Metal‐Catalyzed Sequential Formation of Distant Bonds in Organic Molecules: Palladium‐Catalyzed Hydrosilylation/Cyclization of 1, n ‐Dienes by Chain Walking

2019 ◽  
Vol 58 (16) ◽  
pp. 5261-5265 ◽  
Author(s):  
Takuya Kochi ◽  
Kazuya Ichinose ◽  
Masayuki Shigekane ◽  
Taro Hamasaki ◽  
Fumitoshi Kakiuchi
2019 ◽  
Vol 131 (16) ◽  
pp. 5315-5319 ◽  
Author(s):  
Takuya Kochi ◽  
Kazuya Ichinose ◽  
Masayuki Shigekane ◽  
Taro Hamasaki ◽  
Fumitoshi Kakiuchi

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>


Synthesis ◽  
2020 ◽  
Vol 53 (02) ◽  
pp. 238-254
Author(s):  
Fulin Zhang ◽  
Luoting Xin ◽  
Saihu Liao ◽  
Xueliang Huang ◽  
Yinghua Yu

AbstractTransition-metal-catalyzed direct inert C–H bond functionalization has attracted much attention over the past decades. However, because of the high strain energy of the suspected palladacycle generated via C–H bond palladation, direct functionalization of a C–H bond less than a three-bond distance from a catalyst center is highly challenging. In this short review, we summarize the advances on palladium-catalyzed bridging C–H activation, in which an inert proximal C–H bond palladation is promoted by the elementary step of migratory insertion of an alkene, an alkyne or a metal carbene intermediate.1 Introduction2 Palladium-Catalyzed Alkene Bridging C–H Activation2.1 Intramolecular Reactions2.2 Intermolecular Reactions3 Palladium-Catalyzed Alkyne Bridging C–H Activation3.1 Intermolecular Reactions3.2 Intramolecular Reactions4 Palladium-Catalyzed Carbene Bridging C–H Activation5 Conclusion and Outlook


2002 ◽  
Vol 74 (8) ◽  
pp. 1327-1337 ◽  
Author(s):  
Irina P. Beletskaya

The palladium-catalyzed substitution reactions forming carbon­carbon and carbon­element bonds, as well as nickel-catalyzed addition of E­H and E­E' bonds across multiple bonds, are considered in their application to the chemistry of heterocyclic compounds.


Synthesis ◽  
2017 ◽  
Vol 49 (12) ◽  
pp. 2589-2604 ◽  
Author(s):  
Kristen Gettys ◽  
Zhishi Ye ◽  
Mingji Dai

Piperazine ranks as the third most common N-heterocycle appearing in small-molecule pharmaceuticals. This review highlights recent advances in methods development for the construction of the piperazine­ ring system with particular emphasis on preparing carbon-substituted piperazines.1 Introduction2 Reduction of (Di)ketopiperazine3 N-Alkylation4 Transition-Metal-Catalyzed/Mediated Piperazine Synthesis4.1 The SnAP and SLAP Methods4.2 Palladium-Catalyzed Cyclization4.3 Gold-Catalyzed Cyclization4.4 Other Metal-Catalyzed/Mediated Cyclization4.5 Borrowing Hydrogen Strategy4.6 Imine Reductive Cyclization5 Reduction of Pyrazines6 Miscellaneous7 Conclusion


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