39491-61-7Relevant academic research and scientific papers
1,2- vs 1,4-Addition of acylbenzotriazoles to α,β-unsaturated aldehydes and ketones. A novel route to 3-alkyl-4,6-diaryl-3,4-dihydropyran-2-ones
Katritzky, Alan R.,Denisko, Olga V.
, p. 3104 - 3108 (2002)
Lithiation of aliphatic 1-acylbenzotriazoles with subsequent reaction with α,β-unsaturated ketones and aldehydes affords either 3,4,6-trisubstituted 3,4-dihydropyran-2-ones or 1,3-dienes depending on the carbonyl reagent used. Substituent effects on product yield and isomer ratio are discussed.
VINYL-COPPER DERIVATIVES XIII : SYNTHESIS OF CONJUGATED DIENES OF VERY HIGH STEREOISOMERIC PURITY
Jabri, N.,Alexakis, A.,Normant, J. F.
, p. 959 - 962 (1981)
Conjugated dienes are obtained by coupling of alkenyl cuprates and alkenyl halides in the presence of ZnBr2 and a catalytic amount of PdoL4.
Palladium-Catalyzed Regio- A nd Enantioselective Hydrosulfonylation of 1,3-Dienes with Sulfinic Acids: Scope, Mechanism, and Origin of Selectivity
Dong, Dongfang,Zhang, Qinglong,Zi, Weiwei
supporting information, p. 15860 - 15869 (2020/10/18)
Chiral sulfones are important structural motifs in organic synthesis because of their widespread use in pharmaceutical chemistry. In particular, chiral allylic sulfones have drawn particular interest because of their synthetic utility. However, enantioselective synthesis of 1,3-disubstituted unsymmetrical chiral allylic sulfones remains a challenge. In this article, we report a protocol for (R)-DTBM-Segphos/Pd-catalyzed regio- A nd enantioselective hydrosulfonylation of 1,3-dienes with sulfinic acids, which provides atom- A nd step-economical access to 1,3-disubstituted chiral allylic sulfones. The reaction occurs under mild conditions and has a broad substrate scope. Combined experimental and computational studies suggest that the reaction is initiated by a ligand-to-ligand hydrogen transfer followed by a C-S bond reductive elimination via a six-membered transition state. Steric repulsion between the olefinic C-H of the substrate and the tert-butyl group of (R)-DTBM-Segphos was found to be a key factor in the enantiocontrol.
Rhodium-catalyzed isomerization of unactivated alkynes to 1,3-dienes
Shintani, Ryo,Duan, Wei-Liang,Park, Soyoung,Hayashi, Tamio
, p. 3646 - 3647 (2008/09/20)
A rhodium/binap complex has been found to effectively catalyze the isomerization of unactivated internal alkynes to the corresponding 1,3-dienes in the presence of an azomethine imine as the reaction promoter. The Royal Society of Chemistry 2006.
Stereochemistry of direct olefin formation from carbonyl compounds and lithiated heterocyclic sulfones
Baudin, J. B.,Hareau, G.,Julia, S. A.,Lorne, R.,Ruel, O.
, p. 856 - 878 (2007/10/02)
The conditions for the title reaction were studied for the 2-benzothiazole and 2-pyridine series and for some examples in the 2-pyrimidine series.The olefin preparations were generally observed to be more efficient for 2-BT-sulfone systems.From the data of the hundred cases studied, it can be concluded that (E)-olefins are obtained: (i) from saturated BT-sulfones and aromatic aldehydes; and (ii) from benzylic BT-sulfones and branched saturated aldehydes (isobutyraldehyde, pivalaldehyde) or α,β-ethylenic or aromatic aldehydes. (Z)-olefins arise: (i) fom propargylic BT-sulfones and saturated or aromatic aldehydes; and (ii) from allylic or benzylic Pyr-sulfones and saturated aldehydes.Possible mechanisms for this new olefination procedure were examined. - heteroaromatic sulfones, organolithium derivatives, intramolecular ipso reactions, stereochemistry, elimination, olefination.
Alkenyl-copper derivatives 19. Synthesis of conjugated dienes and styrenes by cuopling of alkenyl cuprates with alkenyl and aryl halides
Jabri, N.,Alexakis, A.,Normant, J. F.
, p. 321 - 331 (2007/10/02)
Z dialkenylcuprates obtained by carbometallation of acetylene couple easily with alkenylhalides and iodoarenes in the presence of ZnBr2 and a catalytic amount of NiL4 or Pd0L4 to afford high yields of conjugated dienes and styrenes with very high stereoselectivity.Such pure dienes are often encountered in insect sex pheromones.
Additions of Carboxylic Acid Dianions to α,β-Unsaturated Carbonyl Compounds - Control of the 1,2-/1,4-Regioselectivity by Steric Substituent Effects
Mulzer, Johann,Bruentrup, Gisela,Hartz, Georg,Kuehl, Uwe,Blaschek, Ursula,Boehrer, Gerald
, p. 3701 - 3724 (2007/10/02)
Dilithium carboxylic acid dianions 1 attack α,β-unsaturated aldehydes (2) 1,2-regiospecifically with formation of the unsaturated β-hydroxy carboxylic acids 3/4.Additionally, the addition of the phenylacetate dianion 1a can be conducted to the threo-isomer with high selectivity by reversible reaction. - α,β-Enones (8) add 1 irreversibly in 1,2- and 1,4-position.Depending on the substitution pattern, the whole range from pure 1,2- to pure 1,4-adduct is covered.The influence of the 1-counterion M and of the solvent is significant; the 1,4-portion increases with the complexing effect of M and with the Lewis-basicity of the solvent.
