Continuous Flow Preparation of Enantiomerically Pure BINOL(s) by Acylative Kinetic Resolution
A polystyrene-immobilized isothiourea has been applied to the enantioselective acylative kinetic resolution (KR) of monoacylated BINOL(s) with inexpensive isobutyric anhydride in batch and flow. High selectivity values (s = 29 at 0 oC) and a remarkable stability of the catalytic system in the operat...
| Autores: | , , , |
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| Tipo de recurso: | artículo |
| Estado: | Versión aceptada para publicación |
| Fecha de publicación: | 2020 |
| País: | España |
| Institución: | Varias* (Consorci de Biblioteques Universitáries de Catalunya, Centre de Serveis Científics i Acadèmics de Catalunya) |
| Repositorio: | Recercat. Dipósit de la Recerca de Catalunya |
| OAI Identifier: | oai:recercat.cat:2072/450557 |
| Acceso en línea: | http://hdl.handle.net/2072/450557 https://doi.org/10.1002/adsc.201901420 |
| Access Level: | acceso abierto |
| Palabra clave: | 54 |
| Sumario: | A polystyrene-immobilized isothiourea has been applied to the enantioselective acylative kinetic resolution (KR) of monoacylated BINOL(s) with inexpensive isobutyric anhydride in batch and flow. High selectivity values (s = 29 at 0 oC) and a remarkable stability of the catalytic system in the operation conditions have been recorded for unsubstituted BINOL. No significant loss of activity/selectivity is recorded after 10 consecutive KR cycles in batch. A continuous flow process has been implemented and operated with a 100 mmol (32.8 g) sample of racemic monoacetylated BINOL in dichloromethane solution in an 84 hours experiment with a packed bed reactor containing 1g (f = 0.37 mmol.g-1) of the functional resin (s = 17-21). Residence time can be decreased to 10 min with the same reactor to achieve a conversion of 58% with a selectivity factor s = 17 when a more highly functionalized catalyst (f = 0.88 mmol.g-1) is used. This translates into a remarkable combined productivity of 5.5 mmolprod·mmolcat-1·h-1. |
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