A green and sustainable visible light-mediated deoxygenative amidation protocol to generate acyl radicals from commercially available carboxylic acids is described. The cheap, commercially available and user friendly organic photoredox catalyst rhodamine B could be employed in dipeptide and amide coupling reactions under metal-free conditions and visible light irradiation. This method showed excellent functional group selectivity for the formation of peptide bonds or amide bonds without affecting other functional groups such as alcohols, amides, halogens and heterocycles. This protocol was suitable for use in challenging amide coupling reactions involving hindered carboxylic acids with low nucleophilic amines. This operationally straightforward method boosts the efficient synthesis of various dipeptides and amides in moderate to good yields (55–89%).

中文翻译：

---

用于合成二肽和酰胺的可见光诱导脱氧酰胺化方案


描述了一种绿色且可持续的可见光介导的脱氧酰胺化方案，用于从市售羧酸产生酰基自由基。廉价、市售且用户友好的有机光氧化还原催化剂罗丹明 B 可用于无金属条件和可见光照射下的二肽和酰胺偶联反应。该方法对肽键或酰胺键的形成表现出优异的官能团选择性，而不影响其他官能团，如醇、酰胺、卤素和杂环。该方案适用于涉及具有低亲核胺的受阻羧酸的具有挑战性的酰胺偶联反应。这种操作简单的方法提高了各种二肽和酰胺的有效合成，产率中等至良好（55-89%）。