Access to novel imidazo[1,5-a]pyrazine scaffolds by the combined use of a three-component reaction and a base-assisted intramolecular cyclization.
A novel and practical two-step approach to an intriguing class of imidazo[1,5-a]pyrazines with exocyclic C=X (X = CH2, O) bonds is described. The process utilizes a sequential three-component reaction of propargyl amine or aminoester, 1,2-diaza-1,3-dienes and isothiocyanates to furnish functionalized 2-thiohydantoins which are transformed into thiohydantoin-fused tetrahydropyrazines by subsequent regioselective base-promoted cyclization.
Department of Biomolecular Sciences, Section of Organic Chemistry and Organic Natural Compounds, University of Urbino "Carlo Bo", Via I Maggetti 24, 61029 Urbino, Italy. gianfranco.favi@uniurb.it.
Orazio A
OA
Attanasi
Gianfranco
G
Favi
Gianluca
G
Giorgi
Roberta
R
Majer
Francesca Romana
FR
Perrulli
Stefania
S
Santeusanio
D003500:Cyclization; D007093:Imidazoles / Q000138:chemical synthesis / Q000737:chemistry*; D008968:Molecular Conformation; D011719:Pyrazines / Q000138:chemical synthesis / Q000737:chemistry*; D013237:Stereoisomerism; D013867:Thiohydantoins / Q000737:chemistry
D007093:Imidazoles; D011719:Pyrazines; D013867:Thiohydantoins