The monodentate phosphoramidite MonoPhos has been used in the rhodium-catalysed asymmetrichydrogenation of N-acetyl-α-arylenamides. This ligand is readilyavailable via a one-step procedure and is air stable. Its Rh(I) complex, which is an effective catalyst precursor for the hydrogenation of dehydroamino acids, also gives high enantioselectivities for this class of substrates. Because of the facile
A new family of ferrocenylphosphane ligands has been prepared. Their flexible synthesis allows many structural modifications. The asymmetric induction of these ligands was examined in the hydrogenation of functionalized C=C, C=O, and C=N bonds. The enantioselectivity of the reaction was strongly dependent on the substituent R at the position alpha to the ferrocene moiety. In many cases, both enantiomeric
Monodentate Phosphoramidites: A Breakthrough in Rhodium-Catalysed Asymmetric Hydrogenation of Olefins
作者:Michel van den Berg、Adriaan J. Minnaard、Robert M. Haak、Michel Leeman、Ebe P. Schudde、Auke Meetsma、Ben L. Feringa、André H. M. de Vries、C. Elizabeth P. Maljaars、Charlotte E. Willans、David Hyett、Jeroen A. F. Boogers、Hubertus J. W. Henderickx、Johannes G. de Vries
DOI:10.1002/adsc.200390026
日期:2003.1
ligands for the rhodium-catalysed asymmetrichydrogenation of olefins. Very high enantioselectivities were obtained with MonoPhos (7a) the simplest member of this class, a ligand that is prepared in a single step from BINOL and HMPT. Turnover numbers up to 6000 have been obtained in the hydrogenation of dehydroamino acid derivatives. Enantioselectivities in the hydrogenation of dehydroamino acids are solvent
Catechol-Based Phosphoramidites: A New Class of Chiral Ligands for Rhodium-Catalyzed Asymmetric Hydrogenations
作者:Rob Hoen、Michel van den Berg、Heiko Bernsmann、Adriaan J. Minnaard、Johannes G. de Vries、Ben L. Feringa
DOI:10.1021/ol049726g
日期:2004.4.1
[reaction: see text] The synthesis and application of a new class of catechol-based phosphoramidites is described. Ees up to 99% were obtained in the rhodium-catalyzedasymmetrichydrogenation of dehydroamino acids and enamides.
A new family of readily available, recoverable and soluble polymer-monophosphite ligands were prepared and successfully used in the Rh-catalyzed asymmetric hydrogenation of enamides and β-dehydroamino acid esters, in which up to 99 and 99.9% ee were obtained, respectively.