372144-00-8Relevant articles and documents
Highly Efficient and Robust Enantioselective Liquid–Liquid Extraction of 1,2-Amino Alcohols utilizing VAPOL- and VANOL-based Phosphoric Acid Hosts
Pinxterhuis, Erik B.,Gualtierotti, Jean-Baptiste,Wezenberg, Sander J.,de Vries, Johannes G.,Feringa, Ben L.
, p. 178 - 184 (2017/12/15)
The large-scale production of enantiopure compounds in a cost-effective and environmentally friendly manner remains one of the major challenges of modern-day chemistry. The resolution of racemates through enantioselective liquid–liquid extraction was developed as a suitable solution but has remained largely underused, owing to a lack of highly efficient and robust chiral hosts to mediate the process. This paucity of hosts can in part be attributed to a poor understanding of the underlying principles behind these processes hindering the design of more efficient selectors. A previously untested class of hosts, VAPOL and VANOL derived phosphoric acids, has been studied in depth for the efficient enantioselective liquid–liquid extraction of 1,2-amino alcohols. A systematic investigation of extraction parameters was conducted, revealing many key interactions and DFT calculations illustrate the binding modes for the 1:1 complexes that are involved in chiral recognition. The resulting, now-optimized, procedures are highly robust and easy to implement. They are also easily scalable, as demonstrated by U-tube experiments.
Highly efficient enantioselective liquid-liquid extraction of 1,2-amino-alcohols using SPINOL based phosphoric acid hosts
Pinxterhuis, Erik B.,Gualtierotti, Jean-Baptiste,Heeres, Hero J.,De Vries, Johannes G.,Feringa, Ben L.
, p. 6409 - 6418 (2017/08/29)
Access to enantiopure compounds on large scale in an environmentally friendly and cost-efficient manner remains one of the greatest challenges in chemistry. Resolution of racemates using enantioselective liquid-liquid extraction has great potential to meet that challenge. However, a relatively feeble understanding of the chemical principles and physical properties behind this technique has hampered the development of hosts possessing sufficient resolving power for their application to large scale processes. Herein we present, employing the previously untested SPINOL based phosphoric acids host family, an in depths study of the parameters affecting the efficiency of the resolution of amino-alcohols in the optic of further understanding the core principles behind ELLE. We have systematically investigated the dependencies of the enantioselection by parameters such as the choice of solvent, the temperature, as well as the pH and bring to light many previously unsuspected and highly intriguing interactions. Furthermore, utilizing these new insights to our advantage, we developed novel, highly efficient, extraction and resolving protocols which provide remarkable levels of enantioselectivity. It was shown that the extraction is catalytic in host by demonstrating transport in a U-tube and finally it was demonstrated how the solvent dependency could be exploited in an unprecedented triphasic resolution system.
