Direct Synthesis of Benzofuro[2,3‐b]pyrroles through a Radical Addition/[3,3]‐Sigmatropic Rearrangement/Cyclization/Lactamization Cascade |
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Authors: | Dr Masafumi Ueda Yuta Ito Yuki Ichii Maiko Kakiuchi Hiroko Shono Prof Dr Okiko Miyata |
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Institution: | Kobe Pharmaceutical University, Motoyamakita, Higashinada, Kobe 658‐8558 (Japan), Fax: (+81)78‐441‐7554 |
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Abstract: | A straightforward synthetic method for the construction of benzofuro2,3‐b]pyrrol‐2‐ones by a novel domino reaction through a radical addition/3,3]‐sigmatropic rearrangement/cyclization/lactamization cascade has been developed. The domino reaction of O‐phenyl‐conjugated oxime ether with an alkyl radical allows the construction of two heterocycles with three stereogenic centers as a result of the formation of two C?C bonds, a C?O bond, and a C?N bond in a single operation, leading to pyrrolidine‐fused dihydrobenzofurans, which are not easily accessible by existing synthetic methods. Furthermore, asymmetric synthesis of benzofuro2,3‐b]pyrrol‐2‐one derivatives through a diastereoselective radical addition reaction to a chiral oxime ether was also developed. |
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Keywords: | domino reaction heterocycles radical reactions rearrangement synthetic methods |
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