Transition-metal catalyzed asymmetric reactions under continuous flow from 2015 to early 2020

During last two decades, transition-metal catalyzed asymmetric reactions under continuous flow system have attracted a widespread attention. With its prominent advantages including higher safety and efficiency, precise control, better heat/mass transfer, easier scale-up and better sustainability, it has impressed both the academia and related industries. However, comparing with the prosperous development of transition-metal catalyzed asymmetric reactions in batch, utilization of this type of chemistry under continuous flow is still at an early stage. To inspire more potential industrial application and further studies of this chemistry in flow, this review summarized the recent advances of transition-metal catalyzed asymmetric reactions under continuous flow. Moreover, we further discussed the encountered challenges including reactor engineering, catalyst design, catalyst deactivation, pressure drop, clogging, side reactions etc., as well as their corresponding solutions and achievements in this mini-review.