Continuous Flow Synthesis of Spiro[fluorene‐9,9′‐Xanthene] Serving as the Organic Light Emitting Diode Emitters and Organic Semiconductors for Kilogram‐Scale Production With Flexible and Controllable Selectivity

Continuous flow chemistry allows for the low‐cost and eco‐friendly mass production of organic semiconductors. Although spiro[fluorene‐9,9′‐xanthene] derivatives (SFXs) serve as a role of steric hindrance for the function of stability in OLED technology that has been industrialized and commercialized, it does not investigate their chemical engineering based on the “Huang‐Xie method” with continuous flow synthesis technology to achieve scalable production. Herein, we report that kilogram‐scale production with exceptional product selectivity (90% for SFX and 100% for BPF) with high throughput rates (648.48 g/h for SFX, 997.62 g/h for BPF). Compared with conventional batch processes, the continuous flow approach for SFX synthesis achieved a 25.48% reduction in raw material costs, solid waste generation by 45.79%, and a 68% shortening of production time. This technology exhibited remarkable environmental advantages, yielding an E‐factor of 1.54 kg/kg and a process mass intensity (PMI) of 2.54 kg/kg, representing 94.7% and 91.5% reductions relative to batch processes. Using an upgraded continuous flow platform, we also synthesized high‐performance optoelectronic materials SFX‐TRZ (84% yield) and BPFG (92.5% yield) from SFX and BPF precursors. This work opens continuous flow synthesis for organic semiconductors with advanced green chemistry principles.