16079-66-6Relevant academic research and scientific papers
A Convenient and Stereoselective Method for the Preparation of 2-Substituted 1,3-Alkadienes from 1,2-Disubstituted Cyclopropanols
Kozyrkov, Yurii Yu.,Kulinkovich, Oleg G.
, p. 344 - 346 (2004)
Sulfonates of cis-1,2-disubstituted cyclopropanols are converted into 2-substituted 1,3-alkadienes in moderate to good yields under the action of magnesium perchlorate and triethylamine in diethyl ether. High trans-stereoselectivity was observed for the preparation of the alkadienes with a 1,2-disubstituted double bond. The stereochemical outcome in the reaction is consistent with a concerted reaction mechanism involving an Mg(ClO 4)2-initiated cationic cyclopropyl-allyl isomerization of the cyclopropyl sulfonates which is accompanied by a deprotonation.
SYNTHESIS OF CONJUGATED DIENES BY NICKEL-CATALYZED REACTIONS OF 1,3-ALKADIEN-2-YL PHOSPHATES WITH GRIGNARD REAGENTS
Sahlberg, Christer,Quader, Abdul,Claesson, Alf
, p. 5137 - 5138 (1983)
2-Substitued 1,3-alkadienes were prepared in good yields by reactions of diethyl 1-methyl-2-propenyl phosphate and diethyl 1-methylene-3-phenyl-2-propenyl phosphate with various Grognard reagents in the presence of nickel(II) catalysts.
Crossed Regio- and Enantioselective Iron-Catalyzed [4+2]-Cycloadditions of Unactivated Dienes
Braconi, Elena,Cramer, Nicolai
, (2021/12/22)
The cyclohexene motif is ubiquitous in nature and specialty chemicals. A straightforward selective access to chiral cyclohexenes from unactivated dienes and dienophiles is not feasible by classical Diels–Alder reaction and constitutes an unsolved syntheti
A Dinickel Catalyzed Cyclopropanation without the Formation of a Metal Carbene Intermediate
Maity, Arnab K.,Kalb, Annah E.,Zeller, Matthias,Uyeda, Christopher
, p. 1897 - 1902 (2020/11/30)
(NDI)Ni2 catalysts (NDI=naphthyridine-diimine) promote cyclopropanation reactions of 1,3-dienes using (Me3Si)CHN2. Mechanistic studies reveal that a metal carbene intermediate is not part of the catalytic cycle. The (NDI)Ni2(CHSiMe3) complex was independently synthesized and found to be unreactive toward dienes. Based on DFT models, we propose an alternative mechanism that begins with a Ni2-mediated coupling of (Me3Si)CHN2 and the diene. N2 extrusion followed by radical C?C bond formation generates the cyclopropane product. This model reproduces the experimentally observed regioselectivity and diastereoselectivity of the reaction.
Zirconium-Mediated Cross-Coupling of Terminal Alkynes and Vinyl Bromides: Selective Synthesis of Cyclobutene and 1,3-Diene Derivatives
Barluenga, Jose,Rodriguez, Felix,Alvarez-Rodrigo, Lucia,Fananas, Francisco J.
, p. 101 - 108 (2007/10/03)
A diastereoselective synthesis of 1,3-butadiene or cyclobutene derivatives by a zirconium-mediated reaction of alkenyllithium compounds and vinyl bromides is reported. The key steps involve the generation of zirconocene-alkyne complexes from haloalkenes and subsequent coupling with alkenyl bromides. Thus, formally the process supposes the cross-coupling reaction between a terminal alkyne and an alkenyl bromide. Moreover, the use of butyl vinyl ether instead of vinyl bromide as the unsaturated system allows an alternative access to different 1,3-butadiene regioisomers.
Synthesis and transformations of metallocycles. 15. A novel method for β-vinylation of α-olefins with AlEt3 under the action of Ni- and Zr-containing catalysts
Ibragimov, A. G.,Zolotarev, A. P.,Muslukhov, R. R.,Lomakina, S. I.,Dzhemilev, U. M.
, p. 113 - 115 (2007/10/02)
A novel regioselective method has been developed for the synthesis of 2-substituted 1,3-butadienes by β-vinylation of α-olefins with AlEt3 in the presence of Ni- and Zr-containing catalysts. - Key words: dienes, synthesis; nickel complexes, catalysts; allyl compounds; organoaluminum compounds.
A General Method for the Synthesis of 2-Alkyl Substituted 1,3-Dienes Starting from 2-(Chloromethyl)-3-tosylpropene
Najera, Carmen,Sansano, Jose Miguel
, p. 5829 - 5844 (2007/10/02)
The alkylation of the monolithium derivative 5 of 2-(chloromethyl)-3-tosylpropene (1) with bromo- or iodo-methyltrimethylsilane affords the β-silyl sulfone 7, which after nucleophilic substitution of the chlorine atom followed by β-elimination of tosyltrimethylsilane, promoted by tetrabutylammonium fluoride (TBAF), gives 2-substituted conjugated dienes 6 and the outer-ring diene 14.Racemic ipsenol (10b), an aggregation pheromone of the bark beetle Ips paraconfusus Lanier, is prepared.
2-(Chloromethyl)-3-tosylpropene as useful reagent for the general synthesis of functionalized 2-substituted 1,3-dienes. Application to the synthesis of (±)-ipsenol
Najera,Sansano
, p. 3781 - 3784 (2007/10/02)
The reaction of the monolithium derivative of 2-(chloromethyl)-3-tosylpropene (2) with bromomethyltrimethylsilane affords the β-silyl sulfone 7, which after nucleophilic substitution followed by fluoride induced β-elimination of tosyltrimethylsilane gives 2-substituted conjugated dienes 1. When compound 7 reacts first with zinc in the presence of isovaleraldehyde and then with tetrabutylammonium fluoride racemic ipsenol (10), an aggregation pheromone of the bark beetle Ips paraconfusus Lanier, is prepared.
Silicon-Directed Diene Synthesis
Brown, Paul A.,Bonnert, Roger V.,Jenkins, Paul R.,Lawrence, Nicholas J.,Selim, Mohammed R.
, p. 1893 - 1900 (2007/10/02)
A synthesis of 2-substituted-1,3-dienes is reported which uses silicon as a control element: eight aldehydes were converted into α-silyl ketones by treatment with trimethylsilylmethylmagnesium chloride and rapid Collins oxidation.Addition of vinylmagnesiu
A SILICON DIRECTED DIENE SYNTHESIS
Brown, Paul A.,Bonnert, Roger V.,Jenkins, Paul R.,Selim, Mohammed R.
, p. 693 - 696 (2007/10/02)
A convenient method for the conversion of a series of aldehydes into substituted dienes is reported which uses silicon as a control element.
