电化学催化的吩噻嗪与萘酚的芳基化反应

电化学有机合成将电解过程与传统有机合成相结合，具备反应高效、条件温和、原子经济性高等诸多优点，深受合成化学家的青睐，于近年来得到了快速发展，是一项有广大应用前景的新兴绿色化学技术。

N-芳基吩噻嗪与联芳基二酚均是在有机合成化学及材料化学领域得到广泛应用的明星分子，其合成策略受到人们的密切关注与深入研究。然而，已发展的合成手段仍有一定的局限性，如使用当量的氧化剂、原子经济性差、底物范围窄等，因此开发其高效合成方法仍具备重要的研究价值与现实意义。

本文以开发新型电化学合成技术为目的，发展了电化学芳基化反应，实现了N-芳基吩噻嗪与联芳基二酚骨架的快速构筑，反应均具备优异的产率及底物适用性。在电化学催化的吩噻嗪芳基化反应中，高效完成了吩噻嗪与萘胺的交叉脱氢偶联，产率高达98%，借助循环伏安及电子顺磁共振实验提出了可能的自由基反应机理。目标产物不仅可替代商用的N-苯基吩噻嗪光敏剂，也能一步转化为有机磷光材料客体分子，均表现出优秀的实际性能，凸显出该合成策略在有机化学与材料科学领域的应用潜力。

萘酚的电化学芳基化反应在碱的催化下生成联芳基二酚，产率高达88%。引入金鸡纳碱衍生物作为手性催化剂可实现该反应的不对称控制，合成轴手性联芳基二酚化合物，对映选择性最高可达65%，为电化学合成技术与不对称催化的融合发展提供了可靠范例。

Electrochemical organic synthesis combines electrolysis with traditional organic synthesis and features advantages, such as high reaction efficiency, mild conditions and high atom economy. It has been increasingly adopted by synthetic chemists and rapidly developed in recent years as a sustainable technology with vast uncharted potential.

Both N-aryl phenothiazines and biaryldiols are privileged molecules with a wide range of applications in organic synthetic chemistry and materials chemistry. Despite the substantial research focuses and advancements, the developed synthetic routes still suffer from some limitations, including the use of stoichiometric oxidants, inferior atom economy and poor substrate scopes. Therefore, it is of great scientific value and utility to develop novel and efficient synthetic alternatives.

In this thesis, with the purpose of exploring innovative electrochemical synthetic techniques, novel electrochemical arylation reaction was developed to synthesize N-aryl phenothiazines and biaryldiols efficiently, as reflected by the excellent yields and substrate scopes. The cross-dehydrogenative coupling of phenothiazines with naphthylamines was successfully accomplished in electrocatalytic arylation of phenothiazines with up to 98% yield, and a plausible radical mechanism was proposed based on cyclic voltammetry and electron paramagnetic resonance experiments. The target products could be used not only as better photocatalysts than commercially available N-phenyl phenothiazine, but also as guest molecules for organic phosphorescent materials after one-step conversion. Both applications showed superior performance, which revealed the great potential of this synthetic strategy for applications in organic chemistry and materials chemistry.

In other development, a base-catalyzed electrochemical arylation of naphthols has been accomplished to obtain biaryldiols with up to 88% yield. Furthermore, by introducing cinchona alkaloids as the chiral catalyst, the corresponding asymmetric manifold was also investigated to synthesize axially chiral biaryldiols with up to 65% enantiomeric excess, which provided a reliable model for integrating electrochemical synthesis with asymmetric catalysis.

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