691-83-8Relevant articles and documents
Leveraging the n→π* Interaction in Alkene Isomerization by Selective Energy Transfer Catalysis
Brüss, Linda,Daniliuc, Constantin G.,Gilmour, Ryan,McLaughlin, Calum,Molloy, John J.,Nevesely, Tomá?
supporting information, (2021/11/30)
Examples of geometric alkene isomerization in nature are often limited to the net exergonic direction (ΔG°0) comparatively under-represented. Inspired by the expansiveness of the maleate to fumarate (Z→E) isomerization in biochemistry, we investigated the inverse E→Z variant to validate nO→πC=O* interactions as a driving force for contra-thermodynamic isomerization. A general protocol involving selective energy transfer catalysis with inexpensive thioxanthone as a sensitizer (λmax=402 nm) is disclosed. Whilst in the enzymatic process nO→πC=O* interactions commonly manifest themselves in the substrate, these same interactions are shown to underpin directionality in the antipodal reaction by shortening the product alkene chromophore. The process was validated with diverse fumarate derivatives (>30 examples, up to Z:E>99:1), including the first examples of tetrasubstituted alkenes, and the involvement of nO→πC=O* interactions was confirmed by X-ray crystallography.
Steric effects on the stereochemistry of old yellow enzyme-mediated reductions of unsaturated diesters: Flipping of the substrate within the enzyme active site induced by structural modifications
Brenna, Elisabetta,Gatti, Francesco G.,Manfredi, Alessia,Monti, Daniela,Parmeggiani, Fabio
supporting information, p. 2859 - 2864 (2013/01/15)
The ene-reductase-mediated reduction of the carbon-carbon double bond of some alkyl 2- substituted butenedioates was investigated. The stereochemical outcome of the reaction was found to be influenced by steric effects. Ethyl and butyl citraconates were converted into the corresponding alkyl (R)-2-methylsuccinates with excellent enantioselectivity, whereas ethyl and butyl mesaconates were completely unreactive. Methyl 2-substituted fumarates were reduced to enantiomerically enriched methyl (S)-2-substituted succinates, whereas the (Z)-stereoisomers were left unreacted by enereductases. Labelling experiments were performed to investigate the mechanism of these bioreductions and explain their stereochemical outcome.
Acylphosphonates as Substrates for Wittig and Horner-Wittig Reactions. Unusual Stereoselectivity in the Synthesis of β-Phosphinoylacrylates
Harris, Roger L. N.,McFadden, Helen G.
, p. 417 - 424 (2007/10/02)
Phosphorus-stabilized carbanions with additional stabilizing groups react with dialkyl acylphosphonates (alkanoyl- and aroyl-phosphonates) to give fair to good yields of dialkyl vinylphoshponates, with some limitations imposed by competing side reactions
