Construction of linked nitrogen heterocycles by palladium(0)-catalyzed intramolecular domino cyclization of 2-alkynylaziridines bearing a 2-aminoethyl group via ring expansion with isocyanate.
A novel palladium(0)-catalyzed domino cyclization of 2-alkynylaziridines with isocyanates through ring expansion is described. Treatment of N-protected 2-(4-aminobut-1-ynyl)aziridine derivatives with a catalytic amount of Pd(PPh(3))(4) and aryl isocyanates in THF at room temperature affords 4-(4,5-dihydropyrrol-2-yl)imidazolidin-2-one derivatives in good yields. Interestingly, bis-adducts were selectively obtained by use of excess isocyanate (5 equiv) at lower reaction temperature.
Okano
Akinori
A
Graduate School of Pharmaceutical Sciences, Kyoto University, Sakyo-ku, Kyoto 606-8501, Japan.
Oishi
Shinya
S
Tanaka
Tetsuaki
T
Fujii
Nobutaka
N
Ohno
Hiroaki
H
D001388:Aziridines / Q000138:chemical synthesis* / Q000737:chemistry*; D002384:Catalysis; D003500:Cyclization; D006571:Heterocyclic Compounds / Q000737:chemistry*; D017953:Isocyanates / Q000737:chemistry*; D015394:Molecular Structure; D009942:Organometallic Compounds / Q000737:chemistry*; D010165:Palladium / Q000737:chemistry*; D013237:Stereoisomerism
D001388:Aziridines; D006571:Heterocyclic Compounds; D017953:Isocyanates; D009942:Organometallic Compounds; D010165:Palladium