70925-46-1Relevant academic research and scientific papers
Dehydrative Re2O7-Catalyzed Approach to Dihydropyran Synthesis
Lawrence, Jean-Marc I. A.,Floreancig, Paul E.
supporting information, p. 9513 - 9517 (2020/12/21)
Monoallylic 1,3- and 1,5-diols undergo Re2O7-mediated ionization to form allylic cations that engage in cyclization reactions to form dihydropyran products. The reactions give the 2,6-trans-stereoisomer as the major products as a result of minimizing steric interactions in a boat-like transition state. The results of these studies are consistent with cationic intermediates, with an intriguing observation of stereochemical retention in one example.
Stereodivergence in the Ireland-Claisen Rearrangement of α-Alkoxy Esters
Podunavac, Ma?a,Lacharity, Jacob J.,Jones, Kerry E.,Zakarian, Armen
supporting information, p. 4867 - 4870 (2018/08/24)
A systematic investigation into the Ireland-Claisen rearrangement of α-alkoxy esters is reported. In all cases, the use of KN(SiMe3)2 in toluene gave rearrangement products corresponding to a Z-enolate intermediate with excellent diastereoselectivity, presumably because of chelation control. On the other hand, chelation-controlled enolate formation could be overcome for most substrates through the use of lithium diisopropylamide (LDA) in tetrahydrofuran (THF).
Direct catalytic enantioselective vinylogous aldol reaction of α-branched enals with isatins
Cassani, Carlo,Melchiorre, Paolo
supporting information, p. 5590 - 5593 (2013/01/15)
The direct vinylogous aldol reaction of α-substituted α,β-unsaturated aldehydes with isatins is described. The chemistry provides easy access to valuable 3-substituted 3-hydroxyoxindole derivatives with high stereocontrol and perfect γ-site selectivity. P
Catalytic asymmetric epoxidation of α-branched enals
Lifchits, Olga,Reisinger, Corinna M.,List, Benjamin
supporting information; experimental part, p. 10227 - 10229 (2010/09/06)
An asymmetric catalytic epoxidation of α-branched, α,β-unsaturated aldehydes is presented. A highly synergistic combination of a primary cinchona-based amine and a chiral phosphoric acid was found to promote the reaction with excellent enantiocontrol for α-monosubstituted and α,β-disubstituted enals.
Cooperative organocatalysis for the asymmetric γ alkylation of α-branched enals
Bergonzini, Giulia,Vera, Silvia,Melchiorre, Paolo
supporting information; experimental part, p. 9685 - 9688 (2011/03/16)
α Branched leads to γ: The direct and enantioselective γ alkylation of α-substituted α,β-unsaturated aldehydes under dienamine catalysis has been achieved. A cooperative catalysis system that involves dienamine activation of α-branched enals and chiral Bronsted acid catalysis promotes an SN1-alkylation pathway while ensuring complete γ-site selectivity and high stereocontrol (see scheme; Bn=benzyl). Copyright
Stereocontrolled one-pot synthesis of cycloalkane derivatives possessing a quaternary carbon using allyl phenyl sulfone
Ota, Koichiro,Kurokawa, Takao,Kawashima, Etsuko,Miyaoka, Hiroaki
experimental part, p. 8668 - 8676 (2010/01/06)
Stereocontrolled one-pot synthesis of cyclopentane derivatives possessing quaternary carbon using allyl phenyl sulfone and epoxyiodide was presented. Furthermore, application of this protocol to the synthesis of cycloalkane derivatives with different ring
Tandem-directed regioselective hydroformylation/β-elimination: A practical method for the synthesis of enals
Bruch, Achim,Gebert, Antje,Breit, Bernhard
experimental part, p. 2169 - 2176 (2009/04/10)
A practical synthesis of α,β-unsaturated aldehydes by a tandem-directed hydroformylation/β-elimination process of allylic o-DPPB esters is reported. The o-DPPB group served as an effective controller for regioselectivity of the hydroformylation towards th
Stereoselective alkylation of α,β-unsaturated imines via C-H bond activation
Colby, Denise A.,Bergman, Robert G.,Ellman, Jonathan A.
, p. 5604 - 5605 (2007/10/03)
The stereoselective alkylation of α,β-unsaturated imines via C-H activation followed by imine hydrolysis produces tri- and tetrasubstituted α,β-unsaturated aldehydes. In the presence of a rhodium catalyst, α,β-unsaturated N-benzyl imines derived from meth
Unusual gold(I)-catalyzed isomerization of 3-hydroxylated 1,5-enynes: Highly substrate-dependent reaction manifolds
Gagosz, Fabien
, p. 4129 - 4132 (2007/10/03)
(Chemical Equation Presented) The gold(I) isomerization of diversely substituted 3-hydroxylated enynes has led to the discovery of three new unreported skeletal rearrangements furnishing structures such as alkylidene-cyclopentenes, cyclohexadienes or α,β-
Efficient construction of benzohydrindenones from aryltrienones via domino Nazarov electrocyclization - Electrophilic aromatic substitution
Browder, Cindy C.,Marmsaeter, Fredrik P.,West
, p. 375 - 385 (2007/10/03)
1,4-Dien-3-ones substituted with pendant arylethyl side chains attached at C-1 were readily prepared from substituted dihydrocinnamaldehydes. Treatment with TiCl4 at low temperature effected domino Nazarov electrocyclization - arene trapping within 5 min to give racemic benzohydrindenones in near-quantitative yield and with complete diastereoselectivity.
