2 (1:1) at 75°C. The formation of several water-soluble-phosphine-substituted cobalt carbonyl species including Co 2 (CO) 6 (TPPTS) 2 , HCo(CO) 3 (TPPTS), HCo(CO) 2 (TPPTS) 2 , and [Co(CO) 3 (TPPTS) 2 ] + [Co(CO) 4 ] − were identified and monitored by in situ IR and NMR spectroscopy.