New efficient procedures for direct introduction of the agrochemically important beta-methoxypropenoate unit into substituted aromatic derivatives

Two simple and efficient procedures for the synthesis of methyl (E)-2-aryl-3-methoxypropenoates 1 were developed. The first procedure involves a Pd-catalyzed cross-coupling reaction between arylzinc chlorides and methyl (Z)-2-iodo-3-methoxypropenoate 4. The second procedure consists in a Pd-catalyzed cross-coupling reaction between arylboronic acids and methyl (Z)-2-bromo-3-methoxypropenoate 6. This electrophile has been prepared by Pd-catalyzed reaction of methyl (Z)-2,3-dibromopropenoate 7 with Bu(3)SnOMe. Other unprecedented regioselective carbon-oxygen bond and carbon-sulfur bond forming reactions occurred when 7 or its stereoisomer was reacted with alkoxy- and arylthio- or alkylthio-tributylstannanes,respectively, in the presence of Pd(PPh(3))(4).