In situ generation and protonation of the isocyanide/acetylene adduct: a powerful catalyst-free strategy for multicomponent synthesis of ketenimines, aza-dienes, and heterocycles

RSC Advances ◽  
2015 ◽  
Vol 5 (117) ◽  
pp. 97044-97065 ◽  
Author(s):  
Sadegh Rostamnia

In addition to isocyanide-based Ugi, Passerini, van Leusen, and Orru multicomponent reactions, a new class of isocyanide/acetylene-based multicomponent reactions, using zwitterionic adducts, have emerged as powerful methods to synthesize biologically interesting molecules.

2011 ◽  
Vol 6 (1) ◽  
pp. 1934578X1100600 ◽  
Author(s):  
Hamdoon A. Mohammed ◽  
Lalla A. Ba ◽  
Torsten Burkholz ◽  
Elena Schumann ◽  
Britta Diesel ◽  
...  

Flavones such as chrysin show structural similarities to androgens, the substrates of human aromatase, which converts androgens to estrogens. Aromatase is a key target in the treatment of hormone-dependent tumors, including breast cancer. Flavone-based aromatase inhibitors are of growing interest, and chrysin in particular provides a (natural) lead structure. This paper reports multicomponent synthesis as a means for facile modification of the chrysin core structure in order to add functional elements. A Mannich-type reaction was used to synthesize a range of mono- and disubstituted chrysin derivatives, some of which are more effective aromatase inhibitors than the benchmark compound, aminoglutethimide. Similarly, the reaction of chrysin with various isonitriles and acetylene dicarboxylates results in a new class of flavone derivatives, tricyclic pyrano-flavones which also inhibit human aromatase. Multicomponent reactions involving flavones therefore enable the synthesis of a variety of derivatives, some of which may be useful as anticancer agents.


2019 ◽  
Vol 8 (1) ◽  
pp. 42-52 ◽  
Author(s):  
Chahrazed Benhaoua ◽  
Mustapha Rahmouni ◽  
Hadj Benhaoua

The microwave-promoted one-pot multicomponent synthesis of substituted pyrrolidinols using a bifunctional sugar-derived hydroxy-[gamma]-lactone component of amine component or cyanide group is reported. Clean reaction profile, easy work-up procedure, excellent yields and short reaction times are some remarkable features of this method.This modular approach features the in situ-generation of iminium ions intermediate that allows the diastereoselective assembly of the diverse pyrrolidinones efficiently under microwave irradiation has been used.


2019 ◽  
Vol 15 ◽  
pp. 497-505 ◽  
Author(s):  
Grzegorz Mlostoń ◽  
Małgorzata Celeda ◽  
Katarzyna Urbaniak ◽  
Marcin Jasiński ◽  
Vladyslav Bakhonsky ◽  
...  

Adamantyloxyamine reacts with formaldehyde to give N-(adamantyloxy)formaldimine as a room-temperature-stable compound that exists in solution in monomeric form. This product was used for reactions with α-hydroxyiminoketones leading to a new class of 2-unsubstituted imidazole 3-oxides bearing the adamantyloxy substituent at N(1). Their reactions with 2,2,4,4-tetramethylcyclobutane-1,3-dithione or with acetic acid anhydride occurred analogously to those of 1-alkylimidazole 3-oxides to give imidazol-2-thiones and imidazol-2-ones, respectively. Treatment of 1-(adamantyloxy)imidazole 3-oxides with Raney-Ni afforded the corresponding imidazole derivatives without cleavage of the N(1)–O bond. Finally, the O-alkylation reactions of the new imidazole N-oxides with 1-bromopentane or 1-bromododecane open access to diversely substituted, non-symmetric 1,3-dialkoxyimidazolium salts. Adamantyloxyamine reacts with glyoxal and formaldehyde in the presence of hydrobromic acid yielding symmetric 1,3-di(adamantyloxy)-1H-imidazolium bromide in good yield. Deprotonation of the latter with triethylamine in the presence of elemental sulfur allows the in situ generation of the corresponding imidazol-2-ylidene, which traps elemental sulfur yielding a 1,3-dihydro-2H-imidazole-2-thione as the final product.


Author(s):  
Kazumasa Funabiki ◽  
Toshiya Gotoh ◽  
Ryunosuke Kani ◽  
Toshiyasu Inuzuka ◽  
Yasuhiro Kubota

A highly diastereo- and enantioselective organocatalytic method to synthesise erythritols bearing a trifluoromethyl group has been investigated.


2020 ◽  
Vol 24 ◽  
Author(s):  
Wengui Wang ◽  
Shoufeng Wang

Abstract:: Minisci-type reactions have become widely known as reactions that involve the addition of carbon-centered radicals to basic heteroarenes followed by formal hydrogen atom loss. While the originally developed protocols for radical generation remain in active use today, in recent years by a new array of radical generation strategies allow use of a wider variety of radical precursors that often operate under milder and more benign conditions. New transformations based on free radical reactivity are now available to a synthetic chemist looking to utilize a Minisci-type reaction. Radical-generation methods based on photoredox catalysis and electrochemistry, which utilize thermal cleavage or the in situ generation of reactive radical precursors, have become popular approaches. Our review will cover the remarkably literature that has appeared on this topic in recent 5 years, from 2015-01 to 2020-01, in an attempt to provide guidance to the synthetic chemist, on both the challenges that have been overcome and applications in organic synthesis.


2013 ◽  
Vol 16 (10) ◽  
pp. 788-790
Author(s):  
Zinatossadat Hossaini ◽  
Samereh Seyfi ◽  
Faramarz Rostami-Charati ◽  
Mehdi Ghambarian

2021 ◽  
Author(s):  
Thomas Richards ◽  
Jonathan H. Harrhy ◽  
Richard J. Lewis ◽  
Alexander G. R. Howe ◽  
Grzegorz M. Suldecki ◽  
...  

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