Behbehani Haider, Ibrahim Hamada Mohamed
Chemistry Department, Faculty of Science, Kuwait University, P.O. Box 5969, Safat 13060, Kuwait.
Chemistry Department, Faculty of Science, Fayoum University, P.O. Box 63514, Fayoum, Egypt.
ACS Omega. 2019 Sep 4;4(12):15289-15303. doi: 10.1021/acsomega.9b02430. eCollection 2019 Sep 17.
An efficient method has been developed for the synthesis of uniquely substituted pyrazolo[1,5-]pyridine and pyrido[1,2-]indazole derivatives, which involves acetic acid and molecular oxygen promoted cross-dehydrogenative coupling reactions of respective β-ketoesters and β-diketones (like ethyl acetoacetate, ethyl benzoylacetate, methyl propionylacetate, acetylacetone, dimedone, 1,3-cyclohexanedione, and 1,3-cyclopentanedione) with -amino-2-iminopyridines. The proposed tentative mechanism involves formal acetic acid-promoted oxidative C(sp)-C(sp) dehydrogenative coupling followed by dehydrative cyclization under a catalyst-free condition within high atom economy processes.
已开发出一种高效合成独特取代的吡唑并[1,5 -]吡啶和吡啶并[1,2 -]吲唑衍生物的方法，该方法涉及乙酸和分子氧促进各自的β - 酮酯和β - 二酮（如乙酰乙酸乙酯、苯甲酰乙酸乙酯、丙酰乙酸甲酯、乙酰丙酮、二甲基环己二酮、1,3 - 环己二酮和1,3 - 环戊二酮）与2 - 氨基 - 2 - 亚氨基吡啶的交叉脱氢偶联反应。所提出的初步机理涉及在无催化剂条件下，在高原子经济性过程中，由乙酸促进的氧化C(sp)-C(sp)脱氢偶联，随后进行脱水环化。
