An Enantioselective Hydrogenation of an Alkenoic Acid as a Key Step in the Synthesis of AZD2716

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• 作者：Staffan Karlsson ; Henrik Sörensen ; Sören M. Andersen ; Angele Cruz ; Per Ryberg
• 刊名：Organic Process Research & Development
• 出版年：2016
• 出版时间：February 19, 2016
• 年：2016
• 卷：20
• 期：2
• 页码：262-269
• 全文大小：552K
• ISSN：1520-586X

文摘

A classical resolution of a racemic carboxylic acid through salt formation and an asymmetric hydrogenation of an α,β-unsaturated carboxylic acid were investigated in parallel to prepare an enantiomerically pure alkanoic acid used as a key intermediate in the synthesis of an antiplaque candidate drug. After an extensive screening of rhodium- and ruthenium-based catalysts, we developed a rhodium-catalyzed hydrogenation that gave the alkanoic acid with 90% ee, and after a subsequent crystallization with (R)-1-phenylethanamine, the ee was enriched to 97%. The chiral acid was then used in sequential Negishi and Suzuki couplings followed by basic hydrolysis of a nitrile to an amide to give the active pharmaceutical ingredient in 22% overall yield.