Graphene oxide as a catalyst for one-pot sequential aldol coupling/aza-Michael addition of amines to chalcones through in situ generation of Michael acceptors under neat conditions

• Published in: Tetrahedron letters Vol. 61; no. 6; pp. 151470 - 151475
• Main Authors: Khalili, Dariush, Lavian, Salime, Moayyed, Mohammadesmaeil
• Format: Journal Article
• Language: English
• Published: OXFORD Elsevier Ltd 06.02.2020; Elsevier
• Subjects: Aza-Michael addition; Chalcones; Chemistry; Chemistry, Organic; Graphene oxide; Physical Sciences; Science & Technology; Solvent-free; Aza-Michael addition; Chalcones; Graphene oxide; Solvent-free; OXIDATION; KETONES; HETEROCYCLES; REDUCTION; CARBOCATALYST; AROMATIC-AMINES
• ISSN: 0040-4039; 1873-3581
• DOI: 10.1016/j.tetlet.2019.151470

[Display omitted] •GO catalyzed sequential aldol coupling/aza-Michael addition of aromatic amines to chalcones.•In situ generation of chalcones under solvent and metal-free conditions.•Using of aromatic amines as weak nucleophiles in aza-Michael addition.•Having easy and rapid recycling protocol for catalyst by filtration.•Synthesis of β-amino ketones in high yields. Graphene oxide (GO) in conjunction with tetra n-butyl ammonium bromide (TBAB) was found to function as an efficient catalyst for one-pot sequential aldol coupling/aza-Michael addition of amines to chalcones in a single reaction vessel. Benzaldehydes and acetophenone were coupled in situ to produce their corresponding chalcones which underwent a subsequent aza-Michael addition under solvent-free condition. This procedure avoids the use of precious metals and the heterogeneous nature of the GO simplifies purification and isolation of the products by simple filtration of the catalyst.