Synthesis and Catalytic Property of Iron Pincer Complexes Generated by C_sp³–H Activation

Abstract

When the diphosphinito PCP ligand (Ph 2 P(C 6 H 4 )) 2 CH 2 ( 1 ) was treated with Fe(PMe 3 ) 4 and FeMe 2 (PMe 3 ) 4, the C sp 3 –H activation products [(Ph 2 P(C 6 H 4 )) 2 CH]Fe(H)(PMe 3 ) 2 ( 2 ) and [(Ph 2 P(C 6 H 4 ))(PhP(C 6 H 4 ) 2 )CH]Fe(PMe 3 ) 2 ( 3 ) were obtained at room temperature. The generation of product 3 underwent one C sp 3 –H and one C sp 2 –H bond activation process. The new iron hydride complex 2 showed good activity in the catalytic hydrosilylation of aldehydes and ketones by using (EtO) 3 SiH as the hydrogen source under mild conditions. Complexes 2 and 3 were characterized by spectroscopic methods and X-ray diffraction analysis.