(2-Stannylated butadiene) tricarbonyl iron complexes: Practical reagents for the synthesis of 2-acyldienes

✍ Scribed by Pierre-Jean Colson; Michel Franck-Neumann; Madjid Sedrati

• Publisher: Elsevier Science
• Year: 1989
• Tongue: French
• Weight: 237 KB
• Volume: 30
• Category: Article
• ISSN: 0040-4039
• DOI: 10.1016/s0040-4039(01)80408-1

✦ Synopsis

A new route to the stable (2-acylbutadiene) tricarbonyl iron complexes is described, based on the palladium catalyzed coupling between acid chlorides and 2-stannylated butadiene complexes . Conjugated dienes bearing an electron-withdrawing group in position 2 are very reactive derivatives which are difficult to isolate as monomers, especially in the case of the parent a-substituted butadienes. These functionalized isoprenes form however stable tricarbonyl iron complexes (1). Unfortunately complexes of the type I with R = CHO or COR' are not accessible by electrophilic functionalization of (butadiene) tricarbonyl iron. This complex and complexes of simply alkylated butadienes are in fact readily acylated in the 1 or 4 position under Friedel-Crafts conditions (2). To our knowledge, access to 2-acyldienes via a Friedel-Crafts reaction of carbonyl iron complexes is limited to