Diastereoselective synthesis of chiral non-racemic 2-substituted 2-boranatophosphino ethanoic acid: a potential intermediate to chiral ligands for asymmetric catalysis
摘要:
Chiral alpha-amidophosphine boranes 7a-b can be diastereoselectively alkylated, using a phenylglycinol derivative as a chiral inducer, to furnish alpha-substituted alpha-amidophosphine boranes 8-12 with up to 99% diastereoisomeric excess. Selective reduction of the amidophosphine boranes afforded optically pure beta-boranatophosphine-alcohol 13. The latter one can then be oxidized in boronatophosphine acid 14. (C) 2003 Elsevier Science Ltd. All rights reserved.