Practical Enantioselective Hydrogenation of α-Aryl- and α-Carboxyamidoethylenes by Rhodium(I)-{1,2-Bis[(<i>o</i>-<i>tert</i>-butoxyphenyl)(phenyl)phosphino]ethane}
作者:Barbara Mohar、Michel Stephan
DOI:10.1002/adsc.201200780
日期:——
The rhodium(I)-1,2-bis[(o-tert-butoxyphenyl)(phenyl)phosphino]ethane} [Rh(I)-(t-Bu-SMS-Phos)] catalyst system displayed prime efficiency in the hydrogenation of large series of α-amidostyrenes and α-amidoacrylates. Up to >99.9% enantiomeric excesses coupled with very high reaction rates were attained operating routinely under 1–10 bar of hydrogen at 22 °C in methanol. Examples include industrial substrates
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
Ligand-free palladium catalysed Heck reaction of methyl 2-acetamido acrylate and aryl bromides as key step in the synthesis of enantiopure substituted phenylalanines
作者:Charlotte E Willans、Jan M.C.A Mulders、Johannes G de Vries、André H.M de Vries
DOI:10.1016/j.jorganchem.2003.09.012
日期:2003.12
A range of substituted aryl bromides were coupled with methyl 2-acetamido acrylate using ligand-free palladium catalysis. Subsequently asymmetric hydrogenation with Rh/MonoPhos yielded substituted phenylalanines enantioselectivities (e.e. 92-99%). (C) 2003 Elsevier B.V. All rights reserved.
Synthesis and Application of Phosphinoferrocenylaminophosphine Ligands for Asymmetric Catalysis
作者:Neil W. Boaz、Elaine B. Mackenzie、Sheryl D. Debenham、Shannon E. Large、James A. Ponasik
DOI:10.1021/jo048312y
日期:2005.3.1
[GRAPHICS]A new class of bidentate ligands utilizing a phosphine-aminophosphine structure has been prepared on a ferrocenylethyl backbone in a straightforward and scalable fashion from acetylferrocene. The unique property of the alpha-ferrocenyl carbonium ion that allows the replacement of a variety of "leaving groups" with retention of configuration greatly facilitates the synthesis, and a number of ligands have been prepared by varying the nitrogen and phosphorus substituents on the aminophosphine. These readily prepared phosphinoferrocenylaminophosphines, known as BoPhoz ligands, show surprising hydrolytic and air stability, with no degradation after 3 years open to the air. The rhodium complexes of these ligands show exceedingly high enantioselectivities (generally >95% ee) and activities often in excess of 50 000 catalyst turnovers per hour for the asymmetric hydrogenation of a wide variety of dehydro-alpha-amino acid and itaconic acid derivatives. They also show high activity and good to excellent enantioselectivity for the hydrogenation of a number of alpha-ketoesters.
Silver-Promoted Direct Phosphorylation of Bulky C(sp<sup>2</sup>)–H Bond to Build Fully Substituted β-Phosphonodehydroamino Acids
作者:Hao-Qiang Cao、Hao-Nan Liu、Zhe-Yuan Liu、Baokun Qiao、Fa-Guang Zhang、Jun-An Ma
DOI:10.1021/acs.orglett.0c02229
日期:2020.8.21
A general and practical cross-dehydrogenative coupling protocol between readily available trisubstituted α,β-dehydro α-amino carboxylic esters and H-phosphites is described. This C(sp2)–H phosphorylation reaction proceeds with absolute Z-selectivity promoted by silver salt in a radical relay manner. The bulky tetrasubstituted β-phosphonodehydroamino acids were obtained in grams and added new modules