1040880-61-2Relevant academic research and scientific papers
A Bio-Inspired, Catalytic e → Z Isomerization of Activated Olefins
Metternich, Jan B.,Gilmour, Ryan
supporting information, p. 11254 - 11257 (2015/09/21)
Herein, Natures flavin-mediated activation of complex (poly)enes has been translated to a small molecule paradigm culminating in a highly (Z)-selective, catalytic isomerization of activated olefins using (-)-riboflavin (up to 99:1 Z/E). In contrast to the prominent Z → E isomerization of the natural system, it was possible to invert the directionality of the isomerization (E → Z) by simultaneously truncating the retinal scaffold, and introducing a third olefin substituent to augment A1,3-strain upon isomerization. Consequently, conjugation is reduced in the product chromophore leading to a substrate/product combination with discrete photophysical signatures. The operationally simple isomerization protocol has been applied to a variety of enone-derived substrates and showcased in the preparation of the medically relevant 4-substituted coumarin scaffold. A correlation of sensitizer triplet energy (ET) and reaction efficiency, together with the study of additive effects and mechanistic probes, is consistent with a triplet energy transfer mechanism.
Development of a palladium catalyzed addition of boronic acids to alkynyl esters: synthesis of trisubstituted olefins as single isomers
Bush, Alexander Graham,Jiang, Jojo Liu,Payne, Philippa R.,Ogilvie, William W.
scheme or table, p. 8502 - 8506 (2010/01/06)
Very small phosphine ligands allow access to single isomer trisubstituted olefins from alkynyl esters with complete control of both stereochemistry and regiochemistry. This method provides a convenient synthesis of single isomer trisubstituted olefins wit
Single-isomer trisubstituted olefins from a novel reaction of (E)-βchloro-α-iodo-α,β-unsaturated esters and amides
Simard-Mercier, Julie,Jiang, Jojo Liu,Ho, Michael L.,Flynn, Alison B.,Ogilvie, William W.
, p. 5899 - 5906 (2008/12/21)
(Chemical Equation Presented) (E)-β-Chloro-α-iodo-α, β-unsaturated esters are converted to single isomer trisubstituted olefins bearing three different carbon substituents by cross-coupling under reflux. Mechanistic investigations suggest that this process transfers a hydrogen from the boronic acid to the α-position of the substrate and then introduces an aryl group to the β-position of the intermediate template while replacing chloride. The reaction is highly stereoselective, showing preference for the E-isomer. The process proceeds through (E)-β-chloro-α-aryl-α, β-unsaturated esters that are transformed efficiently into the corresponding E-products through stereoselective Suzuki-type reactions giving single isomers. The observed stereo-chemistry is apparently enabled by the intermediacy of a palladium allenoate. The reaction involves a catalytic cycle in which PdII is reduced to Pd0 through the formation of biaryl-coupled products.
