Highly efficient and clean synthesis of 1-amino-2-acetylanthraquinone by copper-catalyzed reductive cleavage of isoxazole motif
作者:Zhongkui Zhao、Renzhi Li、Yu Li
DOI:10.1016/s1872-2067(12)60743-8
日期:2014.3
Abstract A clean and highly efficient synthesis of 1-amino-2-acetylanthraquinone via reductive isoxazole ring cleavage of 3-methylanthra[1,2-c]isoxazole-6,11-dione catalyzed by trace copper using hydrazine hydrate as a clean reducing agent and water as a green reaction medium under mild reaction conditions was investigated. Various transition-metal catalysts were screened for the reductive ring-opening
摘要 以水合肼为清洁还原剂,通过痕量铜催化 3-甲基蒽[1,2-c]异恶唑-6,11-二酮的还原异恶唑环裂解,清洁高效合成 1-氨基-2-乙酰蒽醌并在温和的反应条件下研究了水作为绿色反应介质。为还原开环反应筛选了各种过渡金属催化剂,结果表明 Cu(NO3)2 是一种极好的催化剂。在 2.6 mol% Cu(NO3)2(周转数 38)和 1.3 当量的存在下,获得了 97.2% 的转化率和大于 95% 的 1-氨基-2-乙酰蒽醌选择性。水合肼在水中 2 小时。产物结构经1H核磁共振波谱和质谱确证;主要副产品是羟基取代的 1-氨基-2-乙酰蒽醌。提出了铜催化 3-甲基蒽[1,2-c]异恶唑-6,11-二酮与水合肼开环的可能反应机理。