Iron-Catalyzed Synthesis Of Allylic Boronates

Allylboronate,a useful organoboron reagent,represent exceedingly versatile building block for organic synthesis that undergo C-C,C-N,C-O bond formation in catalytic reaction.As a kind of important allylation reagents,allylboronate can introduce an allyl group and increase the locus can decorate in organic molecules.In addition,allylboronates are widely used in organic synthesis.Therefore,synthesis of allylboronate with functional diversity has great significance.Herein,we describe the synthesis of allylic boronates via FeCl2-catalyzed boration of allyl alcohol and its derivatives with B2pin2.Having tolerance toward different substitution patterns and functional groups,the iron-catalyzed reaction would serve as a useful method for the synthesis of various allylic boronates.1)Using FeCl2/PPh3 as catalyst,in the presence of t-BuOK,the reaction between B2pin2 and allyl carbonate afforded allylic boronates.Having tolerance toward different substitution patterns and functional groups,such as halogen,ring,long chain hydrocarbon,etc.,the iron-catalyzed reaction would serve as a useful method for the synthesis of various allylic boronates in good yield.2)Using FeCl2/(n-Bu)3P as catalyst,in the presence of t-BuOK and H3BO3,the reaction between B2pin2 and allyl alcohol afforded allylic boronates.This method can be applied to the synthesis of a variety of allylic boronates.And these products can be easily separated in moderate yield.