@inbook {1243,
	title = {Asymmetric induction in organic photochemistry via the solid-state ionic chiral auxiliary approach},
	booktitle = {Organic Solid State Reactions},
	series = {Topics in Current Chemistry},
	volume = {254},
	year = {2005},
	note = {ISI Document Delivery No.: BCP68Times Cited: 29Cited Reference Count: 57ReviewHEIDELBERGER PLATZ 3, D-14197 BERLIN, GERMANY},
	pages = {233-262},
	publisher = {Springer-Verlag Berlin},
	organization = {Springer-Verlag Berlin},
	address = {Berlin},
	abstract = {After a brief introduction and summary of various methods of asymmetric induction in organic photochemistry, the main part of the review covers the solid-state ionic chiral auxiliary approach to asymmetric photochemical synthesis. Application of this technique to the Norrish type II reaction, as well as to the di-Ti-methane and oxa-di-pi-methane photorearrangements, and the Cis, trans-photoisomerization of diarylcyclopropane derivatives is presented and discussed.},
	keywords = {ABSOLUTE-CONFIGURATION, ACHIRAL, AMMONIUM CARBOXYLATE SALTS, ASYMMETRIC INDUCTION, auxiliaries, crystal structure-reactivity correlations, CRYSTALLINE STATE, di-pi-methane, ionic chiral, MODIFIED ZEOLITES, MOLECULES, organic photochemistry, PHOTOCYCLIZATION, SINGLE-CRYSTALS, solid state, STRUCTURE-REACTIVITY RELATIONSHIPS, TROPOLONE ETHER},
	isbn = {0340-1022},
	url = {<Go to ISI>://000230596800007},
	author = {Scheffer, J. R. and Xia, W. J.}
}
@article {1304,
	title = {Asymmetric synthesis of dihydrofurans via a formal retro-Claisen photorearrangement},
	journal = {Journal of the American Chemical Society},
	volume = {127},
	number = {8},
	year = {2005},
	note = {ISI Document Delivery No.: 901URTimes Cited: 13Cited Reference Count: 36},
	month = {Mar},
	pages = {2725-2730},
	type = {Article},
	abstract = {Solution-phase irradiation of a series of syn-7-benzoylnorbornene derivatives is shown to lead to cis-fused dihydrofuran derivatives in low quantum but excellent chemical yields in what is formally a retro-Claisen rearrangement. In analogy to the well-known Paterno-Buchi reaction, the first step of the rearrangement is suggested to involve (n,pi*)(3)-mediated addition of the carbonyl oxygen to the norbornene double bond, producing a triplet 1,4-biradical. This intermediate, rather than closing to the oxetane, undergoes cleavage accompanied by intersystem crossing to form the dihydrofuran. To determine whether the retro-Claisen photorearrangement could be carried out enantioselectively, the 7-benzoylnorbornene reactant was equipped with a para-carboxylic acid substituent to which a series of optically pure amines was attached ionically via salt bridges. Irradiation of these salts in the crystalline state followed by diazomethane workup (the solid-state ionic chiral auxiliary method) was shown to afford the corresponding dihydrofuran in optical yields as high as 93\% at 95\% conversion. X-ray crystallography revealed that the enantioselectivity arises from crystallization of the reactant in a conformation in which the carbonyl oxygen is more favorably oriented for bond formation to one end of the norbornene double bond than the other, thus leading to a predominance of a single enantiomer.},
	keywords = {FURANS, GENERAL-APPROACH, INDUCTION, PHENYL KETONES, PHOTOCHEMISTRY, PHOTOCYCLIZATION, REARRANGEMENT, SOLID-STATE},
	isbn = {0002-7863},
	url = {<Go to ISI>://000227308100059},
	author = {Xia, W. J. and Yang, C. and Patrick, B. O. and Scheffer, J. R. and Scott, C.}
}
@article {1075,
	title = {Photochemistry of 9-methylbicyclo[3.3.1]nonyl aryl ketones - A novel 1,5-disproportionation of 1,4-hydroxy biradicals and asymmetric induction using the solid-state ionic chiral auxiliary method},
	journal = {Canadian Journal of Chemistry-Revue Canadienne De Chimie},
	volume = {83},
	number = {9},
	year = {2005},
	note = {ISI Document Delivery No.: 001VETimes Cited: 4Cited Reference Count: 29},
	month = {Sep},
	pages = {1460-1472},
	type = {Article},
	abstract = {A novel 1.5-disproportionation reaction has been discovered for 1,4-hydroxy biradicals derived from the photolysis of 9-methylbicyclo[3.3.1]nonyl phenyl ketones (1), which undergo mainly Yang cyclization both in Solution and the solid state. By applying the solid-state ionic chiral auxiliary method of asymmetric synthesis to the Yang cyclization, enantiomeric excesses as high as 95\% were achieved at high reaction conversions. The origin of the reaction selectivity is discussed with the help of X-ray crystallography. In addition, the solid-state photoreaction of ketone 1b was found to occur in a single crystal-to-single crystal fashion.},
	keywords = {1, 4-hydroxy biradical, asymmetric, BEHAVIOR, CRYSTAL-STRUCTURE, disproportionation, HYDROGEN-BOND, INDUCTION, ionic chiral auxiliary, PHOTOCHEMISTRY, PHOTOCYCLIZATION, reaction, REACTIVITY CORRELATIONS, SALTS, single crystal-to-single crystal},
	isbn = {0008-4042},
	url = {<Go to ISI>://000234570000030},
	author = {Chen, S. and Patrick, B. O. and Scheffer, J. R.}
}
@article {811,
	title = {1,4-hydroxybiradical behavior revealed through crystal structure - Solid-state reactivity correlations},
	journal = {Journal of the American Chemical Society},
	volume = {126},
	number = {11},
	year = {2004},
	note = {ISI Document Delivery No.: 804GETimes Cited: 21Cited Reference Count: 27},
	month = {Mar},
	pages = {3511-3520},
	type = {Article},
	abstract = {Structure- reactivity correlations for triplet 1,4-hydroxybiradicals in solution are made difficult by the presence of multiple reactive conformers and the possibility of conformation-dependent intersystem crossing. These problems can be overcome by working in the crystalline state, where the conformations of the 1,4-hydroxybiradicals are fixed and determinable by X-ray crystallography of the parent ketones, assuming that hydrogen atom abstraction occurs with little or no change in conformation. This approach is applied to 15 bi- and tricyclic ketones designed to have slightly different biradical conformations, so that the effect of small and incremental changes in geometry on biradical behaviour can be tested. The results indicate that, while geometry does have a strong influence on 1,4-hydroxybiradical partitioning between cyclization, cleavage, and reverse hydrogen transfer, a full understanding of the results requires that the strain involved in forming the cyclization products be taken into account.},
	keywords = {4-BIRADICALS, BIRADICALS, CONFORMATIONAL MEMORY, GEOMETRIC REQUIREMENTS, II REACTION, ORGANIC-SYNTHESIS, PHENYL KETONES, PHOTOCHEMISTRY, PHOTOCYCLIZATION, STEREOSELECTIVITY, TRIPLET 1},
	isbn = {0002-7863},
	url = {<Go to ISI>://000220286400046},
	author = {Braga, D. and Chen, S. and Filson, H. and Maini, L. and Netherton, M. R. and Patrick, B. O. and Scheffer, J. R. and Scott, C. and Xia, W. J.}
}
@article {727,
	title = {The photochemistry of trans-1,4,4,4-tetraphenylbut-2-en-1-one: A highly efficient aryl migration (type B) enone photorearrangement},
	journal = {Canadian Journal of Chemistry-Revue Canadienne De Chimie},
	volume = {81},
	number = {6},
	year = {2003},
	note = {ISI Document Delivery No.: 706UATimes Cited: 0Cited Reference Count: 18},
	month = {Jun},
	pages = {705-708},
	type = {Article},
	abstract = {Photolysis of trans-1,4,4,4-tetraphenylbut-2-en-1-one (3) in acetonitrile or benzene leads to trans-cis isomerization (7) along with rearrangement to trans-1 -benzoyl-2,2,3-triphenylcyclopropane(8). Formation of the latter product represents a new example of the aryl migration (type B) enone photorearrangement reaction first reported by Zimmerman and co-workers for 4,4-diphenylcyclohex-2-en-1-one (1). The quantum yield in the case of enone 3 (0.4) is approximately 10 times greater than that for 4,4,-diphenylcyclohex-2-en-1-one, a result that is ascribed to steric acceleration of phenyl migration from the triphenylmethyl group plus greater resonance stabilization of the intermediate biradical.},
	keywords = {aryl migration, ASYMMETRIC INDUCTION, di-pi-methane, enone, EXPLORATORY ORGANIC PHOTOCHEMISTRY, MECHANISM, MIGRATION, PHENYL, PHOTOCHEMISTRY, PHOTOCYCLIZATION, REARRANGEMENT, STATE},
	isbn = {0008-4042},
	url = {<Go to ISI>://000184472400035},
	author = {Scheffer, J. R. and Vishnumurthy, K.}
}
@article {710,
	title = {Preorganization of achiral molecules for asymmetric synthesis through crystallization-induced immobilization in homochiral conformations},
	journal = {Angewandte Chemie-International Edition},
	volume = {42},
	number = {32},
	year = {2003},
	note = {ISI Document Delivery No.: 716PRTimes Cited: 19Cited Reference Count: 24},
	pages = {3775-3777},
	type = {Article},
	keywords = {asymmetric synthesis, CRYSTAL, crystal engineering, GEOMETRIC REQUIREMENTS, II, INDUCTION, KETONES, PHOTOCHEMICAL-REACTIONS, PHOTOCHEMISTRY, PHOTOCYCLIZATION, reaction, REACTIONS, REACTIVITY, SOLID-STATE, topochemistry},
	isbn = {1433-7851},
	url = {<Go to ISI>://000185038000009},
	author = {Patrick, B. O. and Scheffer, J. R. and Scott, C.}
}
@article {459,
	title = {Control of enantioselectivity in the photochemical conversion of alpha-oxoamides into beta-lactam derivatives},
	journal = {Organic Letters},
	volume = {4},
	number = {9},
	year = {2002},
	note = {ISI Document Delivery No.: 545XYTimes Cited: 19Cited Reference Count: 34},
	month = {May},
	pages = {1443-1446},
	type = {Article},
	abstract = {[GRAPHIC] Several approaches to asymmetric induction in the alpha-oxoamide (1) to beta-lactam (2) photorearrangement are described. Best results are obtained via irradiation of ionic and covalent chiral auxiliary-containing reactants in the crystalline state and in the interior supercages of zeolites.},
	keywords = {AMINO-ACID, ASYMMETRIC INDUCTION, CATION-PI INTERACTIONS, CRYSTALLINE STATE, GAS-PHASE, GEOMETRIC REQUIREMENTS, II, PHOTOCYCLIZATION, REACTIONS, SOLID-STATE PHOTOCHEMISTRY, ZWITTERIONS},
	isbn = {1523-7060},
	url = {<Go to ISI>://000175243900009},
	author = {Natarajan, A. and Wang, K. and Ramamurthy, V. and Scheffer, J. R. and Patrick, B.}
}
@article {5187,
	title = {Enantioselective photochemical synthesis of a beta-lactam via the solid state ionic chiral auxiliary method},
	journal = {Synthesis-Stuttgart},
	number = {8},
	year = {2001},
	note = {ISI Document Delivery No.: 448GETimes Cited: 12Cited Reference Count: 20Sp. Iss. SI},
	pages = {1253-1257},
	type = {Article},
	abstract = {Photolysis of crystals of a carboxylic acid-containing N,N-dialkylarylglyoxylamide to which an optically pure ammonium ion (the ionic chiral auxiliary) has been attached through a salt bridge leads to a 91\% isolated yield of a beta -lactam in greater than 99\% enantiomeric excess. Suspension of the crystals in hexane allows the photoreaction to be carried out on a 500 mg scale, thus demonstrating the synthetic utility of the solid stare ionic chiral auxiliary approach to asymmetric synthesis.},
	keywords = {ACHIRAL OXO AMIDE, ACID, asymmetric synthesis, beta-lactam, chiral auxiliaries, CRYSTALLINE STATE, HOST, INCLUSION COMPLEXES, PHOTOCHEMISTRY, PHOTOCYCLIZATION, solid state},
	isbn = {0039-7881},
	url = {<Go to ISI>://000169617900022},
	author = {Scheffer, J. R. and Wang, K. Y.}
}
@article {4573,
	title = {The Norrish type II reaction in the crystalline state: Toward a better understanding of the geometric requirements for gamma-hydrogen atom abstraction},
	journal = {Tetrahedron},
	volume = {55},
	number = {4},
	year = {1999},
	note = {ISI Document Delivery No.: 159BRTimes Cited: 69Cited Reference Count: 58},
	month = {Jan},
	pages = {885-907},
	type = {Article},
	abstract = {By correlating the success or failure of the Norrish type II reaction for a series of compounds in the crystalline state with geometric data derived from X-ray crystallography (the so-called Crystal Structure-Solid State Reactivity Method), the distance and angular requirements for photochemical gamma-hydrogen atom abstraction have been established. These studies indicate that abstractions are preferred when the C=O ... H-gamma, distance is close to the sum of the van der Waals radii of hydrogen and oxygen (2.72 Angstrom), and that the gamma-hydrogen atom can deviate by as much as 50-60 degrees from the plane containing the oxygen n-orbital responsible for abstraction. Because molecular conformations and interatomic distances and angles can be calculated readily by using empirical force field methods, such data permit predictions to be made concerning the outcome of hypothetical Norrish type II processes. (C) 1999 Elsevier Science Ltd. All rights reserved.},
	keywords = {ABSOLUTE ASYMMETRIC-SYNTHESIS, CONFORMATIONAL CONTROL, ENVIRONMENT, KETONES, METHODOLOGY, MOLECULES, PHOTOCHEMISTRY, PHOTOCYCLIZATION, SOLID-STATE, SPECTRA},
	isbn = {0040-4020},
	url = {<Go to ISI>://000078152400001},
	author = {Ihmels, H. and Scheffer, J. R.}
}
@article {4093,
	title = {Novel differences between the solid state and solution phase photochemistry of 1,2-cyclodecanedione},
	journal = {Tetrahedron Letters},
	volume = {38},
	number = {37},
	year = {1997},
	note = {ISI Document Delivery No.: XW044Times Cited: 8Cited Reference Count: 8},
	month = {Sep},
	pages = {6549-6552},
	type = {Article},
	abstract = {1,2-Cyclodecanedione (1) undergoes a novel photorearrangement in the crystalline state that is different from the Norrish/Yang type II photocyclization process observed in solution. A possible mechanism is presented and discussed. (C) 1997 Elsevier Science Ltd.},
	keywords = {ALPHA-DIKETONES, PHOTOCYCLIZATION},
	isbn = {0040-4039},
	url = {<Go to ISI>://A1997XW04400021},
	author = {Olovsson, G. and Scheffer, J. R. and Trotter, J. and Wu, C. H.}
}
@article {4093,
	title = {Novel differences between the solid state and solution phase photochemistry of 1,2-cyclodecanedione},
	journal = {Tetrahedron Letters},
	volume = {38},
	number = {37},
	year = {1997},
	note = {ISI Document Delivery No.: XW044Times Cited: 8Cited Reference Count: 8},
	month = {Sep},
	pages = {6549-6552},
	type = {Article},
	abstract = {1,2-Cyclodecanedione (1) undergoes a novel photorearrangement in the crystalline state that is different from the Norrish/Yang type II photocyclization process observed in solution. A possible mechanism is presented and discussed. (C) 1997 Elsevier Science Ltd.},
	keywords = {ALPHA-DIKETONES, PHOTOCYCLIZATION},
	isbn = {0040-4039},
	url = {<Go to ISI>://A1997XW04400021},
	author = {Olovsson, G. and Scheffer, J. R. and Trotter, J. and Wu, C. H.}
}
@article {3973,
	title = {Phenyl[2,4,6-tris(1-methylethyl)phenyl]methanethione and 4-methoxyphenyl[2,4,6-tris(1-methylethyl)phenyl]methanethione},
	journal = {Acta Crystallographica Section C-Crystal Structure Communications},
	volume = {53},
	year = {1997},
	note = {ISI Document Delivery No.: XZ627Times Cited: 4Cited Reference Count: 15Part 9},
	month = {Sep},
	pages = {1257-1259},
	type = {Article},
	abstract = {The two title compounds, C22H28S and C23H30OS, respectively, have almost identical molecular structures, but different crystal structures. The two parts of each molecule are approximately perpendicular to each other, with S ...gamma H distances of 3.06 and 3.02 Angstrom, respectively, suitable for H-atom abstraction in photochemical reactions.},
	keywords = {PHOTOCHEMISTRY, PHOTOCYCLIZATION, STATE},
	isbn = {0108-2701},
	url = {<Go to ISI>://A1997XZ62700041},
	author = {Fu, T. Y. and Scheffer, J. R. and Trotter, J.}
}
@article {3973,
	title = {Phenyl[2,4,6-tris(1-methylethyl)phenyl]methanethione and 4-methoxyphenyl[2,4,6-tris(1-methylethyl)phenyl]methanethione},
	journal = {Acta Crystallographica Section C-Crystal Structure Communications},
	volume = {53},
	year = {1997},
	note = {ISI Document Delivery No.: XZ627Times Cited: 4Cited Reference Count: 15Part 9},
	month = {Sep},
	pages = {1257-1259},
	type = {Article},
	abstract = {The two title compounds, C22H28S and C23H30OS, respectively, have almost identical molecular structures, but different crystal structures. The two parts of each molecule are approximately perpendicular to each other, with S ...gamma H distances of 3.06 and 3.02 Angstrom, respectively, suitable for H-atom abstraction in photochemical reactions.},
	keywords = {PHOTOCHEMISTRY, PHOTOCYCLIZATION, STATE},
	isbn = {0108-2701},
	url = {<Go to ISI>://A1997XZ62700041},
	author = {Fu, T. Y. and Scheffer, J. R. and Trotter, J.}
}
@article {3675,
	title = {Crystal structure-reactivity relationships in the solid state photochemistry of 2,4,6-triisopropylthiobenzophenone: C=O...H versus C=S...H abstraction geometry},
	journal = {Tetrahedron Letters},
	volume = {37},
	number = {13},
	year = {1996},
	note = {ISI Document Delivery No.: UC590Times Cited: 6Cited Reference Count: 19},
	month = {Mar},
	pages = {2125-2128},
	type = {Article},
	abstract = {X-ray crystal structure solid state photoreactivity correlations are reported for 2,4,6-triisopropylthiobenzophenone (1a) and its p-methoxy derivative 1b. The results reveal interesting differences in the geometry of gamma-hydrogen atom abstraction for ketones and thiones.},
	keywords = {2, 4, 6-TRIISOPROPYLBENZOPHENONES, CONFORMATION, KETONES, PHOTOCYCLIZATION, TRIPLET-STATES},
	isbn = {0040-4039},
	url = {<Go to ISI>://A1996UC59000003},
	author = {Fu, T. Y. and Scheffer, J. R. and Trotter, J.}
}
@article {3675,
	title = {Crystal structure-reactivity relationships in the solid state photochemistry of 2,4,6-triisopropylthiobenzophenone: C=O...H versus C=S...H abstraction geometry},
	journal = {Tetrahedron Letters},
	volume = {37},
	number = {13},
	year = {1996},
	note = {ISI Document Delivery No.: UC590Times Cited: 6Cited Reference Count: 19},
	month = {Mar},
	pages = {2125-2128},
	type = {Article},
	abstract = {X-ray crystal structure solid state photoreactivity correlations are reported for 2,4,6-triisopropylthiobenzophenone (1a) and its p-methoxy derivative 1b. The results reveal interesting differences in the geometry of gamma-hydrogen atom abstraction for ketones and thiones.},
	keywords = {2, 4, 6-TRIISOPROPYLBENZOPHENONES, CONFORMATION, KETONES, PHOTOCYCLIZATION, TRIPLET-STATES},
	isbn = {0040-4039},
	url = {<Go to ISI>://A1996UC59000003},
	author = {Fu, T. Y. and Scheffer, J. R. and Trotter, J.}
}
