Asymmetric Reactions Catalyzed by Chiral Metal Complexes. XLV. Efficient Preparation of Optically Active (S)-(-)-3-Methyl-.GAMMA.-butyrolactone by Catalytic Asymmetric Hydrogenation Using Chiral N-Substituted Pyrrolidinebisphosphine Rhodium Complexes.
(S)-(-)-2-Methyl succinamic acid, which is a good precursor of (S)-(-)-3-methyl-γ-butyrolactone, can be prepared by homogeneous asymmetric hydrogenation of 2-methylene succinamic acid catalyzed by (2S, 4S)-N-substituted-4-(diphenylphosphino)-2-[(diphenylphosphino)-methyl]pyrrolidine-rhodium complexes. Various N-substituted pyrrolidine-bisphosphines were synthesized to find the optimum ligand for this purpose and to compare the effects of the N-substituents.
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。
DiPAMPâs Big Brother â<i>i-</i>Pr-SMS-Phosâ Exhibits Exceptional Features Enhancing Rhodium(I)-Catalyzed Hydrogenation of Olefins
作者:Michel Stephan、Damjan SÌterk、Barbara Mohar
DOI:10.1002/adsc.200900621
日期:2009.11
Switching Knowles DiPAMP’s DiPAMP=1,2-bis[(o-anisyl)(phenyl)phosphino]-ethane} MeO groups with i-PrO ones led to the i-Pr-SMS-Phos i-Pr-SMS-Phos=1,2-bis[(o-isoprop- oxyphenyl)(phenyl)phosphino]ethane} ligand which displayed a boosted catalyst activity coupled with an enhanced enantioselectivity in the rhodium(I)-catalyzed hydrogenation of a wide-range of representative olefinic substrates (dehydro-α-amido
Modular 1,1′-Ferrocenediyl-cored <i>P</i>
-Stereogenic Diphosphines: ′′JDayPhos′′ Series and its Use in Rhodium(I)-Catalyzed Hydrogenation
作者:Gašper Poklukar、Michel Stephan、Barbara Mohar
DOI:10.1002/adsc.201800255
日期:2018.7.4
A novel ferrocene‐based P‐stereogenic diphospine ligand series dubbed JDayPhos was developed, which rhodium(I) complexes of some of its members exhibited excellent enantioselectivity (up to >99% ee) and high activity in asymmetric hydrogenation of β‐unsubstituted or ‐substituted itaconates and α‐methylene‐γ‐oxo‐carboxylates.
Highly Efficient Asymmetric Hydrogenation of 2-Methylenesuccinamic Acid Using a Rh-DuPHOS Catalyst
作者:Christopher J. Cobley、Ian C. Lennon、Céline Praquin、Antonio Zanotti-Gerosa、Robert B. Appell、Christian T. Goralski、Angela C. Sutterer
DOI:10.1021/op0256183
日期:2003.5.1
An extremely efficient route to highly enantiomerically enriched 2-methylsuccinamic acid via asymmetrichydrogenation has been developed. By using [(S,S)-Et-DuPHOS Rh COD]BF4 as the precatalyst und...