Enantioselective Synthesis of Sterically Hindered Tertiary α-Aryl Oxindoles via Palladium-Catalyzed Decarboxylative Protonation. An Experimental and Theoretical Mechanistic Investigation

Maria Biosca; Mark Jackson; Marc Magre; Oscar Pàmies; Per-Ola Norrby; Montserrat Diéguez; Patrick J. Guiry

doi:10.1002/adsc.201800507

Enantioselective Synthesis of Sterically Hindered Tertiary α-Aryl Oxindoles via Palladium-Catalyzed Decarboxylative Protonation. An Experimental and Theoretical Mechanistic Investigation

Advanced Synthesis & Catalysis ◽

10.1002/adsc.201800507 ◽

2018 ◽

Vol 360 (16) ◽

pp. 3124-3137 ◽

Cited By ~ 6

Author(s):

Maria Biosca ◽

Mark Jackson ◽

Marc Magre ◽

Oscar Pàmies ◽

Per-Ola Norrby ◽

...

Keyword(s):

Enantioselective Synthesis ◽

Mechanistic Investigation ◽

Palladium Catalyzed ◽

Sterically Hindered

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Theoretical and experimental studies of palladium-catalyzed site-selective C(sp3)−H bond functionalization enabled by transient ligands

10.26434/chemrxiv.5717950 ◽

2017 ◽

Author(s):

Haibo Ge ◽

Lei Pan ◽

Piaoping Tang ◽

Ke Yang ◽

Mian Wang ◽

...

Keyword(s):

Bond Activation ◽

Theoretical Calculations ◽

Experimental Studies ◽

Bond Functionalization ◽

Aliphatic Ketones ◽

Site Selectivity ◽

Mechanistic Investigation ◽

Palladium Catalyzed ◽

Metal Catalyzed ◽

Site Selective

Transition metal-catalyzed selective C–H bond functionalization enabled by transient ligands has become an extremely attractive topic due to its economical and greener characteristics. However, catalytic pathways of this reaction process on unactivated sp3 carbons of reactants have not been well studied yet. Herein, detailed mechanistic investigation on Pd-catalyzed C(sp3)–H bond activation with amino acids as transient ligands has been systematically conducted. The theoretical calculations showed that higher angle distortion of C(sp2)-H bond over C(sp3)-H bond and stronger nucleophilicity of benzylic anion over its aromatic counterpart, leading to higher reactivity of corresponding C(sp3)–H bonds; the angle strain of the directing rings of key intermediates determines the site-selectivity of aliphatic ketone substrates; replacement of glycine with β-alanine as the transient ligand can decrease the angle tension of the directing rings. Synthetic experiments have confirmed that β-alanine is indeed a more efficient transient ligand for arylation of β-secondary carbons of linear aliphatic ketones than its glycine counterpart.

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

Current Organic Chemistry ◽

10.2174/1385272823666190624145039 ◽

2019 ◽

Vol 23 (11) ◽

pp. 1168-1213 ◽

Cited By ~ 4

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.

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