Transition-metal free C(sp2)–C(sp2) bond formation: arylation of 4-aminocoumarins using arynes as an aryl source

2019 ◽  
Vol 17 (40) ◽  
pp. 9014-9025 ◽  
Author(s):  
Abhilash Sharma ◽  
Pranjal Gogoi

A mild, efficient and transition-metal free synthetic strategy has been developed for the α-arylation of 4-aminocoumarins using arynes as an aryl source. This synthetic strategy proceeds via C(sp2)–C(sp2) bond formation between 4-aminocoumarins and aryne precursors in a single step in the absence of a metal-catalyst.

2020 ◽  
Vol 44 (41) ◽  
pp. 17938-17953
Author(s):  
Abhilash Sharma ◽  
Pranjal Gogoi

A versatile transition-metal free synthetic strategy has been developed for the direct synthesis of 6-substituted indoloquinazolinones from 2-acyl-4-quinazolinones and aryne precursors. This cascade strategy proceeds via successive C–N and C–C bond formation in a single reaction vessel.


2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Guogang Deng ◽  
Shengzu Duan ◽  
Jing Wang ◽  
Zhuo Chen ◽  
Tongqi Liu ◽  
...  

AbstractAllylation of nucleophiles with highly reactive electrophiles like allyl halides can be conducted without metal catalysts. Less reactive electrophiles, such as allyl esters and carbonates, usually require a transition metal catalyst to facilitate the allylation. Herein, we report a unique transition-metal-free allylation strategy with allyl ether electrophiles. Reaction of a host of allyl ethers with 2-azaallyl anions delivers valuable homoallylic amine derivatives (up to 92%), which are significant in the pharmaceutical industry. Interestingly, no deprotonative isomerization or cyclization of the products were observed. The potential synthetic utility and ease of operation is demonstrated by a gram scale telescoped preparation of a homoallylic amine. In addition, mechanistic studies provide insight into these C(sp3)–C(sp3) bond-forming reactions.


2017 ◽  
Vol 2 (17) ◽  
pp. 4963-4968 ◽  
Author(s):  
Abhinandan D. Hudwekar ◽  
G. Lakshma Reddy ◽  
Praveen K. Verma ◽  
Sorav Gupta ◽  
Ram A. Vishwakarma ◽  
...  

2020 ◽  
Vol 56 (88) ◽  
pp. 13607-13610 ◽  
Author(s):  
Rajagopal Pothikumar ◽  
Venugopal T Bhat ◽  
Kayambu Namitharan

Herein, we report aza-aromatics based organic mediators as a readily accessible alternative to the traditional approach of using transition metal catalyst systems for the activation of alcohols in borrowing hydrogen reactions.


Synlett ◽  
2018 ◽  
Vol 29 (05) ◽  
pp. 548-555 ◽  
Author(s):  
Liang-Nian He ◽  
Xiao-Fang Liu ◽  
Xiao-Ya Li ◽  
Chang Qiao

Reductive functionalization of CO2 with amines and a reductant, which combines both reduction of CO2 and C–N bond formation in one pot to produce versatile chemicals and energy-storage materials such as formamides, aminals, and methylamines that are usually derived from petroleum feedstock, would be appealing and promising. Herein, we give a brief review on recent developments in the titled CO2 chemistry by employing transition-metal-free catalysis, which can be catalogued as below according to the diversified energy content of the products, that is formamides, aminals, and methylamines being consistent with 2-, 4-, and 6-electron reduction of CO2, respectively. Notably, hierarchical reduction of CO2 with amines to afford at least two products, for example, formamides and methylamines, could be realized with the same catalyst through tuning the hydrosilane type, reaction temperature, or CO2 pressure. Finally, the opportunities and challenges of the reductive functionalization of CO2 with amines are also highlighted.1 Introduction2 2-Electron Reduction of CO2 to Formamide3 6-Electron Reduction of CO2 to Methylamine4 4-Electron Reduction of CO2 to Aminal5 Hierarchical Reduction of CO2 with Amines6 Conclusion


Sign in / Sign up

Export Citation Format

Share Document