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A Continuously Regenerable Chiral Ammonia Borane for Asymmetric Transfer Hydrogenations
Author(s) -
Zhou Qiwen,
Meng Wei,
Yang Jing,
Du Haifeng
Publication year - 2018
Publication title -
angewandte chemie international edition
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 5.831
H-Index - 550
eISSN - 1521-3773
pISSN - 1433-7851
DOI - 10.1002/anie.201806877
Subject(s) - ammonia borane , dehydrogenation , borane , chemistry , phosphoric acid , transfer hydrogenation , ammonia , organic chemistry , catalysis , ruthenium
Abstract A novel chiral ammonia borane was designed and developed through the dehydrogenation of ammonia borane with a chiral phosphoric acid, which was highly effective for the asymmetric transfer hydrogenation of imines and β‐enamino esters to afford high levels of reactivities and enantioselectivities. Significantly, this chiral ammonia borane can be continuously regenerated during the transfer hydrogenation with the assistance of water and ammonia borane, which made it possible to obtain satisfactory results using only 0.1 mol % of the chiral phosphoric acid. Notably, the role of chiral phosphoric acid is to produce the chiral ammonia borane.