Polymer monolith-supported dirhodium(II)-catalyzed continuous flow cyclopropanation in capillary format

Abstract

Herein, the first trial for the miniaturization of the dirhodium(II)-catalyzed cyclopropanation reaction is reported. Rh2(S-tertPTTL)4† was immobilized inside a capillary microreactor on a pyridine-derived monolithic support. The system demonstrated good stability with low leaching rate of the dirhodium(II) catalyst comparable to conventional packed solid support. The Rh2(S-tertPTTL)4-catalyzed cyclopropanation microreaction was carried out under continuous flow conditions generating the cyclopropane product in moderate yield (44%) and excellent diastereoselectivity (>20:1 E:Z dr).