Catalytic Michael Reactions of Ketoesters with a Camphor-Derived Acrylate Equivalent: Stereoselective Access to All-Carbon Quaternary Centers

A metal- and catalyst-free photoinduced radical cascade hydroalkylation of 1,7-enynes has been disclosed. The process is triggered by a SET event involving a photoexcited electron-donor-aceptor complex between NHPI ester and Hantzsch ester, which decomposes to afford a tertiary radical that is readily trapped by the enyne. <a>The method provides an operationally simple, robust and step-economical approach to the construction of diversely functionalized dihydroquinolinones bearing quaternary-centers. A sequential one-pot hydroalkylation-isomerization approach is also allowed giving access to a family of quinolinones. A wide substrate scope and high functional group tolerance was observed in both approaches</a>.

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Diverse Cyclopentenes via Enantioselective Cu-Catalyzed Desymmetrization

10.26434/chemrxiv.6894833.v1 ◽

2018 ◽

Author(s):

Reece Jacques ◽

Robert D. C. Pullin ◽

Stephen P. Fletcher

Keyword(s):

Ring Systems ◽

Quaternary Centers ◽

Stereogenic Centers

<div> <div> <div> <p>A highly regio-, diastereo- and enantioselective Cu-catalyzed desymmetrization of diverse meso-bisphosphates with alkyl zirconium nucleophiles has been developed. The reaction allows access to a broad range of functionalized cyclopentenes with up to three contiguous stereogenic centers, including quaternary centers and spirocyclic ring systems.</p></div></div></div>

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Diverse Cyclopentenes via Enantioselective Cu-Catalyzed Desymmetrization

10.26434/chemrxiv.6894833 ◽

2018 ◽

Author(s):

Reece Jacques ◽

Robert D. C. Pullin ◽

Stephen P. Fletcher

Keyword(s):

Ring Systems ◽

Quaternary Centers ◽

Stereogenic Centers

<div> <div> <div> <p>A highly regio-, diastereo- and enantioselective Cu-catalyzed desymmetrization of diverse meso-bisphosphates with alkyl zirconium nucleophiles has been developed. The reaction allows access to a broad range of functionalized cyclopentenes with up to three contiguous stereogenic centers, including quaternary centers and spirocyclic ring systems.</p></div></div></div>

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Synthesis of Nitrile-Bearing Quaternary Centers via an Equilibrium-Driven Transnitrilation and Anion-Relay Strategy

10.26434/chemrxiv.7834940 ◽

2019 ◽

Author(s):

Sebastien Alazet ◽

Michael West ◽

Purvish Patel ◽

Sophie Rousseaux

Keyword(s):

Building Blocks ◽

One Pot ◽

Quaternary Centers ◽

Synthetic Intermediates

The efficient preparation of nitrile-containing building blocks is of interest due to their utility as synthetic intermediates and their prevalence in pharmaceuticals. As a result, significant efforts have been made to develop methods to access these motifs which rely on safer and non-toxic sources of CN. Herein, we report that 2-methyl-2-phenylpropanenitrile is an efficient, non-toxic, electrophilic CN source for the synthesis of nitrile-bearing quaternary centers via a thermodynamic transnitrilation and anion-relay strategy. This one-pot process leads to nitrile products resulting from the gem-difunctionalization of alkyl lithium reagents.<br>

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Enantioselective Michael Addition of Malonates to Enones

Current Organic Chemistry ◽

10.2174/1385272824666200316122221 ◽

2020 ◽

Vol 24 (7) ◽

pp. 746-773

Author(s):

Péter Bakó ◽

Tamás Nemcsok ◽

Zsolt Rapi ◽

György Keglevich

Keyword(s):

Michael Addition ◽

Activity Relationship ◽

Chalcone Derivatives ◽

Michael Additions ◽

Michael Reactions ◽

Structure Activity ◽

Cyclic Enones ◽

Michael Acceptors ◽

Relationship Of ◽

Enantioselective Catalysts

: Many catalysts were tested in asymmetric Michael additions in order to synthesize enantioenriched products. One of the most common reaction types among the Michael reactions is the conjugated addition of malonates to enones making it possible to investigate the structure–activity relationship of the catalysts. The most commonly used Michael acceptors are chalcone, substituted chalcones, chalcone derivatives, cyclic enones, while typical donors may be dimethyl, diethyl, dipropyl, diisopropyl, dibutyl, di-tert-butyl and dibenzyl malonates. This review summarizes the most important enantioselective catalysts applied in these types of reactions.

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Expedient Dual Co/Organophotoredox Catalyzed Stereoselective Synthesis of All‐Carbon Quaternary Centers

Angewandte Chemie ◽

10.1002/ange.202103479 ◽

2021 ◽

Author(s):

Alex Cristofol ◽

Bart Limburg ◽

Arjan Willem Kleij

Keyword(s):

Stereoselective Synthesis ◽

Quaternary Centers

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Synthesis and Catalytic Activities of 3-Decyl-β-proline for Michael Reactions in Water without an Organic Solvent

ACS Omega ◽

10.1021/acsomega.1c02289 ◽

2021 ◽

Author(s):

Kazuhiro Nagata ◽

Chihiro Nakagawa ◽

Wakana Yokoyama ◽

Haruka Usui ◽

Rikako Mochizuki ◽

...

Keyword(s):

Organic Solvent ◽

Catalytic Activities ◽

Michael Reactions

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Rhodium-catalyzed enone carbonyl directed C–H activation for the synthesis of indanones containing all-carbon quaternary centers

Organic Chemistry Frontiers ◽

10.1039/d1qo00056j ◽

2021 ◽

Vol 8 (7) ◽

pp. 1447-1453

Author(s):

Jiang Lou ◽

Wenjia Han ◽

Zhuqing Liu ◽

Jiaqi Xiao

Keyword(s):

Diazo Compounds ◽

Quaternary Centers ◽

Ketene Dithioacetals

Rhodium(iii)-catalyzed enone carbonyl directed C–H activation/annulation of α-aroyl ketene dithioacetals with diazo compounds has been realized for the synthesis of β-quaternary indanones.

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