AbstractMono α‐acylation of acetone has been achieved for the first time by reacting with bench‐stable acyl azolium salts under violet‐LED light at room temperature. The intermolecular hydrogen atom transfer (HAT) from acetone to triplet state of azolium salts under violet LED irradiation resulted in thermodynamically less favourable (Z)‐α,β‐unsaturated ketones with up to 99 : 1 selectivity via C−C bond formation. This compelling protocol access the desired α‐C(sp3)−H acylation product under metal‐, ligand‐ and oxidant‐free conditions on a wide range of substrates.
摘要在室温紫外 LED 灯下,通过与台式稳定的酰基唑盐反应,首次实现了丙酮的单α-酰化。在紫光 LED 的照射下,分子间氢原子转移(HAT)从丙酮转移到三重态的偶氮鎓盐,通过 C-C 键的形成产生热力学上较不利的 (Z)-α,β-不饱和酮,其选择性高达 99 :1 的选择性。在无金属、配体和氧化剂的条件下,这一引人注目的方法可在多种底物上获得所需的α-C(sp3)-H酰化产物。