Rhodium catalysts derived from a fluorinated phanephos ligand are highly active catalysts for direct asymmetric reductive amination of secondary amines
作者:Sophie H. Gilbert、Sergey Tin、José A. Fuentes、Tamara Fanjul、Matthew L. Clarke
DOI:10.1016/j.tet.2020.131863
日期:2021.1
An asymmetric hydrogenation of enamines is efficiently catalysed by rhodium complexed with a fluorinated version of the planar chiral paracyclophane-diphosphine ligand, Phanephos. This catalyst was shown to be very active, with examples operating at just 0.1 mol% of catalyst. This catalyst was then successfully adapted to Direct AsymmetricReductive Amination, leading to the formation of several tertiary
The secondary amine participating asymmetricreductiveamination remains an unsolved problem in organic synthesis. Here we show for the first time that secondary amines are capable of effectively serving as N-sources in direct asymmetricreductiveamination to afford corresponding tertiary chiral amines with the help of a selected additive set under mild conditions (0–25 °C). The applied chiral phosphoramidite
Asymmetric Hydrogenation of Unfunctionalized Enamines Catalyzed by Iridium Complexes of Chiral Spiro N,N-Diarylphosphoramidites
作者:Pucha Yan、Jianhua Xie、Qilin Zhou
DOI:10.1002/cjoc.201090293
日期:2010.9
Chiral spiro N,N‐diarylphosphoramidites were synthesized. These new chiral spiro monophosphoramidites were efficient ligands for iridium‐catalyzedasymmetrichydrogenation of unfunctionalized enamines derived from simple alkyl aryl ketones, providing chiral tertiary amines in good enantioselectivities (up to 90% ee).
Access to chiral tertiary amines via the iridium-catalyzed asymmetric hydrogenation of enamines
作者:Pradeep Cheruku、Tamara L. Church、Anna Trifonova、Thomas Wartmann、Pher G. Andersson
DOI:10.1016/j.tetlet.2008.10.035
日期:2008.12
The asymmetrichydrogenation of N,N-dialkyl and N-alkyl-N-aryl enamines to chiral tertiary amines was studied. All the N,P-ligated iridium complexes investigated were active catalysts for the reaction, but only those with bicycle-supported oxazoline-phosphine ligands gave reasonable stereoinduction. The best catalyst produced a range of chiral tertiary amines in up to 87% ee.
Enantioselective alkylation of aldehydes catalyzed by new chiral diselenides
作者:Thomas Wirth
DOI:10.1016/0040-4039(95)01668-8
日期:1995.10
Newchiraldiselenides were synthesized from readily available chiral amines. Their application in the catalytic addition of diethylzinc to aldehydes provided the secondary alcohols in up to 98 % ee.