Visible-light-promoted Fe photocatalysis is a sustainable strategy for synthetic chemistry. Yet, the adoption of Fe photocatalytic reactions proceeding through a ligand-to-metal charge transfer event has been limited to simple substrates in many transformations. An outstanding challenge in the field is the selection of tunable ligand scaffolds providing general reactivity. In this work, we describe the use of aliphatic amines as ligands in Fe-promoted decarboxylative Giese-type additions. Unlike prior photoredox reports, this method enables the coupling of substrates with free amines, alcohols, and a boronic ester. To gain insight into the role of diethylenetriamine (L1), ligated Fe salts were investigated using ultraviolet-visible spectroscopy, thermal gravimetric analysis, and density functional theory. These studies support the formation of a photoactive octahedral carboxylate (L1)Fe(OCOR)3. As an increasing number of photocatalytic reactions proceed using earth-abundant metals, the use of these ligands expands the possibility of applying Fe to a broad array of transformations.

中文翻译：

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Fe 光催化 Gese 型添加物中的变革性配体效应


可见光促进的 Fe 光催化是合成化学的一种可持续策略。然而，在许多转化中，通过配体到金属电荷转移事件进行的 Fe 光催化反应的采用仅限于简单的衬底。该领域的一个突出挑战是选择具有一般反应性的可调配体支架。在这项工作中，我们描述了脂肪胺作为配体在 Fe 促进的脱羧 Gese 型加成剂中的使用。与之前的光氧化还原报告不同，该方法能够使底物与游离胺、醇和硼酯偶联。为了深入了解二乙烯三胺 （L1） 的作用，使用紫外-可见光谱、热重分析和密度泛函理论研究了连接的 Fe 盐。这些研究支持光活性八面体羧酸盐 （L1）Fe（OCOR）3 的形成。随着越来越多的光催化反应使用地球上丰富的金属进行，这些配体的使用扩大了将 Fe 应用于广泛转化的可能性。