Zobrazeno 1 - 10
of 21
pro vyhledávání: '"Joann M. Um"'
Autor:
Fabian Spänig, Joann M. Um, Chao-Kuan Tsai, Dirk M. Guldi, Ryan M. Hoekstra, K. N. Houk, Miguel A. Garcia-Garibay, Gregory Kuzmanich
Publikováno v:
Journal of the American Chemical Society. 133:2342-2345
Photoinduced decarbonylation of 2,4-bis(spirocyclohexyl)-1,3-cyclobutanedione 1 in the crystalline solid state resulted in formation of a deep blue transient with λ(max) = 550 nm and a half-life of 42 min at 298 K, identified as kinetically stabiliz
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_dedup___::3e9722a4b88e8987b98312fdee0274af
https://doi.org/10.1021/ja109494b
https://doi.org/10.1021/ja109494b
Autor:
Joann M. Um, Steven J. Coote, Nigel J. Reynolds, Christopher D. Bray, David M. Hodgson, Nicholas D. Kindon, K. N. Houk
Publikováno v:
The Journal of Organic Chemistry. 74:1019-1028
A new reactivity mode of hindered lithium amides with terminal epoxides is described whereby aldehyde enamines are produced via a previously unrecognized reaction pathway. Some of these aldehyde enamines display unprecedented C-alkylation reactivity
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_dedup___::4905d25a1c415a8220341db4e0993b34
https://doi.org/10.1021/jo802016t
https://doi.org/10.1021/jo802016t
Autor:
David A. Conlon, Frederick W. Hartner, Philip J. Pye, David L. Hughes, Nobuyoshi Yasuda, Joann M. Um, Michael Palucki, Yi Hsiao, Nelo R. Rivera, Mark S. Jensen, Fuh-Rong Tsay, Chunhua Yang
Publikováno v:
Chirality. 17:S149-S158
The asymmetric synthesis of a Merck anti-HIV drug candidate is described. The target molecule contains four stereogenic centers, three of which are located in a highly functionalized cyclopentane unit. The convergent synthesis involves the preparatio
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_dedup___::8296b256364b63a518562bb20b72cfce
https://doi.org/10.1002/chir.20137
https://doi.org/10.1002/chir.20137
Autor:
David A. Conlon, Michael Palucki, Jian Wang, Nobuyoshi Yasuda, Bing Mao, Joann M. Um, David L. Hughes, Paul J. Reider
Publikováno v:
Advanced Synthesis & Catalysis. 343:46-50
Molybdenum-catalyzed asymmetric allylic alkylation reactions were carried out using the inexpensive, air-stable, and readily available Mo(CO)6 as precatalyst. In situ IR was used to determine the required activation time and temperature required to a
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_________::a66bdc314a360e3c851181ba270a82d5
https://doi.org/10.1002/1615-4169(20010129)343:1<46::aid-adsc46>3.0.co
https://doi.org/10.1002/1615-4169(20010129)343:1<46::aid-adsc46>3.0.co
The energetics of the Diels-Alder cycloaddition reactions of several 1,3-dienes with acrylonitrile, and the energetics of formation of diradicals, were investigated with density functional theory (B3LYP and M06-2X) and compared to experimental data (
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_dedup___::0f34a85c4df9a5dfda59fa367cfe3387
https://europepmc.org/articles/PMC3731169/
https://europepmc.org/articles/PMC3731169/
Publikováno v:
ChemInform. 42
Organocatalysis has captured the imagination of a significant group of synthetic chemists. Much of the mechanistic understanding of these reactions has come from computational investigations or studies involving both experimental and complementary co
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_________::5ff62390483b79ee204a431b14372fe9
https://doi.org/10.1002/chin.201148280
https://doi.org/10.1002/chin.201148280
Publikováno v:
Chemical reviews. 111(8)
Organocatalysis has captured the imagination of a significant group of synthetic chemists. Much of the mechanistic understanding of these reactions has come from computational investigations or studies involving both experimental and complementary co
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_dedup___::638cb6402cb85bf53101f0c896300be5
https://pubmed.ncbi.nlm.nih.gov/21707120
https://pubmed.ncbi.nlm.nih.gov/21707120
Publikováno v:
Journal of molecular catalysis. A, Chemical. 324(1-2)
Computational investigation of the aldol reaction of benzaldehyde with acetone catalyzed by various proline derivatives and 2-azetidine carboxylic acid reveal the origins of stereoselectivities of these reactions. Structural differences between catal
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_dedup___::8b5d92da4346d92757dc50c1dbd80766
https://pubmed.ncbi.nlm.nih.gov/20634993
https://pubmed.ncbi.nlm.nih.gov/20634993
The asymmetric C-alkylation of chiral enamines derived from terminal epoxides and lithium 2,2,6-trialkylpiperidides has previously been shown to provide alpha-alkylated aldehydes by intermolecular nucleophilic substitution in good levels of asymmetri
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_dedup___::e300e186acdb0b341815c59f0d1f41d1
https://europepmc.org/articles/PMC3049728/
https://europepmc.org/articles/PMC3049728/
Autor:
Franziska Schoenebeck, Osvaldo Gutierrez, Kendall N. Houk, Joann M. Um, David W. C. MacMillan
The intramolecular alpha-arylation of aldehydes via organo-SOMO catalysis was investigated using density functional theory (B3LYP and M06-2X functionals). The geometries, spin densities, Mulliken charges, and molecular orbitals of the reacting enamin
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_dedup___::abe31f11602a596cf8b63797ac22fb3f
https://europepmc.org/articles/PMC2862978/
https://europepmc.org/articles/PMC2862978/