- Stereoselective construction of a berberine C-8 benzyl group for the synthesis of javaberine derivatives
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Diastereoselective synthesis of 8-benzyltetrahydroprotoberberines was examined. Although Stevens rearrangement of N-benzylxylopinine resulted in poor yield and diastereoselectivity, benzylation of tetracyclic iminium successfully gave H8-H14 trans-benzyltetrahydroprotoberberines with high stereoselectivity.
- Kakigi, Rina,Nakano, Mai,Ueno, Ayana,Miyawaki, Akari,Tomioka, Kiyoshi,Yamamoto, Yasutomo
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p. 512 - 523
(2020/01/31)
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- Mn(II)-Catalyzed N -Acylation of Amines
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A practical protocol has been developed here for the Mn(II)-catalyzed N -acylation of amines with high yields using N, N -dimethylformamide and other amides as the carbonyl source. The protocol is simple, does not require any acid, base, ligand, or other additives, and encompasses a broad substrate scope for primary, secondary, and heterocyclic amines.
- Ma, Juan,Zhang, Jingyu,Gong, Hang
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p. 693 - 703
(2019/01/23)
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- An unprecedented 1,8a-bond fission of an N-formyl-1,2,3,4- tetrahydroisoquinoline derivative under A nitration condition
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An unprecedented bond fission between the 1 and 8a positions of an N- formyl-1,2,3,4-tetrahydroisoquinoline derivative was observed under nitration conditions using nitric acid and acetic acid. The structures of the products and the proposed reaction mechanism were also described.
- Honda, Toshio,Nishimura, Masato,Itabashi, Jun,Kanai, Kazuo
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p. 1121 - 1128
(2007/10/03)
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- A new regioselective synthesis of isopavine and pavine alkaloids via double cyclization of N-(1,2-diarylethyl)-N-(2-phenylsulfinylethyl)formamide
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Pummerer reaction of N-[1,2-(3,4-dimethoxyphenyl)ethyl]-N-(2-phenylsulfinylethyl)formamide (9) using trifluoroacetic anhydride and boron trifluoride etherate caused double cyclization to give N-formylisopavine (21). Acid catalyzed cyclization of the 1,2-dihydroisoquinoline (23) prepared from 4-phenylthio-1,2,3,4-tetrahydroisoquinoline (11) gave N-formylpavine (26). LiAlH4 reduction of the N-formates (21 and 26) gave (±)-O-methylthalisopavine (4) and (±)-argemonine (5), respectively.
- Shinohara, Tatsumi,Takeda, Akira,Toda, Jun,Sano, Takehiro
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p. 981 - 992
(2007/10/03)
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