A Stereoselective Hydroamination Transform To Access Polysubstituted Indolizidines

Shenvi et. al have reported a diastereo- and regioselective hydroamination of simple dienamines in an anti-Markovnikov manner to give polysubstituted indolizidine alkaloids. They have demonstrated that the highly stereoselective double hydroboration step of the dienamines and dimethyl sulfide borane proceed using iodine as an activator. And the following carbon-nitrogen bond-forming step appears to proceed by the borinic amide intermediate to get leaving ability followed by alkyl rearrangement from the boron to nitrogen. Finally, they have converted them into the indolizidines using an intramolecular Mitsunobu reaction.