71155-81-2Relevant academic research and scientific papers
Tandem [2 + 2] cycloaddition-cycloreversion reactions in highly polar media: A convergent one-pot entry to substituted alkenes and dienes
Arrastia, Iosune,Cossio, Fernando P.
, p. 7143 - 7146 (1996)
Reaction at room temperature between acyl chlorides and aromatic or α,β-unsaturated aldehydes in the presence of a tertiary base and in 5M lithium perchlorate-diethyl ether (5M LPDE) as solvent yields substituted alkenes in satisfactory yields. The reaction is formally conceived as a [2 + 2] cycloaddition between the aldehyde and the in situ formed ketene, followed by thermal decarboxylation of the intermediate 2 oxetanone. Ketene itself yields α,β-unsaturated acids under these reaction conditions.
Solvate Ionic Liquids as Reaction Media for Electrocyclic Transformations
Eyckens, Daniel J.,Champion, Megan E.,Fox, Bronwyn L.,Yoganantharajah, Prusothman,Gibert, Yann,Welton, Tom,Henderson, Luke C.
, p. 913 - 917 (2016/03/01)
Solvate ionic liquids (SILs) consisting of lithium bis(trifluoromethylsulfonyl)imide dissolved in tri-or tetraglyme have recently emerged as a novel class of ionic liquids. Herein, the first use of solvate ionic liquids as a replacement for molecular solvents in electrocyclization reactions is reported. The SILs promoted both Diels-Alder and [2+2] cycloaddition reactions, compared to an appropriate molecular solvent, and 5 M lithium perchlorate in diethyl ether. The Gutmann acceptor number (AN) of these solvate ionic liquids has also been determined by 31P NMR spectroscopy to be 26.5, thus being modest Lewis acids.
Phosphine-catalyzed asymmetric synthesis of β-lactones from disubstituted ketenes and aldehydes
Chen, Shi,Mondal, Mukulesh,Ibrahim, Ahmad A.,Wheeler, Kraig A.,Kerrigan, Nessan J.
, p. 4920 - 4929 (2014/06/23)
In this article we describe a general catalytic procedure for the formation of β-lactones bearing two stereogenic centers, from disubstituted ketenes and achiral aldehydes. BINAPHANE was found to display excellent enantioselectivity (≤90% ee for eight examples) and good diastereoselectivity (≤90:10 for 13 examples) in catalyzing the formation of β-lactones bearing two stereogenic centers from achiral aldehydes (both aromatic and aliphatic) and alkylarylketenes or dialkylketenes. A preference for formation of the trans diastereomer was observed in these reactions. For those reactions where BINAPHANE failed as a catalyst, tri-n-butylphosphine was found to be an effective achiral nucleophilic catalyst, effecting good yield and diastereoselectivity in racemic β-lactone formation. Evidence for the involvement of phosphonium enolate intermediates in the reaction mechanism was obtained through reaction monitoring by 31P NMR spectroscopy and by comparison with previously characterized intermediates observed in the phosphine-catalyzed ketene homodimerization reaction.
