@article {458,
	title = {Enhanced enantio- and diastereoselectivity via confinement and cation binding: Yang photocyclization of 2-benzoyladamantane derivatives within zeolites},
	journal = {Journal of Organic Chemistry},
	volume = {67},
	number = {24},
	year = {2002},
	note = {ISI Document Delivery No.: 620AATimes Cited: 5Cited Reference Count: 60},
	month = {Nov},
	pages = {8339-8350},
	type = {Article},
	abstract = {Irradiation of 2-benzoyladamantane derivatives in zeolites yields the endo-cyclobutanols as the only photoproduct via a gamma-hydrogen abstraction process. The cyclobutanols readily undergo retro-aldol reaction to give delta-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{\textquoteright}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 delta-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.},
	keywords = {ABSOLUTE ASYMMETRIC-SYNTHESIS, ACID-DERIVATIVES, CATALYSTS, COMPLEXES, EPOXIDATION, INDUCTION, PHOTOREACTIONS, SOLID-STATE, STATE ORGANIC-PHOTOCHEMISTRY, TROPOLONE ETHER},
	isbn = {0022-3263},
	url = {<Go to ISI>://000179509400006},
	author = {Natarajan, A. and Joy, A. and Kaanumalle, L. S. and Scheffer, J. R. and Ramamurthy, V.}
}
@article {4923,
	title = {Enantioselective photoelectrocyclization of a tropolone derivative in the crystalline state},
	journal = {Journal of Physical Organic Chemistry},
	volume = {13},
	number = {9},
	year = {2000},
	note = {ISI Document Delivery No.: 349GNTimes Cited: 5Cited Reference Count: 15},
	month = {Sep},
	pages = {531-538},
	type = {Article},
	abstract = {Achiral tropolone ethers are well known to undergo photochemically induced disrotatory electrocyclic ring closure in solution to form racemic bicyclo[3.2.0]hepta-3,6-dien-2-one derivatives. The present paper reports successful efforts to carry out this transformation enantioselectively through the use of the solid-state ionic chiral auxiliary method. in this method, the reactant, an achiral tropolone ether, is equipped with a carboxylic acid group to which an optically pure amine can be attached by salt formation. Salts such as these are required to crystallize in chiral space groups, which provide asymmetric reaction cavities capable of differentiating enantiomeric transition states. Irradiation of these materials in the solid state leads to enantiomerically enriched products in moderate to high enantiomeric excess depending on the amine employed. Of the amines studied, the best results were obtained with 1-phenylethylamine and 1-amido-2-indanol, which gave enantiomeric excesses in the 60-80\% range depending on the extent of conversion. Because the tropolone ring is planar, it is suggested that the stereochemical outcome of the electrocyclization in the solid state is governed by environmental crystal lattice effects rather than by the initial conformation of the reactant. Copyright (C) 2000 John Wiley \& Sons, Ltd.},
	keywords = {ALKYL ETHERS, ASYMMETRIC INDUCTION, crystalline tropolones, electrocyclic ring closure, enantioselective photoelectrocyclization, PHOTOCHEMISTRY, PHOTOREACTIONS, SOLID-STATE, YANG PHOTOCYCLIZATION REACTION},
	isbn = {0894-3230},
	url = {<Go to ISI>://000089037500007},
	author = {Scheffer, J. R. and Wang, L. T.}
}
@article {4844,
	title = {Photochemistry of a tropolone ether and 2,2-dimethyl-1-(2H)-naphthalenones within a zeolite: Enhanced diastereoselectivity via confinement},
	journal = {Journal of the American Chemical Society},
	volume = {122},
	number = {4},
	year = {2000},
	note = {ISI Document Delivery No.: 281MUTimes Cited: 56Cited Reference Count: 27},
	month = {Feb},
	pages = {728-729},
	type = {Article},
	keywords = {INDUCTION, PHOTOREACTIONS, SOLID-STATE},
	isbn = {0002-7863},
	url = {<Go to ISI>://000085165200030},
	author = {Joy, A. and Uppili, S. and Netherton, M. R. and Scheffer, J. R. and Ramamurthy, V.}
}
