A wide overview of the biphasic production of 5-hydroxymethylfurfural and furfural from lignocellulosic sugars is presented together with a screening of solvents following a methodology based on COSMO-RS and section guides.

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A current challenge in catalysis is the development of methodologies for the production of bulk chemicals needed at levels of tens and hundreds of thousands of tons per year with the requirement to be produced at very low costs often being in the single-digit US dollar range. At the same time, such methodologies should address challenges raised by current manufacturing processes. Within this research area, a cyanide-free approach toward aliphatic nitriles used as industrial chemicals was developed starting from readily accessible n-alkenes as starting materials available in bulk quantities. This chemoenzymatic process concept is exemplified for the synthesis of nonanenitrile (as an n-/iso-mixture) and runs in water at low to moderate temperatures without the need for any types of cyanide sources. The process is based on a combination of a metal-catalyzed hydroformylation as the world-leading production technology for alkyl aldehydes with an emerging enzyme technology, namely, the recently developed transformation of aldoximes into nitriles through dehydration by means of aldoxime dehydratases. As a missing link, an efficient aldoxime formation with subsequent removal of remaining traces of hydroxylamine as an enzyme-deactivating component was found, which enabled the merging of these three steps, hydroformylation, aldoxime formation, and enzymatic dehydration, toward a nitrile synthesis without the need for purification of intermediates.

Over the past 20 years, thermomorphic multiphase systems (TMS) have been used as a versatile and elegant strategy for the recovery and recycling of homogeneous transition‐metal catalysts, in both batch‐scale experiments and continuously operated processes. TMS ensure a homogeneous reaction in a monophasic reaction mixture at reaction temperature and the recovery of the homogeneous transition‐metal catalyst through liquid–liquid separation at a lower separation temperature. This is achieved by using at least two solvents, which have a highly temperature‐sensitive miscibility gap. The suitability of commercially available solvents makes this approach highly interesting from an industrial point of view. For the first time, herein, all studies in the area of TMS are reviewed, with the aim of providing a concise and integral representation of this approach for homogeneous catalyst recovery. In addition to the discussion of examples from the literature, the thermodynamic fundamentals of the temperature‐dependent miscibility of solvents are also presented. This review also gives key indicators to compare different TMS approaches, for instance. In this way, new solvent combinations and in‐depth research, as well as improvements to existing approaches, can be addressed and promoted.

The application of thermomorphic solvent systems offers the combination of homogeneous catalysis in a single phase and catalyst recovery via phase separation. To increase economic feasibility the minimization of waste streams and side reactions is desired. For this, a continuous process for the hydroformylation of 1‐dodecene in the solvent system DMF/n‐decane is shown. While the Rh/Biphephos catalyst is recycled in DMF in a first loop, the n‐decane and remaining olefins are separated from the product via distillation to form the second loop. In this process the need for additional solvent supply and the isomerization reaction of 1‐dodecene is reduced significantly. The reaction toward internal olefins decreases from initially 15 to 3%. The stable hydroformylation process with a yield of the linear hydroformylation product of 55% and l/b‐ratio of 95/5 is shown for 120 h. © 2016 American Institute of Chemical Engineers AIChE J, 62: 4377–4383, 2016

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