Copper(<scp>I</scp>)<i>‐</i>Catalyzed Asymmetric Hydrosilylations of Imines at Ambient Temperatures

Lipshutz, Bruce H.; Shimizu, Hideo

doi:10.1002/anie.200353294

Cited by 193 publications

(66 citation statements)

References 24 publications

(13 reference statements)

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“…In contrast to the stoichiometric reaction which proceeded at −78 °C to provide 15 in nearly quantitative yield (entries 1, 5, 9), the catalytic reactions did not proceed readily at −78 °C. With 0.1 equiv of ligand for the addition of MeLi, the yields of 15 were only 27-46% (entries 4, 8,12). Interestingly, the enantioselectivities decreased only slightly as the amount of ligand decreased.…”

Section: Catalytic Reactionsmentioning

confidence: 99%

Studies on the Bisoxazoline‐ and (−)‐Sparteine‐Mediated Enantioselective Addition of Organolithium Reagents to Imines

et al. 2008

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The enantioselective addition of organolithium reagents to N-anisyl aldimines promoted by chiral bisoxazolines and (−)-sparteine as external ligands is described. This reaction proceeds readily with a wide range of aldimine substrates (aliphatic, aromatic, olefinic) and organolithium nucleophiles (Me, n-Bu, Ph, vinyl) in excellent yields (81-99%) and with high enantioselectivities (up to 95.5:4.5 er). The external ligands can be used in substoichiometric amounts albeit with slightly attenuated enantioselectivities. A systematic evaluation of the structural features of the bisoxazolines revealed a primary contribution from the substituent at C(4) and a secondary influence from the bridging substituents. A computational analysis (PM3) provided a clear rationalization for the origin of enantioselectivity.

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Section: Catalytic Reactionsmentioning

confidence: 99%

Studies on the Bisoxazoline‐ and (−)‐Sparteine‐Mediated Enantioselective Addition of Organolithium Reagents to Imines

et al. 2008

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“…2 While a number of metal complexes of Ti, 3 Rh, 4 Ru, 5 Cu, 6 and Re 7 were employed for enantioselective hydrosilylation of prochiral imines, we reported recently the first highly enantioselective hydrosilylation of imines catalyzed by a chiral diamine-zinc catalyst.…”

Section: Introductionmentioning

confidence: 99%

Enantioselective Hydrosilylation of Imines Catalyzed by Diamine-Zinc Complexes

Park¹,

Feng²,

Yun

2011

Bulletin of the Korean Chemical Society

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The efficient asymmetric hydrosilylation of imines in the presence of polymethylhydrosiloxane has been investigated by screening chiral diamine-zinc complexes. A series of chiral diamine ligands were prepared from optically pure 1,2-diphenyl-1,2-ethanediamine and screened for effectiveness. N-Benzylic substituents were required for high enantioselectivity; ligands with bulky groups or extra coordinating groups such as OH and S lowered the catalytic activity. The level of asymmetric induction was usually in >90% ee range for aromatic imine substrates. A linear correlation between the ee of the ligand and that of the product was observed, indicating the presence of a 1:1 ratio of ligand to metal coordination in the active catalytic complex.

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“…N-phosphinyl imines have found a variety of synthetic applications in asymmetric processes [10,24,25]. For instance, the preparation of chiral amines can be achieved by stereoselective reduction of N-phosphinyl ketimines through different synthetic approaches such as hydrogenation [26][27][28], hydrosilylation [29][30][31][32][33], Meerwein-Schmidt-PonndorfVerley (MSPV) reaction [34] or the use of boron [35] and aluminium hydrides [36].…”

Section: Open Accessmentioning

confidence: 99%

“…N-(1-Phenylethylidene)diphenylphosphinamide (1a) [29]: pale yellow solid; mp 120-122 °C; IR (KBr) 3064, 1637, 1192 cm …”

Section: Procedures For the Preparation Of N-phosphinyliminesmentioning

confidence: 99%

Chiral β-Amino Alcohols as Ligands for the Ruthenium-Catalyzed Asymmetric Transfer Hydrogenation of N-Phosphinyl Ketimines

2012

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Some chiral β-amino alcohols have been evaluated as potential ligands for the ruthenium-catalyzed asymmetric transfer hydrogenation (ATH) of N-phosphinyl ketimines in isopropyl alcohol. The ruthenium complex prepared from [RuCl 2 (p-cymene)] 2 and (1S,2R)-1-amino-2-indanol has shown to be an efficient catalyst for the ATH of several N-(diphenylphosphinyl)imines, affording the reduction products in very good isolated yields and enantiomeric excesses up to 82%. The inherent rigidity of the indane ring system present in the ligand seems to be very important to achieve good enantioselectivities.

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Copper(I)‐Catalyzed Asymmetric Hydrosilylations of Imines at Ambient Temperatures

Cited by 193 publications

References 24 publications

Studies on the Bisoxazoline‐ and (−)‐Sparteine‐Mediated Enantioselective Addition of Organolithium Reagents to Imines

Studies on the Bisoxazoline‐ and (−)‐Sparteine‐Mediated Enantioselective Addition of Organolithium Reagents to Imines

Enantioselective Hydrosilylation of Imines Catalyzed by Diamine-Zinc Complexes

Chiral β-Amino Alcohols as Ligands for the Ruthenium-Catalyzed Asymmetric Transfer Hydrogenation of N-Phosphinyl Ketimines

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