1-(N-Acylamino)alkyltriarylphosphonium salts with weakened c α -P + bond strength⇔synthetic applications

Abstract

The α-amidoalkylating properties of 1-(N-acylamino)alkyltriarylphosphonium salts with weakened C α -P + bond strength are discussed and examined. It is demonstrated that such type of phosphonium salts reacts smoothly with a diverse array of carbon- and heteroatom-based nucleophiles, including 1-morpholinocyclohexene, 1,3-dicarbonyl compounds, benzotriazole sodium salt, p-toluenesulfinate sodium salt, benzylamine, triarylphosphines, and other P-nucleophiles. Reactions are conducted at room temperature, in a short time (5–15 min) and mostly without catalysts. Simple work-up procedures result in good or very good yields of products. The structures of known compounds were established by spectroscopic methods and all new compounds have been fully characterized using 1 H-, 13 C-, 31 P-NMR, IR spectroscopy, and high-resolution mass spectrometry. Mechanistic aspects of described transformations are also performed and discussed. It was demonstrated that unique properties make 1-(N-acylamino)alkyl-triarylphosphonium salts with weakened C α -P + bond strength interesting building blocks with great potential, especially in α-amidoalkylation reactions.