Regioselective alkylation of carbohydrates and diols: a cheaper iron catalyst, new applications and mechanism†
Abstract
As an extension of our previous research on the regioselective protection of carbohydrates and diols, we developed an iron catalyst, Fe(dibm)3 (dibm = diisobutyrylmethane), which has an unusually broad catalytic scope in the selective monoalkylation of diols and carbohydrates. However, even though the iron reagent is green, the cost to prepare the catalyst is high, which is not conducive to large-scale application, and the mechanism of the catalytic reaction is still not completely clear. In this study, we have developed a much cheaper iron catalyst, Fe(dipm)3 (dipm = dipivaloylmethane), which has a similar catalytic efficiency in the regioselective alkylation of carbohydrates and diols. The mechanism of the iron-catalyzed selective alkylation was also studied and a new detailed reaction mechanism for the iron catalysis was proposed.