TITLE:
Three-Component Coupling Catalyzed by Phosphine: Preparation of α-Amino γ-Oxo Acid Derivatives
AUTHORS:
Yohei Oe, Takeshi Inoue, Hiroaki Kishimoto, Mitsuhiro Sasaki, Tetsuo Ohta, Isao Furukawa
KEYWORDS:
Three-Component Coupling; Phosphine; 2-Amino-4-Oxocarboxylic Acid
JOURNAL NAME:
International Journal of Organic Chemistry,
Vol.2 No.2,
June
27,
2012
ABSTRACT: The three-component coupling reaction of ethyl propiolate (1), phthalimide (2), and aldehyde (3) catalyzed by tripheny- lphosphine, was developed. A solution of an equivalent amount of 1 and 2 in benzaldehyde (3a) in the presence of 30 mol% of PPh3 was heated at 100?C for 48 h to give N-(1-ethoxycarbonyl-3-oxo-3-phenylpropyl)phthalimide (4a) in 83% yield. This reaction was thought to proceed via vinylphosphonium salt formed from the reaction of ethyl propiolate (1) with triphenylphosphine in situ.