Titanium isopropoxide as efficient catalyst for the aza-Baylis-Hillman reaction. Selective formation of alpha-methylene-beta-amino acid derivatives.
The direct formation of alpha-methylene-beta-amino acid derivatives is achieved using the aza version of the Baylis-Hillman protocol. The products are readily formed in a three-component one-pot reaction between arylaldehydes, sulfonamides, and alpha,beta-unsaturated carbonyl compounds. The reaction is efficiently catalyzed by titanium isopropoxide and 2-hydroxyquinuclidine in the presence of molecular sieves. The protocol allows for structural variation of the substrates, tolerating electron-poor and electron-rich arylaldehydes and various Michael acceptors.
Balan
Daniela
D
Department of Organic Chemistry, Stockholm University, SE-106 91 Stockholm, Sweden.
Adolfsson
Hans
H
D000596:Amino Acids / Q000138:chemical synthesis* / Q000737:chemistry; D002384:Catalysis; D002625:Chemistry, Organic / Q000379:methods; D015394:Molecular Structure; D010666:Phenylpropionates / Q000138:chemical synthesis* / Q000737:chemistry; D014025:Titanium / Q000737:chemistry*; D014105:Tosyl Compounds / Q000138:chemical synthesis* / Q000737:chemistry
D000596:Amino Acids; D010666:Phenylpropionates; D014105:Tosyl Compounds; C459663:methylmethylene-((p-toluenesulfonyl)amino)-3-phenylpropionate; D014025:Titanium