Mangaonkar Saeesh R, Hayashi Hiroki, Kanna Wataru, Debbarma Suvankar, Harabuchi Yu, Maeda Satoshi, Mita Tsuyoshi
Institute for Chemical Reaction Design and Discovery (WPI-ICReDD), Hokkaido University, Kita 21, Nishi 10, Kita-ku, Sapporo, Hokkaido 001-0021, Japan.
JST, ERATO Maeda Artificial Intelligence in Chemical Reaction Design and Discovery Project, Kita 10, Nishi 8, Kita-ku, Sapporo, Hokkaido 060-0810, Japan.
Precis Chem. 2024 Feb 16;2(3):88-95. doi: 10.1021/prechem.3c00117. eCollection 2024 Mar 25.
γ-Butyrolactone structures are commonly found in various natural products and serve as crucial building blocks in organic synthesis. Consequently, the development of methods for synthesizing γ-butyrolactones has garnered significant interest within the organic synthesis community. In this study, we present a direct and highly efficient approach for the synthesis of γ-butyrolactones from allylic alcohols. Notably, this study represents the first instance of γ-butyrolactone synthesis initiated by radical hydrocarboxylation using CO , generated from metal formates, followed by cyclization. This two-step process is achieved through the synergistic interaction of photoredox and hydrogen atom transfer (HAT) catalysis, resulting in the production of γ-butyrolactones with exceptional efficiency. Additionally, when employing α,α-diaryl allylic alcohol derivatives as substrates, the reaction involves 1,2-aryl migration, which occurs concomitantly with CO addition, leading to the formation of 4,5-substituted lactones in a good yield. The artificial force induced reaction (AFIR) method identified the preferred 1,2-aryl migration pathway along with potential byproduct pathways, in which the targeted 1,2-migration was found to be the most plausible pathway.
γ-丁内酯结构常见于各种天然产物中，是有机合成中的关键结构单元。因此，γ-丁内酯的合成方法开发在有机合成领域引起了广泛关注。在本研究中，我们提出了一种从烯丙醇直接高效合成γ-丁内酯的方法。值得注意的是，本研究是首例通过金属甲酸盐产生的CO进行自由基氢羧化引发，随后环化来合成γ-丁内酯的实例。这个两步过程通过光氧化还原和氢原子转移（HAT）催化的协同作用实现，以极高的效率生成γ-丁内酯。此外，当使用α,α-二芳基烯丙醇衍生物作为底物时，反应涉及1,2-芳基迁移，该迁移与CO加成同时发生，从而以良好的产率形成4,5-取代的内酯。人工力诱导反应（AFIR）方法确定了优选的1,2-芳基迁移途径以及潜在的副产物途径，其中目标1,2-迁移被发现是最合理的途径。
