167563-03-3Relevant academic research and scientific papers
Chirality Transfer in Gold(I)-Catalysed Direct Allylic Etherifications of Unactivated Alcohols: Experimental and Computational Study
Barker, Graeme,Johnson, David G.,Young, Paul C.,Macgregor, Stuart A.,Lee, Ai-Lan
, p. 13748 - 13757 (2015/09/22)
Gold(I)-catalysed direct allylic etherifications have been successfully carried out with chirality transfer to yield enantioenriched, γ-substituted secondary allylic ethers. Our investigations include a full substrate-scope screen to ascertain substituent effects on the regioselectivity, stereoselectivity and efficiency of chirality transfer, as well as control experiments to elucidate the mechanistic subtleties of the chirality-transfer process. Crucially, addition of molecular sieves was found to be necessary to ensure efficient and general chirality transfer. Computational studies suggest that the efficiency of chirality transfer is linked to the aggregation of the alcohol nucleophile around the reactive π-bound Au-allylic ether complex. With a single alcohol nucleophile, a high degree of chirality transfer is predicted. However, if three alcohols are present, alternative proton transfer chain mechanisms that Erode the efficiency of chirality transfer become competitive.
Steric and Electronic Effects in Conformational Preferences of C1-Oxygenated Chiral Alkenes
Gung, Benjamin W.,Melnick, Jason P.,Wolf, Mark A.,King, Amanda
, p. 1947 - 1951 (2007/10/02)
A variable temperature NMR study shows that the benzyl protective group on the hydroxy function of a chiral allylic alcohol enhances the CH eclipsed from (I).On the other hand, various silyl ethers enhance the preference for the CO eclipsed conformer.However, when both the allylic R group and the hydroxy protective group are bulky (R = tert-butyl, P = TIPS), the staggered conformation of the chiral alkene becomes preferred.An acetate group does not have an apparent effect on the conformational preference of the protected allylic alcohol.These facts are explained in terms of steric and electronic interactions.
