@article {2480, title = {Enamides and Enesulfonamides as Nucleophiles: Formation of Complex Ring Systems through a Platinum(II)-Catalyzed Addition/Friedel-Crafts Pathway}, journal = {Journal of Organic Chemistry}, volume = {74}, number = {18}, year = {2009}, note = {ISI Document Delivery No.: 492LATimes Cited: 5Cited Reference Count: 90Kozak, Jennifer A. Dodd, Jennifer M. Harrison, Tyler J. Jardine, Katherine J. Patrick, Brian O. Dake, Gregory R.}, month = {Sep}, pages = {6929-6935}, type = {Article}, abstract = {Cyclic enamine derivatives (enesulfonamides and enamides) tethered to an 1-arylalkynyl fragment undergo a platinum(II)-catalyzed tandem alkyne addition/Friedel-Crafts ring closure to form nitrogen-containing polycyclic structures. Regioselectivity in the initial addition of the enesulfonamide or enamide nucleophile to the platinum(II)-alkyne complex is important. Electron-rich arenes and heterocycles led to the formation of products resulting from an Initial 6-endo cyclization. Twenty-three examples of this process are presented.}, keywords = {CATALYZED CYCLOISOMERIZATIONS, CLOSING, CYCLIZATION ROUTE, DIASTEREOSELECTIVE SYNTHESIS, ELECTRON-RICH OLEFINS, ENANTIOSELECTIVE REACTIONS, LYCOPODIUM ALKALOIDS, METATHESIS, N-ACYL-ENAMINES, NITROGEN-HETEROCYCLES, REARRANGEMENTS, SKELETAL}, isbn = {0022-3263}, url = {://000269656400004}, author = {Kozak, J. A. and Dodd, J. M. and Harrison, T. J. and Jardine, K. J. and Patrick, B. O. and Dake, G. R.} } @article {4508, title = {Asymmetric induction in the solid state photochemistry of an alpha-mesitylacetophenone derivative through the use of ionic chiral auxiliaries}, journal = {Tetrahedron Letters}, volume = {40}, number = {50}, year = {1999}, note = {ISI Document Delivery No.: 258FJTimes Cited: 15Cited Reference Count: 8}, month = {Dec}, pages = {8733-8736}, type = {Article}, abstract = {Irradiation in the crystalline state of salts formed between alpha-mesitylacetophenone-p-carboxylic acid and a variety of optically pure amines - the so-called {\textquoteright}ionic chiral auxiliary{\textquoteright} approach to asymmetric synthesis - leads to the corresponding 2-indanol in excellent yield and in high enantiomeric excess. X-Ray crystallography reveals the source of the enantioselectivity. (C) 1999 Elsevier Science Ltd. All rights reserved.}, keywords = {ASYMMETRIC INDUCTION, CARBOXYLATE, CRYSTAL, KETONES, PHOTOCHEMISTRY, REARRANGEMENTS}, isbn = {0040-4039}, url = {://000083827200004}, author = {Cheung, E. and Rademacher, K. and Scheffer, J. R. and Trotter, J.} } @article {4508, title = {Asymmetric induction in the solid state photochemistry of an alpha-mesitylacetophenone derivative through the use of ionic chiral auxiliaries}, journal = {Tetrahedron Letters}, volume = {40}, number = {50}, year = {1999}, note = {ISI Document Delivery No.: 258FJTimes Cited: 15Cited Reference Count: 8}, month = {Dec}, pages = {8733-8736}, type = {Article}, abstract = {Irradiation in the crystalline state of salts formed between alpha-mesitylacetophenone-p-carboxylic acid and a variety of optically pure amines - the so-called {\textquoteright}ionic chiral auxiliary{\textquoteright} approach to asymmetric synthesis - leads to the corresponding 2-indanol in excellent yield and in high enantiomeric excess. X-Ray crystallography reveals the source of the enantioselectivity. (C) 1999 Elsevier Science Ltd. All rights reserved.}, keywords = {ASYMMETRIC INDUCTION, CARBOXYLATE, CRYSTAL, KETONES, PHOTOCHEMISTRY, REARRANGEMENTS}, isbn = {0040-4039}, url = {://000083827200004}, author = {Cheung, E. and Rademacher, K. and Scheffer, J. R. and Trotter, J.} } @article {3679, title = {Cation to anion triplet-triplet energy transfer in crystalline organic salts}, journal = {Tetrahedron Letters}, volume = {37}, number = {34}, year = {1996}, note = {ISI Document Delivery No.: VC820Times Cited: 4Cited Reference Count: 7}, month = {Aug}, pages = {6037-6040}, type = {Article}, abstract = {Irradiation of crystalline salts formed between sensitizer-linked amines and photochemically reactive carboxylic acids at wavelengths where only the sensitizers absorb leads to characteristic triplet state reactivity of the carboxylate anions. Copyright (C) 1996 Elsevier Science Ltd}, keywords = {REARRANGEMENTS}, isbn = {0040-4039}, url = {://A1996VC82000003}, author = {Gamlin, J. N. and Olovsson, G. and Pitchumani, K. and Ramamurthy, V. and Scheffer, J. R. and Trotter, J.} } @article {3679, title = {Cation to anion triplet-triplet energy transfer in crystalline organic salts}, journal = {Tetrahedron Letters}, volume = {37}, number = {34}, year = {1996}, note = {ISI Document Delivery No.: VC820Times Cited: 4Cited Reference Count: 7}, month = {Aug}, pages = {6037-6040}, type = {Article}, abstract = {Irradiation of crystalline salts formed between sensitizer-linked amines and photochemically reactive carboxylic acids at wavelengths where only the sensitizers absorb leads to characteristic triplet state reactivity of the carboxylate anions. Copyright (C) 1996 Elsevier Science Ltd}, keywords = {REARRANGEMENTS}, isbn = {0040-4039}, url = {://A1996VC82000003}, author = {Gamlin, J. N. and Olovsson, G. and Pitchumani, K. and Ramamurthy, V. and Scheffer, J. R. and Trotter, J.} } @article {2874, title = {AN ENANTIOSPECIFIC SYNTHESIS OF 4-METHYLCAMPHOR}, journal = {Tetrahedron-Asymmetry}, volume = {4}, number = {11}, year = {1993}, note = {ISI Document Delivery No.: MJ468Times Cited: 10Cited Reference Count: 38}, month = {Nov}, pages = {2363-2370}, type = {Article}, abstract = {Treatment of (-)-2-methylenebornane (7), derived from (+)-camphor (1), with 45\% HBr /HOAc results in Wagner-Meerwein rearrangement and formation of 4-methylisobornyl bromide (17) in 80-90\% yield. The enantiopurity of (17) was determined by conversion to (+)-4-methylisoborneol (5) and (-)-4-methylcamphor (3).}, keywords = {CAMPHOR DERIVATIVES, ESTERS, KETONES, NATURAL PRODUCT SYNTHESIS, POTASSIUM, REARRANGEMENTS, ROUTE, STEROID-SYNTHESIS, SYNTHONS}, isbn = {0957-4166}, url = {://A1993MJ46800024}, author = {Money, T. and Palme, M. H.} } @article {7193, title = {CONTROL OF REGIOSELECTIVITY THROUGH RELIEF OF STERIC CROWDING IN THE DI-PI-METHANE PHOTOREARRANGEMENT OF 9,10-ETHENOANTHRACENE DERIVATIVES}, journal = {Tetrahedron Letters}, volume = {33}, number = {12}, year = {1992}, note = {ISI Document Delivery No.: HJ784Times Cited: 4Cited Reference Count: 13}, month = {Mar}, pages = {1535-1538}, type = {Article}, abstract = {Product structures and quantum yields for the solution phase di-pi-methane photorearrangement of the 9,10-ethenoanthracene derivatives 1-4 have been determined. The results are consistent with a model in which relief of steric crowding is the factor that governs regioselectivity.}, keywords = {BICYCLIC SYSTEMS, NITROBENZOATES, REARRANGEMENTS, solvolysis}, isbn = {0040-4039}, url = {://A1992HJ78400002}, author = {Chen, J. X. and Pokkuluri, P. R. and Scheffer, J. R. and Trotter, J.} } @article {7193, title = {CONTROL OF REGIOSELECTIVITY THROUGH RELIEF OF STERIC CROWDING IN THE DI-PI-METHANE PHOTOREARRANGEMENT OF 9,10-ETHENOANTHRACENE DERIVATIVES}, journal = {Tetrahedron Letters}, volume = {33}, number = {12}, year = {1992}, note = {ISI Document Delivery No.: HJ784Times Cited: 4Cited Reference Count: 13}, month = {Mar}, pages = {1535-1538}, type = {Article}, abstract = {Product structures and quantum yields for the solution phase di-pi-methane photorearrangement of the 9,10-ethenoanthracene derivatives 1-4 have been determined. The results are consistent with a model in which relief of steric crowding is the factor that governs regioselectivity.}, keywords = {BICYCLIC SYSTEMS, NITROBENZOATES, REARRANGEMENTS, solvolysis}, isbn = {0040-4039}, url = {://A1992HJ78400002}, author = {Chen, J. X. and Pokkuluri, P. R. and Scheffer, J. R. and Trotter, J.} } @article {7244, title = {PROTOTROPIC CONTROL OF ORGANIC-PHOTOCHEMISTRY - HYDROGEN-BONDING EFFECTS ON THE DI-PI-METHANE PHOTOREARRANGEMENT}, journal = {Journal of Organic Chemistry}, volume = {57}, number = {1}, year = {1992}, note = {ISI Document Delivery No.: GY184Times Cited: 6Cited Reference Count: 54}, month = {Jan}, pages = {241-247}, type = {Article}, abstract = {The IR and UV spectra as well as the photochemistry of the isopropyl monoester of dibenzobarrelene dicarboxylic acid 2 were analyzed in detail in several media. A correlation was found between the photochemical results and the spectroscopically detected hydrogen-bonded structures of 2. An equilibrium between dimeric (2-HD) and intramolecularly hydrogen bonded (2-HI) structures was detected by IR spectroscopy in nonpolar solvents having weak hydrogen-bond-accepting capabilities. The ratio of the two regioisomeric dibenzosemibullvalene products 3 and 4 formed in the di-pi-methane photorearrangement of 2 was found to correlate with such an equilibrium, and it was concluded that intramolecular (2-HI) and dimeric (2-HD) hydrogen-bonded structures display significantly different photochemical reactivity. The infrared spectra and the photoproduct ratio in polar solvents possessing hydrogen-bond-accepting capabilities (e.g., acetonitrile), on the other hand, turned out to be concentration independent. High regioselectivity was found in the solid state where the dimer 2-HD is the only species, leading to 4 as the major product. In contrast, 3 was obtained preferentially in aqueous sodium bicarbonate solutions where 2 exists as the carboxylate anion. Supporting evidence regarding the different hydrogen bonding arrangements in 2 was found in the solvent effects on its UV spectra.}, keywords = {ABSORPTION, DIBENZOBARRELENES, EXCITED-STATE, LASER EXCITATION FLUORESCENCE, METHYL SALICYLATE, ORTHO-HYDROXYBENZALDEHYDE, PHOTOISOMERIZATION, REARRANGEMENTS, SOLID-STATE, STATE PROTON-TRANSFER}, isbn = {0022-3263}, url = {://A1992GY18400043}, author = {Garciagaribay, M. A. and Scheffer, J. R. and Watson, D. G.} }