75567-08-7Relevant academic research and scientific papers
Cobalt-Catalyzed Diastereo- And Enantioselective Reductive Allyl Additions to Aldehydes with Allylic Alcohol Derivatives via Allyl Radical Intermediates
Wang, Lei,Wang, Lifan,Li, Mingxia,Chong, Qinglei,Meng, Fanke
supporting information, p. 12755 - 12765 (2021/08/30)
Catalytic generation of ambiphilic π-allyl-metal complexes and their utility in enantioselective transformations constitutes a powerful approach for introduction of allyl groups to a molecule. Herein an unprecedented cobalt-catalyzed highly site-, diastereo-, and enantioselective protocol for stereoselective formation of nucleophilic allyl-Co(II) complexes followed by addition to aldehydes is presented. The reaction features diastereo- and enantioconvergent conversion of easily accessible allylic alcohol derivatives to diversified enantioenriched homoallylic alcohols with a remarkably broad scope of allyl groups that can be introduced. Mechanistic studies indicated that allyl radical intermediates were involved in this process. These new discoveries establish a new strategy for development of enantioselective transformations through capture of radicals by chiral Co complexes, pushing forward the frontier of Co complexes for enantioselective catalysis.
SN2″-Selective and Enantioselective Substitution with Unsaturated Organoboron Compounds and Catalyzed by a Sulfonate-Containing NHC-Cu Complex
Zhou, Yuebiao,Shi, Ying,Torker, Sebastian,Hoveyda, Amir H.
supporting information, p. 16842 - 16854 (2018/11/27)
The first broadly applicable strategy for SN2″-selective and enantioselective catalytic substitution is disclosed. Transformations are promoted by 5.0 mol% of a sulfonate-containing NHC-Cu complex (NHC = N-heterocyclic carbene), and are carried
Chiral gold complex-catalyzed hetero-diels-alder reaction of diazenes: Highly enantioselective and general for dienes
Liu, Bin,Li, Kang-Nan,Luo, Shi-Wei,Huang, Jian-Zhou,Pang, Huan,Gong, Liu-Zhu
supporting information, p. 3323 - 3326 (2013/04/23)
A chiral gold(I) complex-catalyzed highly regio- and enantioselective azo hetero-Diels-Alder reaction has been developed. The chiral gold(I) complex acting as a Lewis acid exhibits high efficiency in the activation of urea-based diazene dienophiles. Moreover, this chiral gold catalyst also rendered a cascade intramolecular enyne cycloisomerization/asymmetric azo-HDA reaction.
Isomerization of electron-poor alkynes to the corresponding (E, E)-1,3-dienes using a bifunctional polymeric catalyst bearing triphenylphosphine and phenol groups
Kwong, Cathy Kar-Wing,Fu, Michael Yunyi,Law, Henry Chun-Hin,Toy, Patrick H.
supporting information; experimental part, p. 2617 - 2620 (2010/11/24)
The use of a bifunctional non-cross-linked polystyrene bearing both phosphine and phenol groups for the organocatalytic isomerization of alkynes bearing electron-withdrawing ester substituents to afford the corresponding (E,E)-dienes in excellent yield an
Tandem Michael - Wittig - Horner reaction: One-pot synthesis of δ- substituted α,β-unsaturated carboxylic acid derivatives - application to a concise synthesis of (Z)- and (E)-ochtoden-1-al
Piva, Olivier,Comesse, Sebastien
, p. 2417 - 2424 (2010/12/01)
A new tandem Michael-Wittig-Horner reaction has been developed to produce in high yields δ-substituted α,β-unsaturated esters, amides and lactones. The reaction has been successfully applied to a concise synthesis of (E)- and (Z)-ochtoden-1-als, component
SYNTHESIS OF (E)-VINYLIC TELLURIDES AND THEIR TRANSFORMATION INTO α,β-UNSATURATED ESTERS AND CARBOXYLIC ACIDS
Dabdoub, Miguel J.,Begnini, Mauro L.,Cassol, Tania M.,Guerrero, Palimecio G.,Silveira, Claudio C.
, p. 7623 - 7626 (2007/10/02)
Zirconium alkenyls and dienyls of E configuration, obtained by the hydrozirconation of alkynes or conjugated enynes containing a terminal triple bond undergo the Zr/Te exchange reaction by treatment with C4H9TeBr or C4H9TeI in THF at -78 deg C.The Zr/Te exchange reaction proceeds with total retention of configuration and with complete stereoselectivity at the carbon 1, furnishing (E)-butyltelluro alkenes (64-86percent yields) and (E)-1-butyltelluro-1,3-dienes (68-75percent yields).Vinylic tellurides were transformed into α,β-unsaturated esters and carboxylic acids with total retention of the regio- and stereochemistry via vinyl lithium intermediates.
A Novel and Stereodefined Synthesis of (E)-β-Ethoxycarbonylvinylsilanes: Regio- and Stereo-controlled Hydroethoxycarbonylation of Silylacetylenes by Palladium(II) Catalysis
Takeuchi, Ryo,Sugiura, Masaharu
, p. 1031 - 1038 (2007/10/02)
-SnCl2*2H2O catalysed hydroethoxycarbonylation of silylacetylenes 1 provided a novel and convenient synthesis of (E)-β-ethoxycarbonylvinylsilanes 2.The reactions, carried out under mild conditions (90 deg C, 20 kg cm-2) gave the pr
Conversion of 2-Sulfinylated 2-Alkenoate Esters to (2E,4E)-2,4-Alkadienoate Esters by Pyrolysis
Tanikaga, Rikuhei,Nozaki, Yoshihito,Nishida, Masaharu,Kaji, Aritsune
, p. 729 - 733 (2007/10/02)
Thermal reaction of ethyl (2E)-2-phenylsulfinyl-2-alkenoates (E-2) prepared from aldehydes and ethyl 2-phenylsulfinylacetate have been investigated.Refluxing of E-2 or their Z-isomers in xylene resulted in the formation of ethyl (2E,4E)-2,4-alkanedioates accompanied by ethyl (2E)-4-hydroxy-2-alkenoates.Ethyl 2-cycloalkylidene-2-phenylsulfinylacetates were found to be more susceptible to pyrolysis.The enoate esters (2) undergo migration of their carbon-carbon double bond and then sigmatropic rearrangement to benzenesulfenate esters, followed by thermolytic extrusion of a benzenesulfenic acid probably via ethyl(2E)-4-phenylsulfinyl-2-alkenoates to afford ethyl (2E,4E)-2,4-alkadienoates.
Synthesis of Hydroxy-γ-lactones from α,β-Unsaturated Aldehydes
Marschall, Helga,Penninger, Josef,Weyerstahl, Peter
, p. 49 - 67 (2007/10/02)
According to Scheme 1 the α,β-unsaturated aldehydes 3-9 react in three steps (epoxidation, PO olefination, and selective hydrogenation) to give the epoxy esters 36-42.Generally, these steps are interchangeable, predominantly the epoxidation and olefination.Thus, the epoxy acid esters 26-32 are synthesized via the epoxides 10-16 or via the dienoic esters 17-23.Homogeneously catalyzed hydrogenation of 26-31 gives the saturated esters 36-41.In case this reaction fails (e.g. with 32), sequence e, g (Scheme 1) via γ,δ-unsaturated esters (e.g. 35) might be successful.All these α,β-unsaturated esters 17-23 and 26-32 possess (E) configuration.Even the reaction of 3 or 6 with the propionate 2 leads to the (E) esters 24 or 25, respectively.Hydrolysis of the epoxy acid esters 36-41 gives the hydroxy-γ-lactones 43-48.
THE SIMPLE SYNTHESIS OF ETHYL 2,4-DIENOATES FROM ALDEHYDES AND ETHYL 2-PHENYLSULFINYLACETATE
Tanikaga, Rikuhei,Nishida, Masaharu,Ono, Noboru,Kaji, Aritsune
, p. 781 - 782 (2007/10/02)
Treatment of aldehydes and ethyl 2-phenylsulfinylacetate (1) in the presence of piperidine gives Z-isomers (Z-2) of phenylsulfinyl-2-alkylideneacetates (2).Thermolysis of Z-2 results in the formation of ethyl E,E-2,4-dienoates (3).
