DOI: 10.3390/molecules28176210 ISSN:
Access to Enantiomerically Pure P-Chiral 1-Phosphanorbornane Silyl Ethers
Kyzgaldak Ramazanova, Soumyadeep Chakrabortty, Fabian Kallmeier, Nadja Kretzschmar, Sergey Tin, Peter Lönnecke, Johannes G. de Vries, Evamarie Hey-Hawkins- Chemistry (miscellaneous)
- Analytical Chemistry
- Organic Chemistry
- Physical and Theoretical Chemistry
- Molecular Medicine
- Drug Discovery
- Pharmaceutical Science
Sulfur-protected enantiopure P-chiral 1-phosphanorbornane silyl ethers 5a,b are obtained in high yields via the reaction of the hydroxy group of P-chiral 1-phosphanorbornane alcohol 4 with tert-butyldimethylsilyl chloride (TBDMSCl) and triphenylsilyl chloride (TPSCl). The corresponding optically pure silyl ethers 5a,b are purified via crystallization and fully structurally characterized. Desulfurization with excess Raney nickel gives access to bulky monodentate enantiopure phosphorus(III) 1-phosphanorbornane silyl ethers 6a,b which are subsequently applied as ligands in iridium-catalyzed asymmetric hydrogenation of a prochiral ketone and enamide. Better activity and selectivity were observed in the latter case.