Modular Monodentate Phosphoramidite Ligands for Rhodium-Catalyzed Enantioselective Hydrogenation
作者:Yan Liu、Kuiling Ding
DOI:10.1021/ja052749l
日期:2005.8.1
A new class of monodentate phosphoramidite ligands (DpenPhos) has been developed on the basis of the modular concept for Rh(I)-catalyzed asymmetric hydrogenations of a variety of olefin derivatives, affording the corresponding optically active compounds in excellent yields and enantioselectivities. The ligands have the advantages of facile preparation, tunable structure, and broad scope of substrates
Strategies for protection and deprotection of OH-groups in the presence of phosphines have been explored. Rate acceleration in the Baylis-Hillman reaction was observed when a hydroxyl phosphine was used as the catalyst. Rhodium complexes with chiral bisphospholanes are highly enantioselective catalysts for the asymmetrichydrogenation of various kinds of functionalized olefins such as dehydroamino
A Novel Chiral Ferrocenyl Phosphine Ligand from Sugar: Applications in Rh-Catalyzed Asymmetric Hydrogenation Reactions
作者:Duan Liu、Wenge Li、Xumu Zhang
DOI:10.1021/ol0269998
日期:2002.12.1
[structure: see text] A new chiral ferrocenyl diphosphine ligand 3 was synthesized from readily available D-mannitol. Rh-complex with this ligand showed high enantioselectivity and reactivity in the asymmetric hydrogenation of dehydroamino acid derivatives and itaconic acid derivatives. Up to over 99% ee and 10 000 TON were achieved with this catalytic system.
Asymmetric catalysis based on chiral phospholanes and hydroxyl phospholanes
申请人:The Penn State Research Foundation
公开号:US06337406B1
公开(公告)日:2002-01-08
Chiral phosphine ligands derived from chiral natural products including D-mannitol and tartaric acid. The ligands contain one or more 5-membered phospholane rings with multiple chiral centers, and provide high stereoselectivity in asymmetric reactions.
Conjugate addition of potassiumtrifluoro(organo)borates 2 to dehydroalanine derivatives 1, mediated by a chiral rhodium catalyst and in situ enantioselective protonation, afforded straightforward access to a variety of protected alpha-amino esters 3 with high yields and enantiomeric excesses up to 95%. Among the tested chiral ligands and proton sources, Binap, in combination with guaiacol (2-methoxyphenol)