- Total Synthesis of (+)-Cornexistin
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Herein, we describe the first total synthesis of (+)-cornexistin as well as its 8-epi-isomer starting from malic acid. The robust and scalable route features a Nozaki–Hiyama–Kishi reaction, an auxiliary-controlled syn-Evans-aldol reaction, and a highly efficient intramolecular alkylation to form the nine-membered carbocycle. The delicate maleic anhydride moiety of the nonadride skeleton was constructed from a β-keto nitrile. The developed route enabled the synthesis of 165 mg (+)-cornexistin.
- Barber, David M.,Magauer, Thomas,Steinborn, Christian,Wildermuth, Raphael E.
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supporting information
p. 17282 - 17285
(2020/08/21)
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- Diastereoselective Synthesis of Highly Substituted Tetrahydrofurans by Pd-Catalyzed Tandem Oxidative Cyclization-Redox Relay Reactions Controlled by Intramolecular Hydrogen Bonding
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Palladium-catalyzed oxidative cyclization of alkenols provides a convenient entry into cyclic ethers but typically proceeds with little or no diastereoselectivity for cyclization of trisubstituted olefins to form tetrahydrofurans due to the similar energi
- Brooks, Joshua L.,Xu, Liping,Wiest, Olaf,Tan, Derek S.
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supporting information
p. 57 - 75
(2017/04/26)
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- Copper-Catalyzed Oxyboration of Unactivated Alkenes
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The first regiodivergent oxyboration of unactivated terminal alkenes is reported, using copper alkoxide as a catalyst, bis(pinacolato)diboron [(Bpin)2] as a boron source, and (2,2,6,6-tetramethylpiperidin-1-yl)oxyl (TEMPO) as an oxygen source. The reaction is compatible with various functional groups. Two regioisomers are selectively produced by selecting the appropriate ligands on copper. The products may be used as a linchpin precursor for various other functionalizations, and net processes such as carbooxygenation, aminooxygenation, and dioxygenation of alkenes can be achieved after C-B bond transformations. Mechanistic studies indicate that the reaction involves the following steps: 1)Transmetalation between CuOtBu and (Bpin)2 to generate a borylcopper species; 2)regiodivergent borylcupration of alkenes; 3) oxidation of the thus-generated C-Cu bond to give an alkyl radical; 4)trapping of the resulting alkyl radical by TEMPO.
- Itoh, Taisuke,Matsueda, Takumi,Shimizu, Yohei,Kanai, Motomu
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p. 15955 - 15959
(2015/11/03)
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- Stereoselective synthesis of conjugated trienols from allylic alcohols and 1-iodo-1,3-dienes
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The stereoselective synthesis of conjugated trienes has been achieved from allylic alcohols and 1-iodo-1,3-dienes using Pd(OAc)2/AgOAc.
- Brandt, Damien,Bellosta, Veronique,Cossy, Janine
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supporting information
p. 5594 - 5597,4
(2012/12/12)
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- Lewis acid-promoted addition of 1,3-bis(silyl)propenes to aldehydes: A route to 1,3-dienes
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The Lewis acid-promoted addition of 1,3-bis(silyl)-propenes to aldehydes to provide the corresponding (E)-1,3-dienes in excellent stereoselectivity and good to excellent yields is reported. The procedure is mild, base-free, and operationally straightforward.
- Borg, Tessie,Tuzina, Pavel,Somfai, Peter
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experimental part
p. 8070 - 8075
(2011/11/28)
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- Total synthesis of (-)-exiguolide
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The first total synthesis of the naturally occurring enantiomer of exiguolide ((-)-1) has been completed. This very convergent synthesis features the following as main steps: (I) a Trost's ruthenium-catalyzed ene-yne cross-coupling reaction (this complex transformation allows the challenging control of the C5-C28 double bond geometry along with the stereoselective construction of the tetrahydropyran ring A) and (II) a very efficient one-pot, two-step stereoselective conjugated allyllc alcohol substitution that allowed the control of the C15 stereogenic center.
- Cook, Cyril,Guinchara, Xavier,Liron, Frederic,Roulland, Emmanuel
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supporting information; experimental part
p. 744 - 747
(2011/03/17)
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- Synthesis of complex allylic esters via C-H oxidation vs C-C Bond formation
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A highly general, predictably selective C-H oxidation method for the direct, catalytic synthesis of complex allylic esters is introduced. This Pd(II)/sulfoxide-catalyzed method allows a wide range of complex aryl and alkyl carboxylic acids to couple directly with terminal olefins to furnish (E)-allylic esters in synthetically useful yields and selectivities (16 examples, E/Z ≤ 10:1) and without the use of stoichiometric coupling reagents or unstable intermediates. Strategic advantages of constructing allylic esters via C-H oxidation vs C-C bond-forming methods are evaluated and discussed in four case studies.
- Vermeulen, Nicolaas A.,Delcamp, Jared H.,White, M. Christina
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supporting information; scheme or table
p. 11323 - 11328
(2010/10/04)
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- Copper-catalyzed asymmetric allylic alkylation of halocrotonates: Efficient synthesis of versatile chiral multifunctional building blocks
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The highly enantioselective synthesis of amethyl-substituted esters is reported in up to 90% yield and up to 99% ee using copper-TaniaPhos as chiral catalyst. The transformation proved scalable to at least 6.6 mmol (1.7 g scale). The products of this transformation have been further elaborated to multifunctional building blocks with a single (branched esters and acids) or multiple stereogenic centers (vicinal dimethyl esters, as well as, hydroxy- or iodosubstituted lactones).
- Den Hartog, Tim,Macia, Beatriz,Minnaard, Adriaan J.,Feringa, Ben L.
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experimental part
p. 999 - 1013
(2010/08/07)
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- Total synthesis of (-)-spongidepsin
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A convergent and rapid stereoselective synthesis of (-)-spongidepsin has been achieved from the Roche ester in 14 steps with an overall yield of 13%.
- Ferrie, Laurent,Reymond, Sebastien,Capdevielle, Patrice,Cossy, Janine
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p. 3441 - 3443
(2007/10/03)
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- Novel oxepane formation by TiCl4-catalyzed nucleophilic cleavage of 1- alkoxymethyl-6,8-dioxabicyclo[3.2.1]octanes
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Introduction of an alkoxymethyl group at the C1 position in the 6,8- dioxabicyclo[3.2.1]octane system enabled novel formation of oxepane compounds in TiCl-4-catalyzed acetal cleavage reactions. (C) 2000 Elsevier Science Ltd.
- Fujiwara, Kenshu,Amano, Arika,Tokiwano, Tetsuo,Murai, Akio
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p. 1065 - 1080
(2007/10/03)
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- A simple method for the conversion of primary alcohols into terminal olefins
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Treatment of benzyl ethers of primary alcohols with n-butyllithium (n-BuLi) afforded terminal olefins in good yield.
- Matsushita, Masayuki,Nagaoka, Yoko,Hioki, Hideaki,Fukuyama, Yoshiyasu,Kodama, Mitsuaki
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p. 1039 - 1040
(2007/10/03)
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- The mechanisms of n-butyllithium induced β-cleavage of 2-methyltetrahydrofuran and oxepane
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The n-butyllithium induced β-cleavage reactions of 2-methyltetrahydrofuran and oxepane operate via different mechanisms. 2-Methyltetrahydrofuran undergoes an E2 elimination, whilst oxepane undergoes an α,β′-elimination involving initial deprotonation at the α-position followed by a transannular hydrogen transfer.
- Cohen, Theodore,Stokes, Stephen
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p. 8023 - 8024
(2007/10/02)
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