Organometallic reactions in aqueous media : reactivity, selectivity and synthetic applications

Because of the concern for the environment and the search for the synthetic efficiency, the metal-mediated aqueous carbon-carbon bond formation reactions were studied. By employing sulfonimines, the scope of the metal-mediated aqueous Barbier-type allylation reactions was expanded to C=N electrophiles and the regio- and stereoselectivities of these reactions were examined.The stereochemical factors in the indium-mediated aqueous Barbier-type allylation reactions of sulfonimines were investigated, and chelation control was observed and applied in the stereoselective crotylation reactions. By using chiral-modified sulfonimines or sulfinimines, the asymmetric aqueous Barbier-type allylation reaction of C=N electrophiles was also studied.Highly regioselective propargylation reactions of sulfonimines mediated by zinc were discovered through the coupling of propargylic bromides with sulfonimines in aqueous media. Beyond the allylation transformations, zinc was also found as the metal of choice for the mediation of the Barbier-type benzylation reaction of sulfonimines and the coupling reaction of aldehydes with alpha-bromoacetonitriles in aqueous media.The indium-mediated aqueous coupling reaction of 1,4-dibromobut-2-yne with aldehydes was demonstrated to be a concise way for the synthesis of 1,3-dien-ol compounds. Further synthetic applications of this reaction including the intro-molecular Diels-Alder reactions were preliminarily studied