- Synthesis of (Z)-alkene-containing linear conjugated dienyl homoallylic alcohols by a palladium-catalyzed three-component reaction
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A synthesis of (Z)-alkene-containing linear conjugated dienyl homoallylic alcohols by using a palladium-catalyzed three-component reaction has been developed. This method shows good functional-group compatibility and generality, with high diastereoselectivity. Additionally, in many cases, the present method controls the alkene stereochemistry of the newly formed C-C bond and overcomes the inherent preference for (E)-alkene formation, giving (Z, E)- and (Z, Z)-products.
- Horino, Yoshikazu,Sakamoto, Juri,Murakami, Miki,Sugata, Miki
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supporting information
p. 1323 - 1327
(2020/08/21)
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- Gold-Catalyzed Iminations of Terminal Propargyl Alcohols with Anthranils with Atypical Chemoselectivity for C(1)-Additions and 1,2-Carbon Migration
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This work reports gold-catalyzed iminations of terminal propargyl alcohols with anthranils or isoxazoles to yield E-configured α-amino-2-en-1-ones and -1-als with complete chemoselectivity. These catalytic iminations occur exclusively with C(1)-nucleophilic additions on terminal alkynes, in contrast to a typical C(2)-route. For 3,3-dialkylprop-1-yn-3-ols, a methyl substituent is superior to long alkyl chains as the 1,2-migration groups toward α-imino gold carbenes. For secondary prop-1-yn-3-ols, phenyl, vinyl, and cyclopropyl substituents are better than hydrogen as the migrating groups, obviating typical gold carbene reactions. DFT calculations have been performed to rationalize the observed C(1)-regioselectivity and the preferable cyclopropyl migration based on gold carbene pathways.
- Skaria, Manisha,More, Sayaji Arjun,Kuo, Tung-Chun,Cheng, Mu-Jeng,Liu, Rai-Shung
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p. 3600 - 3608
(2020/03/04)
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- Allenylic Carbonates in Enantioselective Iridium-Catalyzed Alkylations
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An enantioconvergent C(sp3)-C(sp3) coupling between racemic allenylic electrophiles and alkylzinc reagents has been developed. An Ir/(phosphoramidite,olefin) catalyst provides access to highly enantioenriched allenylic substitution p
- Petrone, David A.,Isomura, Mayuko,Franzoni, Ivan,R?ssler, Simon L.,Carreira, Erick M.
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supporting information
p. 4697 - 4704
(2018/04/11)
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- Enantioselective Propargylation of Polyols and Desymmetrization of meso 1,2-Diols by Copper/Borinic Acid Dual Catalysis
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A copper/borinic acid dual catalytic reaction enabled the enantioselective propargylation of aliphatic polyols. Readily available reagents and catalysts were used in this transformation, which displayed good to excellent chemo- and stereoselectivity for a broad array of substrates. The method was also applicable to the desymmetrization of meso 1,2-diols to furnish products with three stereogenic centers and a terminal alkyne group in one operation.
- Li, Ren-Zhe,Tang, Hua,Yang, Ke R.,Wan, Li-Qiang,Zhang, Xia,Liu, Jie,Fu, Zhengyan,Niu, Dawen
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supporting information
p. 7213 - 7217
(2017/06/13)
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- One-Pot Cannizzaro Cascade Synthesis of ortho-Fused Cycloocta-2,5-dien-1-ones from 2-Bromo(hetero)aryl Aldehydes
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An intramolecular Cannizzaro-type hydride transfer to an in situ prepared allene enables the synthesis of ortho-fused 4-substituted cycloocta-2,5-dien-1-ones with unprecedented technical ease for an eight-ring carboannulation. Various derivatives could be obtained from commercially available (hetero)aryl aldehydes, trimethylsilylacetylene, and simple propargyl chlorides in good yields. A cascade process that is triggered by an intramolecular Cannizzaro-type hydride transfer to an in situ prepared allene leads to the formation of 4-substituted cycloocta-2,5-dien-1-ones. Various derivatives could be obtained from commercially available (hetero)aryl aldehydes, trimethylsilylacetylene, and simple propargyl chlorides in good yields.
- Burroughs, Laurence,Eccleshare, Lee,Ritchie, John,Kulkarni, Omkar,Lygo, Barry,Woodward, Simon,Lewis, William
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supporting information
p. 10648 - 10651
(2015/09/02)
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- Gold-catalyzed reactions of propargylic esters with vinylazides for the synthesis of Z- or E-configured buta-1,3-dien-2-yl esters
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Gold-catalyzed synthesis of buta-1,3-dien-2-yl esters by the reaction of propargyl esters with vinylazides is described; the reaction mechanism is postulated to involve a vinyl attack of vinylazides at alkenyl gold carbenes.
- Wagh, Sachin Bhausaheb,Liu, Rai-Shung
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supporting information
p. 15462 - 15464
(2015/10/20)
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- Coupling-isomerization synthesis of chalcones
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The Sonogashira coupling of electron-deficient (hetero)aryl halides 1 and (hetero)aryl or alkenyl 1-propargyl alcohols 2 does not terminate at the stage of the expected internal propargyl alcohols, but rather gives rise to the formation of α,β-unsaturated ketones 3 with a variety of acceptor substituents. This new domino reaction, a coupling-isomerization reaction (CIR), can be rationalized as a sequence of rapid Pd/Cu-catalyzed alkynylation followed by a slow amine-base-catalyzed propargyl alcohol-enone isomerization. Performing the CIR in deuterated protic solvents or with a selectively deuterated propargyl alcohol revealed that the base-catalyzed isomerization step proceeds through a formal 1,3-H shift with minimal H/D exchange with the surrounding solvent. Additionally, 19F NMR kinetic measurements on the isomerization step with the fluorinated propargyl alcohol 4r support the mechanistic rationale.
- Braun, Roland U.,Ansorge, Markus,Mueller, Thomas J. J.
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p. 9081 - 9094
(2007/10/03)
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- 4- AND 5-ALKYNYLOXINDOLES AND 4- AND 5-ALKENYLOXINDOLES
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4- and 5-alkynyloxindoles as well as 4- and 5-alkenyloxindoles having formula (I) and (II), wherein R, R, R, R, R, X and z have the meaning indicated in the specification, inhibit or modulate protein kinases, in particular JNK protein kinases and are useful as anti-inflammatory agents, particularly in the treatment of rheumatoid arthritis.
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Page/Page column 28
(2010/02/04)
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- Pyrethroid esters
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A compound in all possible stereoisomeric forms and mixtures thereof of the formula STR1 wherein the substituents are defined as in the specification having pesticidal properties.
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