Construction of Pseudo‐Heterochiral and Homochiral Di‐μ‐oxotitanium(Schiff base) Dimers and Enantioselective Epoxidation Using Aqueous Hydrogen Peroxide

Salen's lot: Meerwein–Ponndorf–Verley reduction of [Ti(salen)(OiPr)2] (salen=bis(salicylidene)ethylenediaminato) complexes followed by treatment with water leads to the synthesis of pseudo-heterochiral and homochiral di-μ-oxotitanium dimers. These dimers, in particular (aR,S,Δ, aR,S,Δ)-dimer 1, efficiently catalyze the epoxidation of simple olefins using aqueous hydrogen peroxide (see scheme) with ee values up to 99 % and turnover numbers up to 4600.