Zhao Gaoyuan, Mukherjee Upasana, Yao Wang, Ngai Ming-Yu
James Tarpo Jr. and Margaret Tarpo Department of Chemistry, Purdue University, West Lafayette, Indiana 47907, United States.
Department of Chemistry, State University of New York, Stony Brook, New York 11790, United States.
Acc Chem Res. 2025 Jun 3;58(11):1815-1829. doi: 10.1021/acs.accounts.5c00205. Epub 2025 May 22.
ConspectusRadical migration represents a powerful strategy for reaction discovery and development in organic synthesis, offering access to unprecedented functional molecules and chemical space. In this Account, we describe our contributions to the field, particularly focusing on 1,2-radical acyloxy migration (RAM), a process involving the transposition of a radical and an acyloxy group. We highlight its application in carbohydrate modification and allyl carboxylate trifunctionalization, demonstrating how this reactivity enables the streamlined synthesis of novel glycomimetics and facilitates selective 1,2,3-trifunctionalization of allyl carboxylates. These advances establish 1,2-RAM as a versatile platform for catalytic radical transformations, unlocking new opportunities in reaction development and functional molecule design.Our approach leverages excited-state palladium and ground-state nickel catalysis to modify carbohydrates, specifically at the C2 position. This strategy enables C2-deoxy-hydrogenation, deuteration, iodination, alkenylation, allylation, ketonylation, and arylation reactions, providing direct access to unprecedented glycomimetics. These transformations streamline the synthesis of structurally diverse glycomimetics, facilitating the discovery and development of carbohydrate-based functional molecules. Furthermore, the mild reaction conditions and high functional group tolerance of these catalytic systems make them particularly attractive for late-stage functionalization, broadening their applicability in complex molecule synthesis.Beyond carbohydrates, we have extended 1,2-RAM reactivity to achieve unprecedented 1,2,3-trifunctionalization of allyl carboxylates. By employing excited-state phosphine catalysis, we demonstrate a 1,3-carbobromination reaction accompanied by an acyloxy shift. This proof-of-concept study lays the foundation for developing a broader range of 1,2,3-trifunctionalization reactions, effectively transforming allyl carboxylates into substituted isopropyl carboxylate donors. This advancement expands the synthetic utility of allyl carboxylates, enabling the rapid construction of structurally diverse molecular scaffolds.In summary, the 1,2-RAM reactivity opens a new avenue for reaction discovery and development, granting access to new functional molecules and chemical space. The mild conditions, broad functional group compatibility, and unique reactivity of this approach make it a valuable tool for chemical synthesis. We anticipate that merging 1,2-RAM with other catalytic platforms will further advance bond disconnection strategies, provide access to new functional molecules, and expand the frontiers of chemical synthesis.
综述
自由基迁移是有机合成中反应发现与开发的一项有力策略,能够获得前所未有的功能分子和化学空间。在本综述中,我们描述了我们在该领域的贡献,特别关注1,2-自由基酰氧基迁移(RAM),这是一个涉及自由基和酰氧基转位的过程。我们强调了其在碳水化合物修饰和烯丙基羧酸酯三官能团化中的应用,展示了这种反应性如何实现新型糖模拟物的简化合成,并促进烯丙基羧酸酯的选择性1,2,3-三官能团化。这些进展确立了1,2-RAM作为催化自由基转化的通用平台,为反应开发和功能分子设计带来了新机遇。
我们的方法利用激发态钯和基态镍催化来修饰碳水化合物,特别是在C2位。该策略能够实现C2-脱氧氢化、氘代、碘化、烯基化、烯丙基化、酮基化和芳基化反应,直接获得前所未有的糖模拟物。这些转化简化了结构多样的糖模拟物的合成,促进了基于碳水化合物的功能分子的发现与开发。此外,这些催化体系温和的反应条件和高官能团耐受性使其在后期官能团化中特别有吸引力,拓宽了它们在复杂分子合成中的应用范围。
除了碳水化合物,我们还扩展了1,2-RAM反应性,实现了烯丙基羧酸酯前所未有的1,2,3-三官能团化。通过采用激发态膦催化,我们展示了一个伴随酰氧基迁移的1,3-碳溴化反应。这项概念验证研究为开发更广泛的1,2,3-三官能团化反应奠定了基础,有效地将烯丙基羧酸酯转化为取代的异丙基羧酸酯供体。这一进展扩展了烯丙基羧酸酯的合成效用,能够快速构建结构多样的分子骨架。
总之,1,2-RAM反应性为反应发现与开发开辟了一条新途径,能够获得新的功能分子和化学空间。这种方法温和的条件、广泛的官能团兼容性和独特的反应性使其成为化学合成的宝贵工具。我们预计将1,2-RAM与其他催化平台相结合将进一步推进键断裂策略,获得新的功能分子,并拓展化学合成的前沿领域。