Late‐Stage Peptide Macrocyclization by Palladium‐Catalyzed Site‐Selective C−H Olefination of Tryptophan

2020 ◽  
Vol 59 (34) ◽  
pp. 14686-14692 ◽  
Author(s):  
Zengbing Bai ◽  
Chuangxu Cai ◽  
Wangjian Sheng ◽  
Yuxiang Ren ◽  
Huan Wang
Keyword(s):  
Late Stage ◽  
Palladium Catalyzed ◽  
Site Selective

Late‐Stage Peptide Macrocyclization by Palladium‐Catalyzed Site‐Selective C−H Olefination of Tryptophan

2020 ◽  
Vol 132 (34) ◽  
pp. 14794-14800
Author(s):  
Zengbing Bai ◽  
Chuangxu Cai ◽  
Wangjian Sheng ◽  
Yuxiang Ren ◽  
Huan Wang
Keyword(s):  
Late Stage ◽  
Palladium Catalyzed ◽  
Site Selective

scholarly journals Macrocyclization of peptidoarylacetamides with self-assembly properties through late-stage palladium-catalyzed C(sp2)▬H olefination

2019 ◽  
Vol 5 (3) ◽  
pp. eaaw0323 ◽  
Author(s):  
Jiantao Tan ◽  
Jie Wu ◽  
Shu Liu ◽  
Hequan Yao ◽  
Huan Wang
Keyword(s):  
Self Assembly ◽  
Late Stage ◽  
Cyclic Peptides ◽  
Cross Link ◽  
Selective Functionalization ◽  
Palladium Catalyzed ◽  
Material Sciences ◽  
Facile Preparation ◽  
Metal Catalyzed ◽  
Site Selective

Peptide macrocycles often display diverse bioactivities and self-assembly properties, which lead to a variety of applications in medicinal and material sciences. Transition metal–catalyzed C▬H activations are emerging strategies for site-selective functionalization of amino acids and peptides, as well as the construction of cyclic peptides. Here, we report the development of a peptide-directed method for the macrocyclization of peptidoarylacetamides by Pd(II)-catalyzed late-stage C(sp2)▬H olefination. In this protocol, peptide backbones act as internal directing groups and enable facile preparation of diverse cyclic peptides that are difficult to synthesize by conventional macrolactamization. Furthermore, we show that the incorporation of aryl-alkene cross-link in the backbone constrains cyclic peptides into conformations for self-assembly.

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

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 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>

Sequential C-Selective Difluoromethylation/Pd-Catalyzed Decarboxylative Protonation: An Efficient Access to Tertiary Difluoromethylated Scaffolds

2019 ◽  
Author(s):  
Nicolas Duchemin ◽  
Roberto Buccafusca ◽  
Marc Daumas ◽  
Vincent Ferey ◽  
Stellios Arseniyadis
Keyword(s):  
Drug Development ◽  
Late Stage ◽  
Efficient Access ◽  
Palladium Catalyzed ◽  
General Method

We report here a general method that allows a highly straightforward access to tertiary difluoromethylated compounds. The strategy relies on a two-step sequence featuring a C-selective electrophilic difluoromethylation and an unprecedented palladium-catalyzed decarboxylative protonation. Considering the generality of the method and the attractive properties offered by the difluoromethyl group, this approach provides a valuable tool for late-stage functionalization and drug development.<br>

Remote C–H Functionalizations by Ruthenium Catalysis

Synthesis ◽  
2021 ◽  
Author(s):  
Korkit Korvorapun ◽  
Ramesh C. Samanta ◽  
Torben Rogge ◽  
Lutz Ackermann
Keyword(s):  
Steric Hindrance ◽  
Late Stage ◽  
Crop Protection ◽  
Full Control ◽  
Site Selectivity ◽  
Important Approach ◽  
Distinct Character ◽  
Ruthenium Catalysis ◽  
Material Sciences ◽  
Site Selective

Synthetic transformations of otherwise inert C–H bonds have emerged as a powerful tool for molecular modifications during the last decades, with broad applications towards pharmaceuticals, material sciences and crop protection. Consistently, a key challenge in C–H activation chemistry is the full control of site-selectivity. In addition to substrate control through steric hindrance or kinetic acidity of C–H bonds, one important approach for the site-selective C–H transformation of arenes is the use of chelation-assistance through directing groups, therefore leading to proximity-induced ortho-C–H metalation. In contrast, more challenging remote C–H activations at the meta- or para-positions continue to be scarce. Within this review, we demonstrate the distinct character of ruthenium catalysis for remote C–H activations until March 2021, highlighting among others late-stage modifications of bio-relevant molecules. Moreover, we highlight important mechanistic insights by experiments and computation, highlighting the key importance of carboxylate-assisted C–H activation with ruthenium(II) complexes.

scholarly journals Palladium-Catalyzed Late-Stage Direct Arene Cyanation

Chem ◽  
2019 ◽  
Vol 5 (1) ◽  
pp. 97-107 ◽  
Author(s):  
Da Zhao ◽  
Peng Xu ◽  
Tobias Ritter
Keyword(s):  
Late Stage ◽  
Palladium Catalyzed

ChemInform Abstract: Generation of Diverse 2-Pyrones via Palladium-Catalyzed Site-Selective Suzuki-Miyaura Couplings of 3-Bromo-4-tosyloxy-2-pyrone.

ChemInform ◽  
2012 ◽  
Vol 43 (8) ◽  
pp. no-no
Author(s):  
Xiaoli Lei ◽  
Liang Gao ◽  
Qiuping Ding ◽  
Yiyuan Peng ◽  
Jie Wu
Keyword(s):  
Palladium Catalyzed ◽  
Site Selective
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