Four decarboxylative conjugate radical addition methods, including recent and greener methods using Fe- and Eosin Y as photocatalysts, were examined using Seebach-Beckwith dehydroalanine as a radical acceptor. Head-to-head comparison of yields and purity suggests that Ir-photocatalyzed decarboxylation of carboxylic acids is the optimal method for syntheses involving resonance-stabilized radicals. However, approaches relying on cheaper Ni-, Fe-, and Eosin Y-catalyzed processes are quite viable for the conjugate addition of 1°, 2°, and 3° radicals.

中文翻译：

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金属和有机催化脱羧自由基将羧酸加成到 Seebach-Beckwith 脱氢丙氨酸中对光学纯非天然氨基酸的研究和优化


使用脱氢丙氨酸作为自由基受体的 Seebach-Beck 研究了四种脱羧偶联自由基加成方法，包括使用 Fe- 和伊红 Y 作为光催化剂的最新和更绿色的方法。产率和纯度的头对头比较表明，Ir 光催化羧酸脱羧是涉及共振稳定自由基合成的最佳方法。然而，依赖于更便宜的 Ni-、Fe-和曙红 Y 催化过程的方法对于偶联添加 1°、2° 和 3° 自由基是相当可行的。