Indium Mediated Barbier Reaction of Ninhydrin and Isatin

and Cd7 have been used. Among them the use of indium in aqueous solution has shown considerable promise in the addition of allylic halides to the carbonyl groups.2 Some fragmental examples on the indium-mediated Barbier reaction of isatin derivatives have been reported.8 Although the products derived from the Barbier reaction of isatins or ninhydrins have highly functionalized interesting structures,9 the reactions have not been studied systematically.8 Thus, we intended to examine systematically on the indium mediated Barbier reaction of ninhydrin and isatin with allyl bromide, methallyl bromide and benzyl bromide. The reaction of ninhydrin (1) and benzyl bromide occurred at the 2-position of ninhydrin selectively to give 2a in 39% yield. We used typical experimental conditions for the indium-mediated Barbier reactions: Use of indium metal i