- Development of an Alkyne Analogue of the de Mayo Reaction: Synthesis of Medium-Sized Carbacycles and Cyclohepta[b]indoles
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Embedded medium-sized carbacycles and cyclohepta[b]indoles occur frequently as scaffold elements in natural products and bioactive compounds. Described herein is a conceptionally novel photochemically triggered cascade process to these scaffolds. Key to the cascading ring-expansion process is an unprecedented intramolecular alkyne analogue of the de Mayo reaction.
- Tymann, David,Tymann, Dina Christina,Bednarzick, Ulf,Iovkova-Berends, Ljuba,Rehbein, Julia,Hiersemann, Martin
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supporting information
p. 15553 - 15557
(2018/11/10)
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- Synthesis of multi-substituted dihydrofurans via palladium-catalysed coupling between 2,3-alkadienols and pronucleophiles
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Multi-substituted dihydrofurans were obtained from a palladium-catalysed coupling reaction between 2,3-alkadienols and ketones bearing an electron-withdrawing group at the α-position. Methanol as a solvent was essential for the initial dehydrative substitution to suppress the competitive hydroalkylation of the diene moiety. The substitution would be followed by intramolecular hydroalkoxylation under the same catalysis.
- Tsukamoto, Hirokazu,Ito, Kazuya,Doi, Takayuki
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supporting information
p. 5102 - 5105
(2018/05/26)
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- A detailed investigation of the aza-prins reaction
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The development of a Lewis acid-promoted aza-Prins reaction to form piperidines and pyrrolidines is described. Indium trichloride has been found to be a highly successful and mild Lewis acid for promoting this reaction. A thorough mechanistic investigation is described, including the factors that influence the formation of the 5- or 6-membered ring product(s). The Royal Society of Chemistry.
- Dobbs, Adrian P.,Guesne, Sebastien J. J.,Parker, Robert J.,Skidmore, John,Stephenson, Richard A.,Hursthouse, Mike B.
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supporting information; experimental part
p. 1064 - 1080
(2010/06/13)
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- Synthesis of the C(1)-C(8) segment of (+)-acutiphycin
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The synthesis of the pyran segment of (+)-acutiphycin was achieved using an intramolecular Lewis acid-catalyzed reaction between a silyl enol ether and an ortho ester.
- Methot, Joey-Lee,Morency, Louis,Ramsden, Philip D.,Wong, Jerome,Léger, Serge
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p. 1147 - 1150
(2007/10/03)
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- Synthesis of 4,6-dideoxyfuranoses through the regioselective and diastereoselective oxyfunctionalization of a dimethylphenylsilyl-substituted chiral homoallylic alcohol
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The 4,6-dideoxyfuranoses 10a and 10b have been synthesized by starting from the readily available E-5-dimethylphenylsilyl-2-hexene-4-ol (1)and employing successively three versatile oxyfunctionalization methods, namely photooxygenation, metal-catalyzed epoxidation, and oxidative desilylation. Photooxygenation of the hydroxy vinylsilane 1 and subsequent triphenylphosphine reduction of the hydroperoxides 3 afford the like-4a and unlike-4b diols, which have been converted separately to the tetrahydrofurans (2S*,3R*,5R*)-7a and (2S*,3R*,5S*)-7b by a combination of diastereoselective epoxidation and regioselective intramolecular epoxide-ring opening. In the epoxidation reaction, catalyzed by Ti(OiPr)4 or VO(acac)2, only one diastereomer (dr > 95:5) of the epoxide 5 is obtained. Further intramolecular opening of the epoxide ring in erythro-5 occurs regioselectively at the C-α position and diastereoselectively under inversion of the configuration of the silyl-substituted stereogenic center to generate only one diastereomer of the tetrasubstituted tetrahydrofurans 7. Oxidative desilylation of the latter gave the hitherto unknown 4,6-dideoxyfuranoses 10a and 10b. The use of the optically active E-5-dimethylphenylsilyl-2-hexene-4-ol (1) as starting material, which is readily available through lipase-catalyzed kinetic resolution, leads to the D- and L-4,6-dideoxysorbofuranoses 10a and D- and L-4,6-dideoxyfructofuranoses 10b in up to 98% enantiomeric excess.
- Adam,Saha-Moeller,Schmid
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p. 7365 - 7371
(2007/10/03)
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