Syntheses of Sterically Bulky Schiff‐Base Magnesium Complexes and Their Application in the Hydrosilylation of Ketones

Abstract

The sterically bulky Schiff‐base ligand 1 (L1H) was treated with CH3MgI in toluene to give the unexpected homoleptic magnesium complex 2 (L1MgL1) in good yield. However, the reaction of sterically more bulky ligand 3 (L2H) with CH3MgI in diethyl ether yielded the desired heteroleptic magnesium iodide 4 [L2MgI(OEt2)], which was further reduced with sodium to produce the Mg–Na heterodimetallic complex 5. The crystal structures of all new magnesium complexes were determined by single‐crystal X‐ray diffraction. All new magnesium complexes have been investigated as catalysts for the hydrosilylation of ketones with (EtO)3SiH. The study showed that catalytic activity of the Mg–Na dimetallic complex 5 is superior to those of monometallic magnesium complexes 2 and 4 and is applicable to a series of subatrates.