Practical and Efficient Synthesis of (E)-α,β-Unsaturated Amides Bearing (S)-α-Methylbenzylamine from 2-Phosphonamides via Horner-Wadsworth-Emmons Reaction

Abstract

E ) -a , b -U n s a t u r a t e d A m i d e s B e a r i n g ( S ) -a -M e t h y l b e n z y l a m i n e Abstract: The highly stereoselective synthesis of (E)-a,b-unsaturated amides bearing (S)-a-methylbenzylamine was achieved from 2-phosphonamides via Horner-Wadsworth-Emmons reaction. The starting phosphonamides are easily prepared in two steps with excellent yields via the standard Arbuzov reaction of trimethylphosphite and a-bromoamides.

Green synthesis of ethyl cinnamates under microwave irradiation: photophysical properties, cytotoxicity, and cell bioimaging

“…Cinnamates 3a-f were prepared in an easy way applying the widely known HWE reaction [45][46][47] using triethyl phosphonoacetate 1 as the starting material, and commercially available aryl aldehydes 2a-f [4-(diethylamino)benzaldehyde, 4-(diphenylamino)benzaldehyde, terephthaldehyde, 4-(4-morpholinyl)benzaldehyde, 4-acetamidobenzaldehyde, and 3,4,5trimethoxybenzaldehyde] using K 2 CO 3 as base and ethanol as solvent, under microwave irradiation at 140 °C for 20 min. Aer purication either by chromatography column or crystallization, the compounds 3a-f were obtained predominantly as E isomers with 73% to 96% yields (Scheme 1).…”