24361-06-6Relevant academic research and scientific papers
Assembly of 1,2,3,4-Tetrahydropyrrolo[1,2- a]pyrazines via the Domino Reaction of 2-Imidazolines and Terminal Electron-Deficient Alkynes
Festa, Alexey A.,Golantsov, Nikita E.,Golubenkova, Alexandra S.,Varlamov, Alexey V.,Voskressensky, Leonid G.
, (2022/02/05)
The transformation of 2-imidazolines into 1,2,3,4-tetrahydropyrrolo[1,2-a]pyrazines has been realized. A pseudo-three-component reaction of 2-imidazolines with terminal electron-deficient alkynes (2 equiv) first generates imidazolidines, containing an N-vinylpropargylamine fragment. The latter can then undergo a base-catalyzed domino aza-Claisen rearrangement/cyclization reaction sequence, simultaneously constructing pyrrole and pyrazine rings. The process works in a broad substrate scope, delivering pyrrolo[1,2-a]pyrazines in good to excellent yields (45-90%). This two-step approach can be carried out in a one-pot fashion without a noticeable decrease in yield. Remarkably, a three-component protocol for the introduction of two different alkynes has been also developed.
A Domino Route toward Polysubstituted Pyrroles from 2-Imidazolines and Electron-Deficient Alkynes
Festa, Alexey A.,Golantsov, Nikita E.,Golubenkova, Alexandra S.,Varlamov, Alexey V.,Voskressensky, Leonid G.
supporting information, (2020/06/29)
The reaction of 1,2-disubstituted 2-imidazolines with electron-deficient alkynes proceeds as a pseudo-three-component process and forms imidazolidines with an N-vinylpropargylamine fragment. Heating the resulting imidazolidines in xylene on air leads to a
Electrophilically activated nitroalkanes in reaction with aliphatic diamines en route to imidazolines
Aksenov, Alexander V.,Aksenov, Nicolai A.,Arutiunov, Nikolai A.,Malyuga, Vladimir V.,Ovcharov, Sergey N.,Rubin, Michael
, p. 39458 - 39465 (2019/12/14)
A novel synthetic methodology for the assembly of imidazolines via an unusual reaction between nitroalkanes and aliphatic 1,2-diamines in the presence of phosphorous acid is described. In contrast to the related highly efficient preparation of benzimidazoles from aromatic amines, this process represents a major synthetic challenge and for a long time was elusive. Analysis of the method limitations is provided.
Chemoselective Deprotection of Sulfonamides under Acidic Conditions: Scope, Sulfonyl Group Migration, and Synthetic Applications
Javorskis, Tomas,Orentas, Edvinas
, p. 13423 - 13439 (2017/12/26)
Chemoselective acidic hydrolysis of sulfonamides with trifluoromethanesulfonic acid has been evaluated as a deprotection method and further extended to more complex synthetic applications. In contrast to conventional troublesome sulfonamide hydrolysis, a near-stoichiometric amount of acid was found to be sufficient to bring about efficient deprotection of various neutral or electron-deficient N-arylsulfonamides, whereas electron-rich substrates provided sulfonyl group migration products. The deprotection method developed is fully selective for N-arylsulfonamides, and the possibility to discriminate among various different sulfonamides is demonstrated.
One-pot triflic anhydride-mediated synthesis of 1,2-disubstituted 2-imidazolines from N-(2-haloethyl)amides and amines
Ellsworth, Alyssa A.,Magyar, Christina L.,Hubbell, Grace E.,Theisen, Chelsea C.,Holmes, Daniel,Mosey, R. Adam
, p. 6380 - 6389 (2016/09/23)
A one-pot synthesis of 1,2-disubstituted 2-imidazolines from N-(2-haloethyl)amides has been developed. The reaction affords high yields of diverse 1,2-disubstituted 2-imidazolines from triflic anhydride-mediated dehydration of amides followed by installat
Copper-catalyzed N -arylation of 2-imidazolines with aryl iodides
Davis, Owen A.,Hughes, Matthew,Bull, James A.
supporting information, p. 3470 - 3475 (2013/06/26)
The first copper-catalyzed N-arylation of 2-imidazolines is described. The reaction affords compounds with desirable lead-like characteristics in high yield with practical simplicity under inexpensive, ligand-free conditions. The cross coupling was successful with electron-rich and electron-poor aromatic iodides. Substrates bearing halides, esters, nitriles, and free hydroxyls are well tolerated, providing reactive handles for further functionalization, as are pyridines. In addition, the regioselective N-arylation of a 4-substituted imidazoline is reported.
New cycloplatinated complexes with 2-arylimidazolines: Synthesis, crystal structures and photophysical properties
Gong, Jun-Fang,Fan, Xin-Heng,Xu, Chen,Li, Jin-Lei,Wu, Yang-Jie,Song, Mao-Ping
, p. 2006 - 2013 (2007/10/03)
The synthesis, crystal structures and photophysical properties of a series of cycloplatinated complexes are presented. The complexes have the general formula (C∧N)Pt(O∧O), where O∧O is acetylacetonate and C∧N re
Nucleophilic Addition to Substituted 1H-4,5-Dihydroimidazolium Salts
Salerno, Alejandra,Ceriani, Vanina,Perillo, Isabel A.
, p. 709 - 716 (2007/10/03)
1H-4,5-Dihydroimidazolium salts 1 react readily with nucleophilic reagents originating cyclic products which may be stable or become transformed into acyclic compounds maintaining the structural ethylenediamine unit. With methylmagnesium iodide compound le affords the expected imidazolidine, but in the case of substituted 1-aryl-3-methyl-2-phenyl salts 1b-d the N-aryl-N'-methylethylenediamines 3b-d and acetophenone (4) were isolated, the process representing the transfer of the C-2 unit to a nucleophilic carbon. With alkaline cyanides salts 1 react efficiently affording α,α-diaminonitriles 5. In these compounds the cyano group may be readily substituted by nucleophiles (hydroxyl anion, species with nucleophilic carbon and reagents that act by hydride ion transfer), in a way similar to the salts but with better yields.
