Catalyst-free 1,6-conjugate addition of indoles and 4-hydroxycoumarins to para-quinone methides: synthesis of unsymmetrical triarylmethanes

2020 ◽  
Vol 18 (39) ◽  
pp. 7837-7841
Author(s):  
Subramani Kumaran ◽  
Mohan Prabhakaran ◽  
Narayanan Mariyammal ◽  
Kanniyappan Parthasarathy
Keyword(s):  
Michael Reaction ◽  
Conjugate Addition ◽  
Quinone Methides ◽  
Metal Free ◽  
Catalyst Free

We have successfully developed an efficient metal-free 1,6-Michael reaction of indoles and 4-hydroxycoumarins with para-quinone methides to afford heterocyclic triarylmethanes in good yields.

scholarly journals Catalyst-Free 1,6-Conjugate Addition/Aromatization/Sulfonylation of para-Quinone Methides: Facile Access to Diarylmethyl Sulfones

ACS Omega ◽  
2018 ◽  
Vol 3 (2) ◽  
pp. 1409-1415 ◽  
Author(s):  
Teng Liu ◽  
Jianjun Liu ◽  
Shubiao Xia ◽  
Jie Meng ◽  
Xianfu Shen ◽  
...  
Keyword(s):  
Conjugate Addition ◽  
Quinone Methides ◽  
Catalyst Free

Metal-free synthesis of triarylated (Z)-nitrones via H2O-mediated 1,3-dipolar transfer under aerobic conditions

2019 ◽  
Vol 21 (3) ◽  
pp. 675-683 ◽  
Author(s):  
Ke Chen ◽  
Wen-Juan Hao ◽  
Shu-Jiang Tu ◽  
Bo Jiang
Keyword(s):  
Good Yield ◽  
Transfer Reaction ◽  
Environmentally Benign ◽  
Quinone Methides ◽  
Aerobic Conditions ◽  
Metal Free ◽  
Catalyst Free

A new and environmentally benign protocol aimed at the generation of triarylated (Z)-nitrones in generally good yield has been developed via metal- and catalyst-free H2O-mediated 1,3-dipolar transfer reaction of para-quinone methides (p-QMs) with diarylated nitrones under aerobic conditions.

Metal-free, Tf2NH-catalyzed 1, 6-conjugate addition of imidazopyridine to para-quinone methides: Easy access to C3-functionalized triarylmethane imidazopyridine

Tetrahedron ◽  
2021 ◽  
pp. 132510
Author(s):  
Nilesh S. Khonde ◽  
Madhukar S. Said ◽  
Jagjivan K. Sabane ◽  
Jayant M. Gajbhiye ◽  
Pradeep Kumar
Keyword(s):  
Conjugate Addition ◽  
Easy Access ◽  
Quinone Methides ◽  
Metal Free

Metal-Free Photoinduced Hydroalkylation Cascade Enabled by an Electron-Donor-Acceptor Complex

2020 ◽  
Author(s):  
José Tiago Menezes Correia ◽  
Gustavo Piva da Silva ◽  
Camila Menezes Kisukuri ◽  
Elias André ◽  
Bruno Pires ◽  
...  
Keyword(s):  
Electron Donor ◽  
Functional Group ◽  
Photoexcited Electron ◽  
One Pot ◽  
Quaternary Centers ◽  
Metal Free ◽  
Acceptor Complex ◽  
Catalyst Free ◽  
Donor Acceptor ◽  
Radical Cascade

A metal- and catalyst-free photoinduced radical cascade hydroalkylation of 1,7-enynes has been disclosed. The process is triggered by a SET event involving a photoexcited electron-donor-aceptor complex between NHPI ester and Hantzsch ester, which decomposes to afford a tertiary radical that is readily trapped by the enyne. <a>The method provides an operationally simple, robust and step-economical approach to the construction of diversely functionalized dihydroquinolinones bearing quaternary-centers. A sequential one-pot hydroalkylation-isomerization approach is also allowed giving access to a family of quinolinones. A wide substrate scope and high functional group tolerance was observed in both approaches</a>.

Catalyst-free synthesis of phenanthridines via electrochemical coupling of 2-isocyanobiphenyls and amines

2021 ◽  
Vol 45 (14) ◽  
pp. 6367-6378
Author(s):  
Bhanwar Kumar Malviya ◽  
Karandeep Singh ◽  
Pradeep K. Jaiswal ◽  
Manvika Karnatak ◽  
Ved Prakash Verma ◽  
...  
Keyword(s):  
One Pot ◽  
Metal Free ◽  
Catalyst Free ◽  
Electrochemical Coupling

One pot metal-free synthesis of phenanthridines and amides under electrochemical conditions.

scholarly journals Metal-Free Catalysts for the Polymerization of Alkynyl-Based Monomers

Catalysts ◽  
2020 ◽  
Vol 11 (1) ◽  
pp. 1 ◽  
Author(s):  
Jie Zhang ◽  
Zhiming Zhang ◽  
Fulin Yang ◽  
Haoke Zhang ◽  
Jingzhi Sun ◽  
...  
Keyword(s):  
Lewis Acid ◽  
Research Focus ◽  
Catalytic Systems ◽  
Metal Free ◽  
Catalyst Free ◽  
Material Sciences ◽  
Acid Catalyzed

Novel polymerizations based on alkyne monomers are becoming a powerful tool to construct polymers with unique structures and advanced functions in the areas of polymer and material sciences, and scientists have been attracted to develop a variety of novel polymerizations in recent decades. Therein, catalytic systems play an indispensable role in the influence of polymerization efficiencies and the performances of the resultant polymers. Concerning the shortcomings of metallic catalysts, much of the recent research focus has been on metal-free polymerization systems. In this paper, metal-free catalysts are classified and the corresponding polymerizations are reviewed, including organobase-catalyzed polymerizations, Lewis-acid-catalyzed polymerizations, as well as catalyst-free polymerizations. Moreover, the challenges and perspectives in this area are also briefly discussed.

Copper-catalyzed 1,6-conjugate addition of para-quinone methides with diborylmethane

2021 ◽  
Author(s):  
Xin Li ◽  
Guoliang Gao ◽  
Songtao He ◽  
Qiuling Song
Keyword(s):  
Catalytic System ◽  
Conjugate Addition ◽  
Quinone Methides ◽  
High Yields

Presented herein is the first 1,6-conjugate addition of diborylmethane, which is promoted by a simple and inexpensive copper catalytic system. This method features high yields, good selectivities and broad functional...

Organocatalytic cascade 1,6-conjugate addition/annulation/tautomerization of functionalized para-quinone methides: Access to chiral 2-amino-4-aryl-4H-chromenes

2018 ◽  
Vol 29 (8) ◽  
pp. 1273-1276 ◽  
Author(s):  
Cong Duan ◽  
Ling Ye ◽  
Wenqin Xu ◽  
Xinying Li ◽  
Feng Chen ◽  
...  
Keyword(s):  
Conjugate Addition ◽  
Quinone Methides

scholarly journals Photoredox radical conjugate addition of dithiane-2-carboxylate promoted by an iridium(iii) phenyl-tetrazole complex: a formal radical methylation of Michael acceptors

2017 ◽  
Vol 8 (2) ◽  
pp. 1613-1620 ◽  
Author(s):  
Andrea Gualandi ◽  
Elia Matteucci ◽  
Filippo Monti ◽  
Andrea Baschieri ◽  
Nicola Armaroli ◽  
...  
Keyword(s):  
Michael Reaction ◽  
Conjugate Addition ◽  
Michael Acceptors

An iridium(iii) phenyl-tetrazole complex is a versatile catalyst for a new photocatalytic Michael reaction.

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