REGIO- AND STEREOCONTROLLED FUNCTIONALIZATION OF CYCLOHEPTADIENE USING ORGANOIRON AND ORGANOSELENIUM CHEMISTRY.

Article abstract of DOI:10.1021/ja00332a050

Whereas the reactions of tricarbonylcycloheptadienyliron salts with nucleophiles generally occur in low yield giving mixtures of products, the corresponding dicarbonyl(triphenylphosphine) and dicarbonyl(triphenyl phosphite) complexes 8 give high yields of single adducts on reaction with a range of nucleophiles. The regioselectivity of nucleophile addition to 8 is strongly dependent on the nucleophile, 'soft' nucleophiles attacking C-1, 'hard' nucleophiles attacking C-2 of the dienyl ligand. The diene complexes 10 resulting from C-1 addition can be reactivated by hydride abstraction with Ph//3C** plus PF//6** minus , to give dienyl complexes 11, which undergo a second nucleophile addition regio- and stereospecifically (trans to the Fe(CO)//2L group). Decomplexation is easily accomplished, leading to cycloheptadienylacetic acid derivatives.