Heavyweight “R-SMS-Phos” Ligands in the Olefins’ Hydrogenation Arena
作者:Borut Zupančič、Barbara Mohar、Michel Stephan
DOI:10.1021/ol100184p
日期:2010.3.19
A series of enantiopure P-stereogenic 1,2-bis[(o-RO-phenyl)(phenyl)phosphino]ethane (R-SMS-Phos) ligands wherein R= i-Pr, i-Bu, t-Bu, 3-Pen, and CH2TMS was assessed in the Rh(I)-catalyzed hydrogenation of an indicative set of olefins. The best performing t-Bu-SMS-Phos ligand was screened against a wide range of representative classes of standard and new olefinic substrates such as dehydroamido esters
一系列对映纯的P-立体异构1,2-双[(o -RO-苯基)(苯基)膦基]乙烷(R-SMS-Phos)配体,其中R = i -Pr,i -Bu,t -Bu,3 -苯和CH 2 TMS是在Rh(I)催化的一组指示性烯烃的氢化反应中评估的。表现最佳吨-Bu-SMS-PHOS配体筛选对宽范围的代表类标准和新的烯烃底材如dehydroamido酯,脱氢α酰氨基膦酸酯,烯酰胺,衣康酸酯,丙烯酸酯,乙烯醇的,α-苯甲酸磷新戊酯,α-(2-吡啶基N-氧化物)苯乙烯和α-(1-羟亚氨基乙基)苯乙烯。在温和的条件下可获得出色的对映选择性和高TOF。
Impact on Hydrogenation Catalytic Cycle of the R Groups’ Cyclic Feature in “R-SMS-Phos”
作者:Borut Zupančič、Barbara Mohar、Michel Stephan
DOI:10.1021/ol101029s
日期:2010.7.2
A series of R-SMS-Phos ligands was evaluated in the Rh(I)-catalyzed hydrogenation of a set of olefins showing a marked influence of the cyclic nature and structure of the R groups. Overall, cPen- and Cy-SMS-Phos performed efficiently, while Ph- and Bn-SMS-Phos exhibited slower kinetics and furnished lower ee's also compared with C6F5CH2-SMS-Phos. The Rh(I)-(Cy-SMS-Phos) catalyst was screened under mild conditions displaying excellent enantioselectivities and high TOFs. Cases of catalysis under catalyst or substrate control were identified.
Rhodium-Catalyzed Enantioselective Hydrogenation of β-Phthalimide Acrylates to Synthesis of β<sup>2</sup>-Amino Acids
[Structure: see text] The enantioselectivehydrogenation of beta-phthalimide acrylates provides the corresponding chiral beta2-amino acids in excellent enantiomeric excess catalyzed by Rh-monophosphorus.