- Rapid route to 3,4-substituted indoles via a directed ortho metalation-retro-Mannich sequence.
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[reaction: see text] In the presence of NXS (X = Br, I, Cl), gramine derivatives 1, derived by combined directed ortho metalation (DoM)-cross-coupling sequences, rapidly undergo retro-Mannich fragmentation (2) to afford 3-halo indoles 3 in 37-88% yields.
- Chauder, Brian,Larkin, Andrew,Snieckus, Victor
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p. 815 - 817
(2007/10/03)
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- Tryptamine analogues, their synthesis and their use as 5-HT1 -like or 5-HT2 receptor agonists
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The present invention relates to known and novel tryptamine analogues, processes and intermediates useful in their preparation, pharmaceutical compositions containing them and their use in therapy, in particular for the treatment and/or prophylaxis of dis
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- DIRECTED LITHIATION OF 1-TRIISOPROPYLSILYLGRAMINE. A SHORT ACCESS TO 3,4-DISUBSTITUTED INDOLES
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1-Triisopropylsilylgramine was lithiated regioselectively at C-4 by treatment with t-BuLi in ether at 0 deg C for 1 h.The lithiated species was trapped with a variety of electrophiles to furnish 4-functionalized gramine derivatives in good yields.Replacement of the triisopropylsilyl protecting group by a methyl group resulted in C-2 selective lithiation under the similar reaction conditions.
- Iwao, Masatomo
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