Sulfur–imine mixed donor chelate ligands for asymmetric catalysis: enantioselective allylic alkylation

1998 ◽  
Vol 9 (5) ◽  
pp. 753-756 ◽  
Author(s):  
James C. Anderson ◽  
Daniel S. James ◽  
John P. Mathias
Keyword(s):  
Asymmetric Catalysis ◽  
Allylic Alkylation ◽  
Chelate Ligands

Novel Chiral Ligands for Palladium-catalyzed Asymmetric Allylic Alkylation/ Asymmetric Tsuji-Trost Reaction: A Review

2019 ◽  
Vol 23 (11) ◽  
pp. 1168-1213 ◽  
Author(s):  
Samar Noreen ◽  
Ameer Fawad Zahoor ◽  
Sajjad Ahmad ◽  
Irum Shahzadi ◽  
Ali Irfan ◽  
...  
Keyword(s):  
Asymmetric Catalysis ◽  
Enantioselective Synthesis ◽  
Chiral Ligands ◽  
Allylic Alkylation ◽  
Research Groups ◽  
Asymmetric Allylic Alkylation ◽  
Catalytic Potential ◽  
Long Time ◽  
Palladium Catalyzed ◽  
Alkylation Reactions

Background: Asymmetric catalysis holds a prestigious role in organic syntheses since a long time and chiral inductors such as ligands have been used to achieve the utmost desired results at this pitch. The asymmetric version of Tsuji-Trost allylation has played a crucial role in enantioselective synthesis. Various chiral ligands have been known for Pdcatalyzed Asymmetric Allylic Alkylation (AAA) reactions and exhibited excellent catalytic potential. The use of chiral ligands as asymmetric inductors has widened the scope of Tsuji-Trost allylic alkylation reactions. Conclusion: Therefore, in this review article, a variety of chiral inductors or ligands have been focused for palladium catalyzed asymmetric allylic alkylation (Tsuji-Trost allylation) and in this regard, recently reported literature (2013-2017) has been described. The use of ligands causes the induction of enantiodiscrimination to the allylated products, therefore, the syntheses of various kinds of ligands have been targeted by many research groups to employ in Pd-catalyzed AAA reactions.

Preparation of Optically Activeα-Amino[3]ferrocenophanes− Building Blocks for Chelate Ligands in Asymmetric Catalysis

2003 ◽  
Vol 2003 (23) ◽  
pp. 4261-4261 ◽  
Author(s):  
Patrick Liptau ◽  
Ludger Tebben ◽  
Gerald Kehr ◽  
Birgit Wibbeling ◽  
Roland Fröhlich ◽  
...  
Keyword(s):  
Asymmetric Catalysis ◽  
Building Blocks ◽  
Chelate Ligands

Preparation of Optically Activeα-Amino[3]ferrocenophanes− Building Blocks for Chelate Ligands in Asymmetric Catalysis

2003 ◽  
Vol 2003 (19) ◽  
pp. 3590-3600 ◽  
Author(s):  
Patrick Liptau ◽  
Ludger Tebben ◽  
Gerald Kehr ◽  
Birgit Wibbeling ◽  
Roland Fröhlich ◽  
...  
Keyword(s):  
Asymmetric Catalysis ◽  
Building Blocks ◽  
Chelate Ligands

From Prochiral N-Heterocyclic Carbenes (NHC) to Optically Pure Copper Complexes: New Opportunities in Asymmetric Catalysis

2019 ◽  
Author(s):  
Lingyu Kong ◽  
Jennifer Morvan ◽  
Delphine Pichon ◽  
Marion Jean ◽  
Muriel Albalat ◽  
...  
Keyword(s):  
Asymmetric Catalysis ◽  
Copper Complexes ◽  
Pure Copper ◽  
Heterocyclic Carbenes ◽  
Allylic Alkylation ◽  
Chiral Hplc ◽  
Pure Cu ◽  
First Time ◽  
Optically Pure ◽  
Cu Complexes

Well-defined optically pure copper-complexes are obtained from prochiral N- Heterocyclic Carbene (NHC) ligands. As predicted by DFT calculations, our strategy capitalizes on the formation of a metal-carbene bond which induces axial chirality. Configurationally stable (Sa)- and (Ra)-atropisomers of various Cu-complexes are isolated by preparative chiral HPLC in nearly quantitative yields and excellent optical purities (>99.5%). Their catalytic performances are illustrated in asymmetric allylic alkylation with high regioselectivity and enantioinductions. Importantly, the carbene transfer from an optically pure Cu-complex to gold or palladium center reveals, for the first time, a full stereoretentivity, supporting the hypothesis of an associative mechanism for the transmetalation.

BINAPS - An axially chiral P,S-heterodonor ligand for asymmetric catalysis based on binaphthalene backbone

2001 ◽  
Vol 79 (5-6) ◽  
pp. 670-678 ◽  
Author(s):  
Serafino Gladiali ◽  
Serenella Medici ◽  
Giovanna Pirri ◽  
Sonia Pulacchini ◽  
Davide Fabbri
Keyword(s):  
Transition Metal ◽  
Asymmetric Catalysis ◽  
Hydrogen Transfer ◽  
Transition Metal Catalysts ◽  
Enantioselective Catalysis ◽  
Allylic Alkylation ◽  
Reaction Sequence ◽  
Axially Chiral ◽  
Pd Complexes ◽  
Multistep Reaction

The chelating P,S-heterodonor ligand 2-diphenylphosphanyl-1,1'-binaphthalene-2'-thiol (11) (BINAPS), which features a chiral axis as the unique stereogenic element, has been prepared in both racemic and enantiopure form through a multistep reaction sequence using 2,2'-dihydroxy-1,1'-binaphthalene (BINOL) as the starting material. The reaction sequence is completely stereoconservative and (S)-11 is obtained with no loss of enantiopurity from pure (S)-BINOL. (R)-11 can be alternatively obtained by resolution of racemic 11 using the chiral (S)-benzylaminato Pd(II)-complex 19 as the resolving agent. The S-methyl or the S-i-propyl derivatives 14 have been used as chiral ligands in the Rh(I)-catalyzed asymmetric hydroformylation of styrene and in the hydrogen transfer reduction of acetophenone with modest success (up to 20% ee). In the presence of suitable Pd-complexes the same ligands provide higher ees in the hydrosilylation of styrene (50% ee) and in the allylic alkylation of 1,3-diphenylprop-2-enyl acetate (60% ee).Key words: heterodonor ligands, binaphthalene derivatives, enantioselective catalysis, transition metal catalysts, allylic alkylation.

Exploring the utility of a new chiral phosphoramidite P,N-ligand derived from (R)-BINOL and 7-azaindole in asymmetric catalysis

2009 ◽  
Vol 87 (1) ◽  
pp. 72-79 ◽  
Author(s):  
Dominik Wechsler ◽  
Mark Stradiotto
Keyword(s):  
Asymmetric Catalysis ◽  
Platinum Group Metal ◽  
Allylic Alkylation ◽  
Chiral Ligand ◽  
Chemical Transformations ◽  
Group Metal ◽  
Alkene Hydrogenation ◽  
Platinum Group

Lithiation of 7-azaindole, followed by quenching with [(R)-(1,1′-binaphthalene-2,2′-diyl)]chlorophosphite afforded the new chiral phosphoramidite 1 in 92% isolated yield. Treatment of 0.5 equiv. of [(COD)MCl]2 (M = Rh, Ir; COD = η4-1,5-cyclooctadiene) with 2 equiv. of 1 afforded the corresponding [(κ1-P,N-1)(κ2-P,N-1)MCl] complexes in 68% (2a, Rh) and 72% (2b, Ir) yield, while treatment of (PPh3)3RhCl with 1 equiv. of 1 afforded [(PPh3)(κ2-P,N-1)RhCl] (3) as an analytically pure solid in 74% isolated yield. In examining the reaction of 1 with a mixture of 0.5 equiv. of [(COD)RhCl]2 and 1 equiv. of AgBF4, an inseparable mixture of [(κ2-P,N-1)2Rh]+BF4– (4a) and [(COD)(κ2-P,N-1)Rh]+BF4– (5a) was generated. Under analogous conditions employing [(COD)IrCl]2, the complex [(COD)(κ2-P,N-1)Ir]+BF4– (5b) was obtained in 86% isolated yield. Treatment of 0.5 equiv. of [(η3-allyl)PdCl]2 with 1 afforded [(η3-allyl)(κ2-P,N-1)Pd]+Cl– (6) in 86% isolated yield. The application of 1 in platinum group metal-mediated asymmetric chemical transformations, including alkene hydrogenation and hydroboration, ketone hydrosilylation, and allylic alkylation, was examined.Key words: chiral, ligand, phosphoramidite, asymmetric catalysis.

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