Flexible protocol for the chemo- and regioselective building of pyrroles and pyrazoles by reactions of Danishefsky's dienes with 1,2-diaza-1,3-butadienes.
The versatility of the Mukaiyama-Michael-type addition/heterocyclization of Danishefsky's diene with 1,2-diaza-1,3-butadienes was applied to the synthesis of both 4 H-1-aminopyrroles and 4,5 H-pyrazoles. Thus, the same reagents furnished different types of highly functionalized azaheterocycles essentially depending on their structure: as a matter of fact, R1 = COOR or CONR 2 differently affects the acidity of the proton at the adjacent carbon. An unexpected formation of 5 H-1-aminopyrroles from the reactions carried out in water was also observed.
Attanasi
Orazio A
OA
Istituto di Chimica Organica, Università degli Studi di Urbino Carlo Bo, Via I Maggetti 24, 61029 Urbino, Italy.
Favi
Gianfranco
G
Filippone
Paolino
P
Giorgi
Gianluca
G
Mantellini
Fabio
F
Moscatelli
Giada
G
Spinelli
Domenico
D
D000466:Alkadienes / Q000737:chemistry*; D001372:Aza Compounds / Q000737:chemistry*; D002070:Butadienes / Q000737:chemistry*; D003500:Cyclization; D015394:Molecular Structure; D011720:Pyrazoles / Q000138:chemical synthesis* / Q000737:chemistry; D011758:Pyrroles / Q000138:chemical synthesis* / Q000737:chemistry; D013237:Stereoisomerism
D000466:Alkadienes; D001372:Aza Compounds; D002070:Butadienes; D011720:Pyrazoles; D011758:Pyrroles