Iron-catalyzed 1,6-addition of aryl Grignard reagents to 2,4-dienoates and -dienamides

1,6-Addition of aryl Grignard reagents to 2,4-dienoates or -dienamides was nicely catalyzed by iron salt to give 5-aryl-3-enoates or the corresponding amides in a highly regio- and stereoselective manner.