Enantioselective One-Pot Synthesis of Cyclopropane-Fused Tetrahydroquinolines via a Ru-Catalyzed Intramolecular
Tetsuya Tsujihara1, Koki Nishino1, Wakaba Miura1
1Department of Medicinal and Organic Chemistry, School of Pharmacy, Iwate Medical University, Yahaba, Iwate 028-3694, Japan.
Abstract:
A highly enantioselective one-pot synthesis of cyclopropane-fused tetrahydroquinolines bearing carbonyl functionalities, which are difficult to synthesize using conventional methods, is reported. Employing readily accessible alkene-tethered anthranilaldehydes, hydrazone formation and subsequent Ru-catalyzed intramolecular cyclopropanation furnish the desired products in ≤87% yield and ≤95% ee under mild conditions. Various anthranilaldehydes, functionalized alkenes, and N-aryl sulfonyl groups are tolerated, and a series of synthetic transformations were conducted to demonstrate the practical utility.
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