120113-92-0Relevant articles and documents
A FACILE SYNTHESIS OF γ,δ-UNSATURATED ESTERS BY THE Pd(II) CATALYZED CLAISEN REARRANGEMENT
Ohshima, Masahiro,Murakami, Masahiro,Mukaiyama, Teruaki
, p. 1535 - 1536 (1984)
A mixed ortho ester is prepared under mild conditions from an allyl alcohol and a ketene acetal in the presence of PdCl2(COD).The ortho ester thus formed is successively treated with a catalytic amount of PdCl2(PPh3)2 in refluxing p-xylene to afford a γ,δ-unsaturated ester in a high yield under neutral conditions.
Highly Regio- A nd Enantioselective Hydrogenation of Conjugated α-Substituted Dienoic Acids
Liu, Xian,Liu, Song,Wang, Quanjun,Zhou, Gang,Yao, Lin,Ouyang, Qin,Jiang, Ru,Lan, Yu,Chen, Weiping
, p. 3149 - 3154 (2020/04/09)
Highly regio- A nd enantioselective hydrogenation of conjugated α-substituted dienoic acids was realized for the first time using Trifer-Rh complex, providing a straightforward method for the synthesis of chiral α-substituted ?,?′-unsaturated acids. DFT calculations revealed N+H-O hydrogen bonding interaction is formed to stabilize the transition state and the coordination of 4,5-double bond to Rh(III) center would facilitate the reductive elimination process. This hydrogenation provided a gram-scale synthesis of the precursor of sacubitril.
Synthesis of α-(Pentafluorosulfanyl)- and α-(Trifluoromethyl)-Substituted Carboxylic Acid Derivatives by Ireland-Claisen Rearrangement
Dreier, Anna-Lena,Beutel, Bernd,Mück-Lichtenfeld, Christian,Matsnev, Andrej V.,Thrasher, Joseph S.,Haufe, Günter
, p. 1638 - 1648 (2017/02/10)
Earlier studies have shown that [3,3]-sigmatropic rearrangements of allyl esters are useful for the construction of fluorine-containing carboxylic acid derivatives. This paper describes the synthesis of 3-aryl-pent-4-enoic acid derivatives bearing either a pentafluorosulfanyl (SF5) or a trifluoromethyl (CF3) substituent in the 2-position by treatment of corresponding SF5- or CF3-acetates of p-substituted cinnamyl alcohols with triethylamine followed by trimethylsilyl triflate (TMSOTf). This Ireland-Claisen rearrangement delivered approximate 1:1 mixtures of syn/anti diastereoisomers due to tiny differences (3N) led to oligomerization of the cinnamyl SF5- and CF3-acetates. Treatment of the corresponding regioisomeric 1-phenyl-prop-2-en-1-yl acetates under the latter conditions resulted in [1,3]-sigmatropic rearrangement and subsequent oligomerization of the intermediately formed cinnamyl esters. When Et3N was added first followed by TMSOTf, no further reaction of the formed ester was detected.
The Regio- and Stereoselectivities of the Reaction of Allyl Acetates and Silyl Ketene Acetals Catalyzed by Pd(0) Complexes: A New Route to Cyclopropane Derivatives
Carfagna, C.,Mariani, L.,Musco, A.,Sallese, G.,Santi, R.
, p. 3924 - 3927 (2007/10/02)
Pd(0) complexes of chelating phosphines catalyzed the coupling of allyl acetates and ketene silyl acetals to yield α-allylated carboxylic acid esters.Unexpectedly alkylation of the central carbon atom (C2) of the allyl groups was also observed with concomitant formation of cyclopropane derivatives.In both cases the silyl enolate attacked the allyl group from the side opposite Pd.The yield of the reaction was sensitive to the nature of the ligand coordinated with palladium.The 1,1'-bis(diphenylphosphino)ferrocene-Pd complex was the most effective catalyst.
Cobalt-Mediated Intermolecular Radical Additions to Carbon-to-Carbon Double Bonds leading to New Functionalised Alkenes
Bhandal, Harcharan,Howell, Amy R.,Patel, Vinod F.,Pattenden, Gerald
, p. 2709 - 2714 (2007/10/02)
Alkyl radicals generated by photolytic homolysis of cobalt salophen reagents, e.g. (6) and (15), are shown to add to activated carbon-to-carbon double bonds, i.e. ethyl acrylate, methyl vinyl ketone, acrylonitrile, and styrene, producing preparatively useful yields of new alkene products, viz. (9), (10), (12) and (14) , and (16) .The reactions proceed via radical (Michael) additions, followed by 'dehydrocobaltation' from the presumed organocobalt intermediates (2) (Scheme 4).By use of this chemistry, in combination with the Schrauzer 'hydrocobaltation' reaction of alkenes, a new method for the cross-coupling reactions between two alkenes, leading to new functionalised alkenes, e.g. (24), (25), (26), (27), (28), and (29), is developed .
Hydrocobaltation-Dehydrocobaltation Reactions in Synthesis: A New Approach to the Controlled Cross-Coupling between sp2 Carbon Centres leading to Functionalised Alkenes
Bhandal, Harcharan,Pattenden, Gerald
, p. 1110 - 1112 (2007/10/02)
Cross-coupling reactions between two alkenes, leading to new functionalised alkenes, can be brought about via 'hydrocobaltation' of one of the alkenes followed by irradiation of the resulting organocobalt reagent in the presence of the second alkene subst
