Potassium tris(triflyl)methide (KCTf3): a broadly applicable promoter for cationic metal catalysis

2015 ◽  
Vol 51 (72) ◽  
pp. 13740-13743 ◽  
Author(s):  
Junbin Han ◽  
Zhichao Lu ◽  
Weibo Wang ◽  
Gerald B. Hammond ◽  
Bo Xu

KCTf3 enhanced the reaction rates and the chemical yields of a wide spectrum of cationic metal catalyzed reactions in consistent and significant manner. These reactions include traditional Lewis acid catalysis and transition metal catalysis. KCTf3 is an easily handled neutral salt that is commercially available.

2015 ◽  
Vol 51 (2) ◽  
pp. 254-265 ◽  
Author(s):  
Wen-Xiong Zhang ◽  
Ling Xu ◽  
Zhenfeng Xi

This article provides an overview of guanidine synthesis via transition-metal-catalyzed reactions including cycloaddition, guanylation and tandem guanylation/cyclization.


Synthesis ◽  
2020 ◽  
Vol 52 (06) ◽  
pp. 819-833 ◽  
Author(s):  
Jen-Chieh Hsieh ◽  
Haw-Lih Su

The diverse methodologies to synthesize N-heterocycles through transition-metal-catalyzed cascade addition/cyclization of a nitrile are discussed in this review. Aspects relating to three types of transition-metal-catalyzed addition of a nitrile with subsequent cyclization include (1) a transition-metal acting as a Lewis acid to accelerate the nucleophilic addition of a nitrile, (2) the late-transition-metal-catalyzed 1,2-insertion of a nitrile, and (3) an in situ generated radical by transition-metal catalysis to implement a radical addition/cyclization tandem reaction. Applications for the synthesis of natural alkaloids, their derivatives, and some bioactive compounds are also summarized herein.1 Introduction2 Nucleophilic Addition of a Nitrile Accelerated by a Lewis Acid2.1 Late-Transition-Metal Catalysis2.2 Early-Transition-Metal Catalysis2.3 Lanthanide-Metal Catalysis2.4 Cyclization from N-Arylnitriliums3 Transition-Metal-Catalyzed Insertion of a Nitrile4 Transition-Metal-Catalyzed Radical Addition of a Nitrile5 Conclusions


2020 ◽  
Vol 49 (7) ◽  
pp. 2039-2059 ◽  
Author(s):  
Daniel G. Rivera ◽  
Gerardo M. Ojeda-Carralero ◽  
Leslie Reguera ◽  
Erik V. Van der Eycken

Peptide macrocyclization continues expanding with the development of novel transition metal-catalyzed reactions capable of both introducing conformational constraints and generating diversity at the ring-closing moiety.


2021 ◽  
Vol 19 (37) ◽  
pp. 7949-7969
Author(s):  
Prasanjit Ghosh ◽  
Sajal Das

Indole and its congeners are ubiquitous nitrogen containing organic scaffolds found in a plethora of natural products. This review aims to highlight the transition-metal catalyzed C–H functionalization of N-alkoxycarbamoyl indoles.


Molecules ◽  
2020 ◽  
Vol 25 (21) ◽  
pp. 4970
Author(s):  
Su Chen ◽  
Prabhat Ranjan ◽  
Leonid G. Voskressensky ◽  
Erik V. Van der Eycken ◽  
Upendra K. Sharma

The transition metal-catalyzed C–H bond functionalization of azoles has emerged as one of the most important strategies to decorate these biologically important scaffolds. Despite significant progress in the C–H functionalization of various heteroarenes, the regioselective alkylation and alkenylation of azoles are still arduous transformations in many cases. This review covers recent advances in the direct C–H alkenylation, alkylation and alkynylation of azoles utilizing transition metal-catalysis. Moreover, the limitations of different strategies, chemoselectivity and regioselectivity issues will be discussed in this review.


Author(s):  
Han Gao ◽  
Lingfei Hu ◽  
Yanlei Hu ◽  
Xiangying Lv ◽  
Yanbo Wu ◽  
...  

The current understanding of Lewis acid effects in transition metal catalysis is generally based on the enhanced charge transfer from metal to substrate due to the formation of Lewis acid-base...


2014 ◽  
Vol 5 (6) ◽  
pp. 2146-2159 ◽  
Author(s):  
Xi-Sha Zhang ◽  
Kang Chen ◽  
Zhang-Jie Shi

Compared with the traditional Grignard reaction, direct insertion of polar double bonds to C–H bonds via transition-metal catalysis is ideal from the viewpoint of atom-, step- and cost-economy and the avoidance of the waste emission, as well as of the complex manipulation of sensitive reagents.


2019 ◽  
Author(s):  
Keri Steiniger ◽  
Tristan Lambert

The efficient and regioselective hydrosilylation of epoxides co-catalyzed by a pentacarboxycyclopentadienyl (PCCP) diamide nickel complex and Lewis acid is reported. This method allows for the reductive opening of terminal, monosubstituted epoxides to form unbranched, primary alcohols. A screen of diamide PCCP ligands revealed a correlation of steric demand and regioselectivity, with smaller ligands being optimal, while the addition of Lewis acid enabled efficient reactions at room temperature. A range of substrates including both terminal and non-terminal epoxides are shown to work, and a mechanistic rationale is provided. This work represents the first use of a PCCP derivative as a ligand for transition metal catalysis.


Synthesis ◽  
2021 ◽  
Author(s):  
Jie Jia ◽  
Fangdong Hu ◽  
Ying Xia

Transition-metal-catalyzed nucleophilic dearomatization of electron-deficient heteroarenes, such as pyridines, quinolines, isoquinolines and nitroindoles, has become a powerful method for the access of unsaturated heterocycles in recent decades. This short review summarizes nucleophilic dearomatization of electron-deficient heteroarenes with carbon- and heteroatom-based nucleophiles via transition-metal catalysis. A great number of functionalized heterocycles were obtained in this transformation. Importantly, many of these reactions were carried out in an enantioselective manner by means of asymmetric catalysis, providing a unique method for the construction of enantioenriched heterocycles. 1 Introduction 2 Transition-metal-catalyzed nucleophilic dearomatization of heteroarenes via alkynylation 3 Transition-metal-catalyzed nucleophilic dearomatization of heteroarenes via arylation 4 Transition-metal-catalyzed nucleophilic dearomatization of heteroarenes with other nucleophiles 5 Transition-metal-catalyzed nucleophilic dearomatization with nucleophiles formed in situ 6 Conclusion and outlook


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