AbstractDihydroquinazolinone (DHQZ) has recently been harnessed as a ketone‐derived pro‐aromatic reagent extensively employed in (metalla)photoredox reactions as versatile group transfer agents. In this work, we outline a column chromatography‐free protocol for the multigram‐scale synthesis of pro‐aromatic DHQZs as well as its use in a gram‐scale nickel/photoredox dual‐catalyzed cross‐coupling in single‐batch, photoflow, and simultaneous multiple smaller batches. While the single‐batch approach leveraged moderate yields, a simple plug‐flow photoreactor also exhibited amenable productivity (up to 45 % yield) despite the use of a heterogeneous base. Meanwhile, performing the metallaphotoredox‐catalyzed reaction in multiple smaller batches in an improvised photoreactor facilitated high yields of up to 59 % and good reproducibility, implying a convenient alternative in the absence of photoflow setups.
摘要 二氢喹唑啉酮(DHQZ)作为一种酮衍生的原芳香族试剂,最近被广泛应用于(金属)光氧化反应中,成为多功能的基团转移剂。在这项工作中,我们概述了一种多克级原芳香族 DHQZ 的无柱色谱合成方案,以及其在克级镍/光氧双催化交叉偶联中的应用,包括单批、光流和同时多批较小批量的合成。单批次方法的产率适中,而简单的塞流式光反应器尽管使用了异质基,但也表现出了良好的生产率(产率高达 45%)。同时,在简易光反应器中进行金属光氧催化反应时,可同时进行多个较小批量的反应,从而获得高达 59% 的高产率和良好的可重复性,这意味着在没有光流装置的情况下,这是一种方便的替代方法。