Enantioselective Synthesis of Optically Active 3,3-Diarylpropanoates by Conjugate Hydrosilylation with Chiral Rh-bis(oxazolinyl)phenyl Catalysts

Abstract

Conjugate hydrosilylation of 3,3-diarylacrylate derivatives catalyzed by chiral rhodium-bis(oxazolinyl)phenyl complexes (1 mol %) at 60 °C for 2 h was investigated to prepare optically active 3,3-diarylpropanoate derivatives in high yields up to 99% yield and high enantioselectivities up to 99%.

Highly Recyclable Chemo‐/Biocatalyzed Cascade Reactions with Ionic Liquids: One‐Pot Synthesis of Chiral Biaryl Alcohols

“…Thus far, methods for the asymmetric synthesis of chiral β,β‐diarylpropionic acids often involve a multistep sequence and/or stoichiometric transformation using chiral auxiliaries,2 only a few examples of catalytic asymmetric methods, including Rh I ‐ or Cu II ‐catalyzed reduction of β,β‐diaryl unsaturated acrylates3, 4 or nitriles5 using either polymethylhydrosiloxanes or diethoxymethylsilane as the reductants, and Rh I ‐catalyzed 1,4‐addition of organoboron reagents to arylidene Meldrum’s acids,6 have been reported to provide the corresponding β,β‐diaryl propanoates or propanenitriles with good to high enantioselectivities. In terms of atom economy and environmental concerns, asymmetric hydrogenation of β,β‐diarylacrylates with molecular H 2 is more advantageous.…”

Rhodium(I)‐Catalyzed Enantioselective Hydrogenation of Substituted Acrylic Acids with Sterically Similar β,β‐Diaryls

“…[1e] Thus far, methods for the asymmetric synthesis of chiral b,b-diarylpropionic acids often involve a multistep sequence and/or stoichiometric transformation using chiral auxiliaries, [2] only a few examples of catalytic asymmetric methods, including Rh I -or Cu II -catalyzed reduction of b,b-diaryl unsaturated acrylates [3,4] or nitriles [5] using either polymethylhydrosiloxanes or diethoxymethylsilane as the reductants, and Rh I -catalyzed 1,4-addition of organoboron reagents to arylidene Meldrums acids, [6] have been reported to provide the corresponding b,b-diaryl propanoates or propanenitriles with good to high enantioselectivities. [1e] Thus far, methods for the asymmetric synthesis of chiral b,b-diarylpropionic acids often involve a multistep sequence and/or stoichiometric transformation using chiral auxiliaries, [2] only a few examples of catalytic asymmetric methods, including Rh I -or Cu II -catalyzed reduction of b,b-diaryl unsaturated acrylates [3,4] or nitriles [5] using either polymethylhydrosiloxanes or diethoxymethylsilane as the reductants, and Rh I -catalyzed 1,4-addition of organoboron reagents to arylidene Meldrums acids, [6] have been reported to provide the corresponding b,b-diaryl propanoates or propanenitriles with good to high enantioselectivities.…”

“…[3][4][5][6][7][8] Very recently, we disclosed that Rh I catalysts generated in situ by interaction with SPO preligands demonstrated excellent performance in the asymmetric hydrogenation of a-substituted ethenylphosphonic acids. [3][4][5][6][7][8] Very recently, we disclosed that Rh I catalysts generated in situ by interaction with SPO preligands demonstrated excellent performance in the asymmetric hydrogenation of a-substituted ethenylphosphonic acids.…”

Rhodium(I)‐Catalyzed Enantioselective Hydrogenation of Substituted Acrylic Acids with Sterically Similar β,β‐Diaryls

“…

Dedicated to Professor Guo-Qiang Lin on the occasion of his 70th birthday Optically active b,b-diarylpropionic acids are a class of important building blocks for the asymmetric synthesis of chiral diarylmethine compounds, [1] which are structural moieties that are found in many pharmaceuticals and bioactive compounds, including the therapeutically important molecules tolterodine, [1a-b] sertraline, [1c] indatraline, [1d] and natural products, such as cherylline. [1e] Thus far, methods for the asymmetric synthesis of chiral b,b-diarylpropionic acids often involve a multistep sequence and/or stoichiometric transformation using chiral auxiliaries, [2] only a few examples of catalytic asymmetric methods, including Rh I -or Cu II -catalyzed reduction of b,b-diaryl unsaturated acrylates [3,4] or nitriles [5] using either polymethylhydrosiloxanes or diethoxymethylsilane as the reductants, and Rh I -catalyzed 1,4-addition of organoboron reagents to arylidene Meldrums acids, [6] have been reported to provide the corresponding b,b-diaryl propanoates or propanenitriles with good to high enantioselectivities. In terms of atom economy and environmental concerns, asymmetric hydrogenation of b,b-diarylacrylates with molecular H 2 is more advantageous.

…”

“…The most challenging issue associated with the control of stereochemistry in the asymmetric hydrogenation of b,bdiarylacrylic acids is the differentiation of a stereogenic center with two sterically similar aryl groups at the b-position of acrylic acids. [3][4][5][6][7][8] Very recently, we disclosed that Rh I catalysts generated in situ by interaction with SPO preligands demonstrated excellent performance in the asymmetric hydrogenation of a-substituted ethenylphosphonic acids. [9] The salient features of SPO ligands, including ready accessibility, good air and moisture stability, and the potentially H-bonding OH group in the ligand, [9,10] prompted us to explore the catalytic potential of Rh I /SPO systems in the asymmetric hydrogenation of challenging b,b-diarylacrylic acid substrates.…”