TangPHOS ligand, asymmetric

An enantioselective version of this rhodium-catalyzed cyclization reaction with a TangPhos ligand was developed by the authors at a later date. It was hypothesized that the highly electron-rich ligand was so efficient at promoting asymmetric induction because of its ability to create a vacant coordinating site on the metal center through partial dissociation. ... 

A highly regio- and enantio-selective hydroformylation of alkenes, such as PhCH= CH2, CH2=CHCH2CN, and CH2=CHOAc, catalysed by ruthenium complexes with (g) 2,5-disubstituted phospholane ligands has been reported. With (83) as the ligand, the turnover rates over 4000 h-1 at 80 °C, have been attained.108 (Acac)Rh(CO)2-TangPhos [Tangphos = (84)] has been developed as a new enantioselective catalyst for asymmetric hydroformylation of norbornene and other [2.2.1]-bicyclic alkenes (55-92% ee).109... 

P-Amino acids have been shown to be an important class of compounds both in biomedical research and the pharmaceutical industry. These structural motifs are present in p-lactams and P-peptides and also serve as chiral templates for the synthesis of other pharmaceuticals. Perhaps the most convenient and straightforward method for the synthesis of P-amino acids is the catalytic asymmetric hydrogenation of p-(acylamino)acrylates 151. Some success has been reported for the Rh-catalyzed asymmetric hydrogenation of ( ) and (Z)- isomers of p-(acylamino)acrylates using chiral phosphorous ligands such as Me-DuPhos, DuanPhos, TangPhos, and other ligands. ... 

The asymmetric hydrogenation of cyclic enol acetate has also proven to be a challenging problem. In this respect, Me-PennPhos 125 was shown to be an effective ligand in the rhodium-catalyzed asymmetric hydrogenation of five- or six-membered cyclic enol acetates such as 172. " In addition, Tang et al. found that the TangPhos-Rh catalyst system provided good-to-excellent (92%-99%) enantioselectivities for a diverse set of aryl enol acetates. ... 

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