Methyl-N-(2,6-dimethylphenyl)-N-(methoxyacetyl)-DL-alaninat

BeschreibungAs an important fungicide group, acylanilides have a longer history than triazoles. Metalaxyl (44) is one of the most important fungicides in the group. It originates from the class of herbicidal chloroacetanilides, particularly metolachlor (45). Metolachlor, having a chiral carbon center and a chiral axis, is composed of four stereoisomers, the most herbicidally active one of which is the (αR, 1S)-isomer (32). For the stereoselective synthesis of this isomer, novel iridium-ferrocenyldiphosphine catalysts for the enantioselective hydrogenation of N-(2-ethyl-6-methylphenyl)- N-(1 -methoxymethyl)-ethylidene-amine are reported. In the most effective approach, the catalyst is generated in situ from [Ir(cod)Cl]2(cod = cyclooctadiene) and the ferrocenyldiphosphine ligand (R)-(S)-PPF-P(3,5-xyl)2 (46) (33).When the substrate to catalyst ratio is 106, the conversion is complete in 2 to 3 h, producing metolachlor in optical yields over 80% (34).

VerwendenMetalaxyl is used for the control of air-borne pathogens by foliar application and of soil-borne pathogens by soil application on a wide range of crops. It is particularly useful against Oomycetes including soil-borne Phytophthora diseases.