An Immobilized‐Dirhodium Hollow‐Fiber Flow Reactor for Scalable and Sustainable C−H Functionalization in Continuous Flow

Chun‐Jae Yoo, Daniel Rackl, Wenbin Liu, Caroline B. Hoyt, Brian Pimentel, Ryan P. Lively, Huw M. L. Davies and Christopher W. Jones

Angew. Chem. Int. Ed.,
2018, 57, 34, 10923-10927; DOI:10.1002/anie.201805528

06/2018

This collaborative report from the Jones and Davies Groups introduces a novel flow reactor systems to harness the potential of carbene C–H insertion transformations in flow.

This scalable flow reactor is demonstrated for enantioselective and regioselective rhodium carbene reactions (cyclopropanation and C−H functionalization) by developing cascade reaction methods employing a microfluidic flow reactor system containing immobilized dirhodium catalysts in conjunction with the flow synthesis of diazo compounds. This allows the utilization of the energetic diazo compounds in a safe manner and the recycling of the dirhodium catalysts multiple times.

This approach is amenable to application in a bulk‐scale synthesis employing asymmetric C−H functionalization by stacking multiple fibers in one reactor module. The products from this sequential flow–flow reactor are compared with a conventional batch reactor or flow–batch reactor in terms of yield, regioselectivity, and enantioselectivity.

Author: Chunjae Yoo