- A Three-Phase Four-Component Coupling Reaction: Selective Synthesis of o-Chloro Benzoates by KCl, Arynes, CO2, and Chloroalkanes
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A transition-metal-free three-phase four-component coupling reaction (3P-4CR) involving KCl, arynes, chloroalkanes and CO2 has been reported for the first time, enabling the incorporation of both chloro and CO2 into an aryne simultaneously. The reactions for the synthesis of different types of o-chloro benzoates can be selectively modulated by the chloroalkane utilized. The corresponding products can be alternatively transformed for postsynthetic functionalizations conveniently.
- Jiang, Huanfeng,Zhang, Yu,Xiong, Wenfang,Cen, Jinghe,Wang, Lu,Cheng, Ruixiang,Qi, Chaorong,Wu, Wanqing
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supporting information
p. 345 - 349
(2019/01/24)
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- Regioselective reactions of highly substituted arynes
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"Chemical Equation Presented" The fully regioselective reactivity of four new highly substituted silyl aryl triflate aryne precursors in aryne acyl-alkylation, acyl-alkylation/ condensation, and heteroannulation reactions is reported. The application of these more complex arynes provides access to diverse natural product scaffolds and obviates late-stage functlonallzation of aromatic rings.
- Tadross, Pamela M.,Gilmore, Christopher D.,Bugga, Pradeep,Virgil, Scott C.,Stoltz, Brian M.
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supporting information; experimental part
p. 1224 - 1227
(2010/06/13)
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- An aryne route to cytosporone B and phomopsin C
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The octaketide cytosporone B has been synthesized in six steps using 1,3,5-trihydroxybenzene as a starting material via aryne insertion reaction into a carbon-carbon σ-bond.
- Yoshida, Hiroto,Morishita, Takami,Ohshita, Joji
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scheme or table
p. 508 - 509
(2010/08/22)
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- Enantioselective synthesis of a fluorinated analogue of the orsellinic acid-type twelve-membered lactone lasiodiplodin
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The chemoenzymatic synthesis of the racemate and the one enantiomer of the fluorinated analogue 8 of the natural cyclooxygenase inhibitor lasiodiplodin is decribed. A lipase-mediated deracemization of the fluorohydrin 18 provided the chiral, nonracemic building block for the enantioselective synthesis of the title compound. The key step was the formation of the 12-membered lactene by a ring-closing metathesis.
- Runge,Haufe
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p. 8737 - 8742
(2007/10/03)
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- Bromophloroglucinols and their methyl ethers
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All 16 bromination products of phloroglucinol and its methyl ethers, as well as five bromoresorcinols and three of their dimethyl ethers, were synthesized and analyzed by nuclear magnetic resonance spectroscopy.Two or three equivalents of bromine convert phloroglucinol to di- and tribromophloroglucinol, 5-methoxyresorcinol to the tri- and 2,4-dibromo, 3,5-dimethoxyphenol to the tri- and 2,6-dibromo, and 1,3,5-trimethoxybenzene to the dibromo compound.With one equivalent of bromine, 3,5-dimethoxyphenol reacts preferentially at C-2 while 5-methoxyresorcinol gives both monobromo isomers.Partial debromination with sodium sulfite yields successively 2,4-dibromo- and 2-bromo-5-methoxyresorcinol from the tribromo compound but fails with brominated 3,5-dimethoxyphenol.In the resorcinol series, C-2 is invariably the least reactive position. 4,6-Dibromo-5-methoxyresorcinol and 2,4-dibromo-3,5-dimethoxyphenol are accessible by methylation of dibromophloroglucinol, obtained from 3,5-dibromo-2,4,6-trihydroxybenzoic acid by decarboxylation.In contrast to resorcinol and tribromoresorcinol, the partial bromination of pholoroglucinol and debromination of tribromopholoroglucinol are not selective.The 13Cnmr spectra of bromophloroglucinol methyl ethers show characteristic downfield shifts for methoxy groups orthogonal to the aromatic ring plane.
- Kiehlmann, E.,Lauener, R. W.
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p. 335 - 344
(2007/10/02)
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