Synthesis of epimer of Taniaphos ligand

Almássy, Ambroz; Rakovský, Erik; Malastová, Andrea; Sorádová, Zuzana; Šebesta, Radovan

doi:10.1016/j.jorganchem.2016.01.004

Cited by 8 publications

(2 citation statements)

References 45 publications

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“…This observation then led us to the synthesis of epimeric Taniaphos ligand via stepwise lithiation/phosphylation. 31 The synthesis was based on the realization that Br/Li exchange can be selectively performed at lower temperature and then the ferrocene ortho -lithiation can be accomplished with pro- R p diastereoselectivity (Scheme 3b ). Intrigued by these questions, we have investigated several typical ortho -lithiations using DFT calculations.…”

Section: Base-mediated Ortho -Deprotonationsmentioning

confidence: 99%

Comparison of Diastereoselective ortho-Metalations and C–H Activations of Chiral Ferrocenes

Čarný¹,

Šebesta²

2023

Synlett

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Chiral ferrocene derivatives possessing planar stereogenic unit are important as chiral catalysts or materials. The principled method to obtain 1,2-disubstituted planarly chiral ferrocenes was base-mediated ortho-metalation performed on a chiral ferrocene derivative, typically using organolithium bases. A multitude of chiral ligands and other useful compounds was synthesized using this methodology. Newer methodology employing transition-metal catalyzed C-H bond activation strategies complements ortho-metalation methods and affords access to different types of planar chiral ferrocene derivatives.

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Section: Base-mediated Ortho -Deprotonationsmentioning

confidence: 99%

Comparison of Diastereoselective ortho-Metalations and C–H Activations of Chiral Ferrocenes

Čarný¹,

Šebesta²

2023

Synlett

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“…Among the recently developed numerous chiral ligands for the transition‐metal based chiral reduction catalysts; C 2 ‐symmetric ferrocenyl phosphinites are notable. In particular chiral ferrocenyl phosphinites or phosphanes possessing C 2 ‐ symmetric structure represent an important class of ligands used in homogeneous asymmetric catalysis with transition metals …”

Section: Introductionmentioning

confidence: 99%

Ferrocene based chiral binuclear η⁶‐benzene‐Ru(II)‐phosphinite complexes: Synthesis, characterization and catalytic activity in asymmetric reduction of ketones

Al-bayati

Karakaş

Meri̇ç

et al. 2017

Applied Organom Chemis

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In the present study, a series of chiral C 2 -symmetric ferrocenyl based binuclear η 6 -benzene-Ru(II) complexes bearing diphenylphosphinite and diisopropylphosphinite moieties have been synthesised. The new binuclear η 6 -benzene-Ru(II)-phosphinite complexes were characterised based on nuclear magnetic resonance ( 1 H, 13 C, 31 P-NMR), FT-IR spectroscopy and elemental analysis. Then, these complexes have been screened as catalytic precursors in the transfer hydrogenation of acetophenone with 2-propanol as both the hydrogen source and solvent in the presence of KOH. The corresponding optically active secondary alcohols were obtained in excellent conversion rates between 96 and 99% and moderate to good enantioselectivities (up to 78% ee). The complex 5 was the most efficient catalyst among the four new complexes investigated herein. | INTRODUCTIONAsymmetric catalysis plays a vital role in generating single enantiomeric materials. The development of more efficient methodologies in asymmetric catalysis is a very important area of research in organic chemistry. [1] The optically pure secondary alcohols are important class of intermediates for the fine chemicals especially pharmaceutical, [2] agrochemical, [3] cosmetic, food, and flavour industries. [4] The catalytic reduction of pro-chiral ketones to chiral secondary alcohols by using transfer hydrogenation can be considered an attractive method compared with the common reduction processes which involve hazardous reducing reagents or high hydrogen pressure. [5] Simple equipment, atom economy, low catalyst loading, safe manipulation, high selectivity, environmentally friendly solvents and contribution to industrial applications are key advantages of transfer hydrogenation. [6] An increasing number of chiral compounds and optically pure secondary alcohols are prepared through transition metal-catalysed asymmetric reactions. A number of transition metal complexes are known to be used in asymmetric transfer hydrogenation (ATH) reactions as catalysts. [6] Most often, chiral ligand bearing Ru(II) [7] , Rh(I) [8] and Ir(III) [9] complexes have received great attention due to their exclusive applications in asymmetric transfer hydrogenation. The catalysts used in this reaction are often Ru(II) complexes, especially half-sandwich Ru(II) complexes. [10] Despite being stable and easy to prepare, half-sandwich Ru(II) complexes [RuCl 2 (η 6 -arene)(L)], where L is a chiral monodentate phosphinite ligand, have been rarely used in asymmetric transfer hydrogenation.Numerous chiral ligands with aminoalcohols, [11] diamines, [12] sulphur containing ligands, [13] phosphorus containing ligands (phosphine, [14] phosphinite, [15] phosphite [16] etc.), heterocyclic ligands [17] and ferrocenyl backbones [18] have been designed, synthesised and used successfully in a variety of catalytic applications. Among the recently developed numerous chiral ligands for the

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TANIAPHOS, taniaphos

Eppinger¹

2020

Catalysis From a to Z

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Synthesis of epimer of Taniaphos ligand

Cited by 8 publications

References 45 publications

Comparison of Diastereoselective ortho-Metalations and C–H Activations of Chiral Ferrocenes

Comparison of Diastereoselective ortho-Metalations and C–H Activations of Chiral Ferrocenes

Ferrocene based chiral binuclear η⁶‐benzene‐Ru(II)‐phosphinite complexes: Synthesis, characterization and catalytic activity in asymmetric reduction of ketones

TANIAPHOS, taniaphos

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Synthesis of epimer of Taniaphos ligand

Cited by 8 publications

References 45 publications

Comparison of Diastereoselective ortho-Metalations and C–H ­Activations of Chiral Ferrocenes

Comparison of Diastereoselective ortho-Metalations and C–H ­Activations of Chiral Ferrocenes

Ferrocene based chiral binuclear η6‐benzene‐Ru(II)‐phosphinite complexes: Synthesis, characterization and catalytic activity in asymmetric reduction of ketones

TANIAPHOS, taniaphos

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Comparison of Diastereoselective ortho-Metalations and C–H Activations of Chiral Ferrocenes

Comparison of Diastereoselective ortho-Metalations and C–H Activations of Chiral Ferrocenes

Ferrocene based chiral binuclear η⁶‐benzene‐Ru(II)‐phosphinite complexes: Synthesis, characterization and catalytic activity in asymmetric reduction of ketones