New mixed metal (Mn/Cu) catalyzed stereoselective cyclizations

Article abstract of DOI:10.1016/0040-4039(96)01249-X

Unsaturated alkyl bromides of type 1 undergo a stereoselective ring closure when treated with a MnBr₂ (5 mol%)/CuCl (3 mol%) catalytic mixed metal system and diethylzinc at 60°C in DMPU affording five membered carbo- and heterocycles. An alternative Ni-catalyzed cyclization of bromoalkylketones is also described. Remarkably in this case, the iodine-zinc exchange could be performed with EtZnBr instead of pyrophoric Et₂Zn.