Ligand Control of Palladium‐Catalyzed Site‐Selective α‐ and γ‐Arylation of α,β‐Unsaturated Ketones with (Hetero)aryl Halides

2020 ◽  
Vol 132 (52) ◽  
pp. 23644-23650
Author(s):  
On Ying Yuen ◽  
Chau Ming So
Synlett ◽  
2017 ◽  
Vol 29 (06) ◽  
pp. 754-758 ◽  
Author(s):  
Takanori Matsuda ◽  
Takeshi Matsumoto ◽  
Akira Murakami

A palladium(0)-catalyzed ring-opening cross-coupling reaction between tert-cyclobutenols and aryl halides produces γ-arylated β,γ-unsaturated ketones. In the case of aryl halides bearing functional groups at the ortho position, the resulting ring-opened ketones undergo intramolecular condensation to afford bicyclic aromatic compounds.


Synthesis ◽  
2018 ◽  
Vol 51 (06) ◽  
pp. 1455-1465 ◽  
Author(s):  
Li-ming Shao ◽  
Yi-lin Zheng ◽  
Li Xiao ◽  
Qiong Xie

We herein describe a versatile palladium-catalyzed synthesis of β,β-diaryl α,β-unsaturated ketones. A broad range of aryl halides react with β-arylbutanones to afford biologically useful, symmetrical and unsymmetrical ketones. The use of 4,5-diazafluoren-9-one and oxygen makes this one-pot reaction more applicable. A plausible mechanism involving palladium-catalyzed oxidative Heck-type cross-coupling is also proposed.


2017 ◽  
Author(s):  
Haibo Ge ◽  
Lei Pan ◽  
Piaoping Tang ◽  
Ke Yang ◽  
Mian Wang ◽  
...  

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 sp<sup>3</sup> carbons of reactants have not been well studied yet. Herein, detailed mechanistic investigation on Pd-catalyzed C(sp<sup>3</sup>)–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(sp<sup>3</sup>)–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.<br><br>


Author(s):  
Zhuang Qi ◽  
Shan‐Shan Li ◽  
Lin Li ◽  
Qi Qin ◽  
Li‐Miao Yang ◽  
...  

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