20038-12-4Relevant articles and documents
cis-dihydroxylation of unsaturated potassium alkyl- and aryltrifluoroborates
Molander, Gary A.,Figueroa, Ruth
, p. 75 - 78 (2006)
(Chemical Equation Presented) The cis-dihydroxylation of olefin-containing potassium alkyl- and aryltrifluoroborates proceeds readily in moderate to excellent yields. The resulting diols are efficient coupling partners in Suzuki-Miyaura-type reactions wit
Theoretical elucidation of kinetic and thermodynamic control of radical addition regioselectivity
Leach, Andrew G.,Wang, Renxiao,Erich Wohlhieter,Khan, Saeed I.,Jung, Michael E.,Houk
, p. 4271 - 4278 (2003)
The cyclizations of two structurally similar 2-oxo-5-hexenyl-type radicals have been investigated by ab initio and density functional (UB3LYP/6-31+G**//UHF/6-31G* and UB3LYP/6-31G*//UB3LYP/6-31G*) calculations. The origin of apparently contradictory reports of 6-endo and 5-exo cyclizations is determined. Kinetic control favors 6-endo cyclization, while thermodynamic control gives 5-exo cyclization, and the observation of different products from different research groups arises from the difference in experimental conditions used by the two groups. The outcome of a new cyclization reaction was predicted by using these theoretical techniques. Kinetic control is predicted to yield exclusively the products of 6-endo cyclization, while thermodynamic control would lead to an approximately equal mixture of one 6-endo and one 5-exo cyclized product. Experimental studies revealed that the reaction yields only the products of 6-endo cyclization through kinetic control.
Structure–activity relationship study of the anti-obesity natural product yoshinone A
Kawazoe, Yoshinori,Itakura, Yuki,Inuzuka, Toshiyasu,Omura, Sachikazu,Uemura, Daisuke
, p. 226 - 232 (2021/03/06)
Yoshinone A was derived from marine algae and shown to inhibit adipogenic differentiation. The natural compound is composed of a γ-pyrone ring and a side chain and that contains two asymmetric carbons. Although their absolute configuration has been determ
Cu-Catalyzed C-H Allylation of Benzimidazoles with Allenes
Dong, Yaxi,Breit, Bernhard
supporting information, p. 6765 - 6769 (2021/09/11)
CuH-catalyzed intramolecular cyclization and intermolecular allylation of benzimidazoles with allenes have been described. The reaction proceeded smoothly with the catalytic system of Cu(OAc)2/Xantphos and catalytic amount of (MeO)2MeSiH. This protocol features mild reaction conditions and a good tolerance of substrates bearing electron-withdrawing, electron-donating, or electron-neutral groups. A new catalytic mechanism was proposed for this copper hydride catalytic system.
Hydroalkylation of Olefins to Form Quaternary Carbons
Green, Samantha A.,Huffman, Tucker R.,McCourt, Ruairí O.,Van Der Puyl, Vincent,Shenvi, Ryan A.
supporting information, (2019/05/22)
Metal-hydride hydrogen atom transfer (MHAT) functionalizes alkenes with predictable branched (Markovnikov) selectivity. The breadth of these transformations has been confined to π-radical traps; no sp3 electrophiles have been reported. Here we describe a Mn/Ni dual catalytic system that hydroalkylates unactivated olefins with unactivated alkyl halides, yielding aliphatic quaternary carbons.
Hydroalkylation of Olefins to Form Quaternary Carbons
Green, Samantha A.,Huffman, Tucker R.,McCourt, Ruairí O.,Van Der Puyl, Vincent,Shenvi, Ryan A.
supporting information, p. 7709 - 7714 (2019/05/22)
Metal-hydride hydrogen atom transfer (MHAT) functionalizes alkenes with predictable branched (Markovnikov) selectivity. The breadth of these transformations has been confined to π-radical traps; no sp3 electrophiles have been reported. Here we describe a Mn/Ni dual catalytic system that hydroalkylates unactivated olefins with unactivated alkyl halides, yielding aliphatic quaternary carbons.
Lewis Acid Mediated Cyclizations: Diastereoselective Synthesis of Six- to Eight-Membered Substituted Cyclic Ethers
Ghosh, Arun K.,Tomaine, Anthony J.,Cantwell, Kelsey E.
supporting information, p. 4229 - 4246 (2017/09/12)
Cyclic ethers are widely abundant in natural products. Cyclic ether templates are also utilized in drug design and medicinal chemistry. Although the synthetic processes for this class of compounds have been studied extensively with respect to five- and six-membered rings, medium-sized cyclic ethers are synthetically more challenging due to a variety of factors. Herein, we report our results on the Lewis acid catalyzed synthesis of medium-sized cyclic ethers in a diastereoselective manner..
ARYLOXYACETYLINDOLES AND ANALOGS AS ANTIBIOTIC TOLERANCE INHIBITORS
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Paragraph 0499, (2016/08/10)
The disclosure provides compounds and pharmaceutical compositions of aryloxyacetylindoles compounds and analogs useful for treating chronic and acute bacterial infections. Certain of the compounds are compounds of general Formula (I) (I) or a pharmaceutically acceptable salt or prodrug thereof. Certain compounds of this disclosure are MvfR inhibitors. MvfR inhibitors reduce the formation of antibiotic tolerant bacterial strains and are useful for treating Gram-negative bacterial infections and reducing the virulence of Pseudomonas aeruginosa. Methods of treating bacterial infections in a subject, including Pseudomonas aeruginosa infections, are also provided by the disclosure.
Construction of enantioenriched cyclic compounds by asymmetric allylic alkylation and ring-closing metathesis
Giacomina, Francesca,Alexakis, Alexandre
supporting information, p. 6710 - 6721 (2013/11/06)
A new approach to highly enantioenriched cyclic compounds (up to 98a€‰% ee) has been developed by using ω-ethylenic allylic substrates in a one-pot asymmetric allylic alkylation and ring-closing metathesis sequence. The starting compounds are synthetic equivalents of cyclic allylic substrates. The method is exemplified with both Cu and Ir catalysts, and chiral phosphoramidite ligands. A new approach to highly enantioenriched cyclic compounds (up to 98a€‰% ee) has been developed by using ω-ethylenic allylic substrates in a one-pot asymmetric allylic alkylation and ring-closing metathesis sequence. The starting compounds are synthetic equivalents of cyclic allylic substrates. The method is exemplified with both Cu and Ir catalysts, and chiral phosphoramidite ligands. Copyright
Ring-closing metathesis of allylsilanes as a flexible strategy toward cyclic terpenes. Short syntheses of teucladiol, isoteucladiol, poitediol, and dactylol and an attempted synthesis of caryophyllene
Dowling, Matthew S.,Vanderwal, Christopher D.
scheme or table, p. 6908 - 6922 (2010/11/24)
The development of a strategy consisting of allylsilane ring-closing metathesis and subsequent SE′ electrophilic desilylation (allylsilane RCM/SE′) to construct exo-methylidenecycloalkanes is described. Its utility is documented in short syntheses of teucladiol and poitediol. A key transformation in the synthesis of teucladiol is an aldol addition that establishes three stereochemical relationships in one step with ≥10:1 diastereoselectivity and provides a fascinating example of double stereodifferentiation/kinetic resolution with racemic reaction partners in the context of natural product synthesis. The synthesis of (±)-teucladiol required five steps from cyclopentenone and proceeded in 28% overall yield; adaptation of this route to an enantioselective synthesis of (-)-teucladiol enabled the determination of the absolute configuration of this terpene natural product. The use of fluoride-mediated conditions in the final desilylation step preserves the location of the alkene, delivering the natural product (±)-isoteucladiol (five steps and 21% yield from cyclopentenone). The synthesis of poitediol showcases the power of RCM for constructing eight-membered rings and features a highly diastereoselective epoxidation/fluoride-mediated fragmentation sequence for installing the exo-methylidene group with an adjacent hydroxyl-bearing stereocenter. The synthesis of (±)-poitediol required seven steps and proceeded in 18% overall yield. Again, fluoride-mediated desilylation of a late-stage intermediate (with retention of double-bond location) delivered the natural product (±)-dactylol (seven steps and 24% yield). Efforts directed toward incorporating the RCM/SE′ sequence into a synthesis of caryophyllene are also disclosed. While ultimately unsuccessful, these efforts resulted in the identification of a novel metal alkylidene-promoted deallylation reaction of terminal 1,4-dienes. A possible mechanism for this unexpected deallylation reaction of 1,4-dienes is provided.
