- Unified Approach to Furan Natural Products via Phosphine-Palladium Catalysis
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Polyalkyl furans are widespread in nature, often performing important biological roles. Despite a plethora of methods for the synthesis of tetrasubstituted furans, the construction of tetraalkyl furans remains non-trivial. The prevalence of alkyl groups in bioactive furan natural products, combined with the desirable bioactivities of tetraalkyl furans, calls for a general synthetic protocol for polyalkyl furans. This paper describes a Michael–Heck approach, using sequential phosphine-palladium catalysis, for the preparation of various polyalkyl furans from readily available precursors. The versatility of this method is illustrated by the total syntheses of nine distinct polyalkylated furan natural products belonging to different classes, namely the furanoterpenes rosefuran, sesquirosefuran, and mikanifuran; the marine natural products plakorsins A, B, and D and plakorsin D methyl ester; and the furan fatty acids 3D5 and hydromumiamicin.
- Chen, Violet Yijang,Kwon, Ohyun
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supporting information
p. 8874 - 8881
(2021/03/17)
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- An Iron-Catalyzed Bond-Making/Bond-Breaking Cascade Merges Cycloisomerization and Cross-Coupling Chemistry
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Treatment of readily available enynes with alkyl-Grignard reagents in the presence of catalytic amounts of Fe(acac)3engenders a remarkably facile and efficient reaction cascade that results in the net formation of two new C?C bonds while a C?Z bond in the substrate backbone is broken. Not only does this new manifold lend itself to the extrusion of heteroelements (Z=O, NR), but it can even be used for the cleavage of activated C?C bonds. The reaction likely proceeds via metallacyclic intermediates, the iron center of which gains ate character before reductive elimination occurs. The overall transformation represents a previously unknown merger of cycloisomerization and cross-coupling chemistry. It provides ready access to highly functionalized 1,3-dienes comprising a stereodefined tetrasubstituted alkene unit, which are difficult to make by conventional means.
- Echeverria, Pierre -Georges,Fürstner, Alois
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supporting information
p. 11188 - 11192
(2016/10/13)
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- Total synthesis of the marine natural product (-)-clavosolide A
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The total synthesis of the marine metabolite clavosolide A is reported which confirms the structure and absolute configuration of the natural product as the symmetrical diolide glycosylated by permethylated D-xylose moieties, 2.
- Barry, Conor S.,Elsworth, Jon D.,Seden, Peter T.,Bushby, Nick,Harding, John R.,Alder, Roger W.,Willis, Christine L.
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p. 3319 - 3322
(2007/10/03)
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