Abstract
Phenyl, tolyl, anisyl, and 1-naphthyl iodides (7a-g, n) smoothly reacted with (S)-N-(benzyloxycarbonyl)-vinylglycine (6) in H2O in the presence of Pd(OAc)2, Bu4NCl, and NaHCO3 at 45°C, producing [S-(E)]-(2-arylvinyl)glycine derivatives 8a-g, n of high enantiomeric purity. The yields of the reactions of 3- (7f), 2- (7e), and 4-iodoanisoles (7g) increased in this order. This relationship between the yield and the position of substitution has been found to hold for bromophenyl iodides (7i-k), although somewhat lower chemical and optical yields were realized in these cases. Phenyl iodide 7l carrying an electron-withdrawing 4-acetyl group gave an unsatisfactory result, and more electron-deficient 4-nitrophenyl iodide (7m) did not provide the desired product. All these results suggest that the reaction is advantageous with electron-sufficient substrates 7. However, this was not the case for 4-iodophenol (7h), as well as some heterocyclic iodides.
