A selective Cu(II)/Fe(III)-mediated hydrogenation of steroidal haloalkenes in the presence of hydrazine

A new system for hydrogenation of haloalkenes is reported. Cu(II)/Fe(III)-mediated selective hydrogenation of steroidal haloalkenes in the presence of hydrazine proves to be a very efficient method for the synthesis of 17β-halosteroids, potential candidates as antiestrogens or androgen receptor-mediated imaging agents. The reaction stereospecifically affords β-haloalkanes without any concomitant formation of dehalogenation products.