Modification of Iron(II) Tridentate Bis(imino)pyridine Complexes by a Boryl Group for the Production of α-Olefins at High Temperature

Abstract

A new series of boryl-substituted bis(imino)pyridine ligands [o-PinacolB-Ph-N═C(Me)-Py-C(Me)═N-Ph-o-BPinacol], Pinacol = (−O-(Me)2C−C(Me)2-O−) (6), [2,4,6-tri-Me-Ph-N═C(Me)-Py-C(Me)═N-Ph-o-BPinacol] (11), [4-bromo-2,6-di-Me-Ph-N═C(Me)-Py-C(Me)═N-Ph-o-BPinacol] (12), [2,4,6-tri-Me-Ph-N═C(Me)-Py-C(Me)═N-Ph-m-BPinacol] (14), [2,4,6-tri-Me-Ph-N═C(Me)-Py-C(Me)═N-Ph-p-BPinacol] (17), and [4-Bromo-2,6-di-Me-Ph-N═C(Me)-Py-C(Me)═N-Ph-p-BPinacol] (18), and their corresponding Fe(II) complexes [{o-PinacolB-Ph-N═C(Me)-Py-C(Me)═N-Ph-o-BPinacol}FeCl2] (3), [{2,4,6-tri-Me-Ph-N═C(Me)-Py-C(Me)═N-Ph-o-BPinacol}FeCl2] (19), [{4-bromo-2,6-di-Me-Ph-N═C(Me)-Py-C(Me)═N-Ph-o-BPinacol}FeCl2] (20), [{2,4,6-tri-Me-Ph-N═C(Me)-Py-C(Me)═N-Ph-m-BPinacol}FeCl2] (21), [{2,4,6-tri-Me-Ph-N═C(Me)-Py-C(Me)═N-Ph-p-BPinacol}FeCl2] (22), and [{4-bromo-2,6-di-Me-Ph-N═C(Me)-Py-C(Me)═N-Ph-p-BPinacol}FeCl2] (23) were synthesized. According to X-ray analysis, the introduction of boryl groups in the ortho-positions of the complex as in 3 caused the s...