53140-72-0Relevant articles and documents
Enhanced enantio- and diastereoselectivity via confinement and cation binding: Yang photocyclization of 2-benzoyladamantane derivatives within zeolites
Natarajan, Arunkumar,Joy, Abraham,Kaanumalle, Lakshmi S.,Scheffer, John R.,Ramamurthy
, p. 8339 - 8350 (2007/10/03)
Irradiation of 2-benzoyladamantane derivatives in zeolites yields the endo-cyclobutanols as the only photoproduct via a γ-hydrogen abstraction process. The cyclobutanols readily undergo retroaldol reaction to give δ-ketoesters. The enantiomeric excess (ee) in the endo-cyclobutanols is measured by monitoring the ee in the ketoesters. Whereas in solution the ee in the product ketoester is zero, within achiral NaY zeolite, in the presence of a chiral inductor such as pseudoephedrine, ee's up to 28% have been obtained. The influence of zeolite on several chiral esters of 2-benzoyladamantane-2-carboxylic acids has also been examined. Whereas in solution the diastereomeric excess is 15%, in zeolite the δ-ketoesters are obtained in 79% de (best examples). Ab initio computations suggest that enhancement of chiral induction within zeolites is likely to be due to cation complexation with the reactant ketone. Alkali ion-organic interaction, a powerful tool, is waiting to be fully exploited in photochemical and thermal reactions. In this context zeolites could be a useful medium as one could view them as a reservoir of "naked" alkali ions that are only partially coordinated to the zeolite walls.
Face Selection in the Capture of Anionic Carbon
Bodepudi, Vani R.,Noble, William J. le
, p. 3265 - 3269 (2007/10/02)
Several reactions of 2-(5-phenyladamantyl) derivatives have been examined with the objective of determining the stereochemistry of addition of electrophiles to a trigonal center C2 carrying a full or partial negative charge.These reactions included the ca
