Carbophilic 3-Component Cascades: Access to Complex Bioactive Cyclopropyl Diindolylmethanes

Naturally occurring indole-3-carbinol and 3,3-diindolylmethane show bioactivity in a number of disparate disease areas, including cancer, prompting substantial synthetic analogue activity. We describe a new approach to highly functionalised derivatives that starts from allene gas and proceeds via the combination of a three-component Pd0-catalysed cascade with a one-pot, three-component carbophilic PtII cascade linked to a stereoselective acid-catalysed MannichMichael reaction that generates complex cyclopropyl diindolylmethanes which show selective activity against prostate cancer cell lines.