Results 151 to 160 of about 3,272,143 (363)

Enantioselective Total Synthesis of (−)‐Blennolide A

Chemistry – A European Journal, 2013
AbstractBlennolide A can be synthesized through an enantioselective domino‐Wacker/carbonylation/methoxylation reaction of 7 a with 96 % ee and an enantioselective Wacker oxidation of 7 b with 89 % ee. Further transformations led to the α,β‐unsaturated ester (E)‐17, which was subjected to a highly selective Michael addition, introducing a methyl group ...
Tietze, Lutz Friedjan, Ma, Ling, Reiner, Johannes R., Jackenkroll, Stefan, Heidemann, Sven   +4 more
openaire   +4 more sources

Asymmetric Aziridination of Allylic Carbamates Using Ion‐Paired Rhodium Complexes and Extrapolation to C─H Amination of Phenethyl Carbamates

Angewandte Chemie, EarlyView.
Aziridination of alkenes is an important route to chiral nitrogen‐containing building blocks. We report that carbamate‐functionalized allylic alcohols undergo highly enantioselective aziridination using achiral dimeric Rh complexes ion‐paired with cinchona alkaloid‐derived chiral cations.
Arthur R. Lit, Shotaro Takano, Christian Zachau, Ioana Băltărețu, Robert J. Phipps   +4 more
wiley   +2 more sources

Enantioselective Synthesis of the C(1)-C(6?) Subunit of Zaragozic Acid C

Journal of the Brazilian Chemical Society, 1998
Preparation of the C(1)-C(6?) subunit of Zaragozic acid C is described. The C(5?) methyl-bearing stereocenter is installed by rapid, regioselective opening of a phenylcyclopropyl carbinol with Pearlman?s catalyst (1 atm H2) in 2% triflic acid/methanol.
Carreira Erick M., Ledford Brian E.
doaj  

Applications of Nanozymes in Chiral-Molecule Recognition through Electrochemical and Ultraviolet–Visible Analysis

Molecules
Chiral molecules have similar physicochemical properties, which are different in terms of physiological activities and toxicities, rendering their differentiation and recognition highly significant. Nanozymes, which are nanomaterials with inherent enzyme-
Jing-Jing Dai, Guo-Ying Chen, Lei Xu, Huan Zhu, Feng-Qing Yang   +4 more
doaj   +1 more source

Identification of Ti(salen) Complexes for Efficient Catalysis in Single‐Electron Steps by Cyclic Voltammetry

Angewandte Chemie, EarlyView.
Catalyst screening without catalysis. By combining cyclic voltammetry and DFT calculations we were able to identify a highly active catalyst for the radical arylation of epoxides without performing any reactions. The prevention of chloride binding that leads to catalyst inhibition was established as the key structural feature.
Niklas Schmickler, Sergei Gerber, Lennart Hanz, Stefan Grimme, Zheng‐Wang Qu, Inke Siewert, Andreas Gansäuer   +6 more
wiley   +2 more sources

Asymmetric Intramolecular α‐Arylation of Polar Amino Acids Bearing β‐Leaving Groups

Angewandte Chemie, EarlyView.
Use of enolate chemistry to functionalise amino acids with β‐heteroatom side‐chains (serine, cysteine, threonine, etc.) is hampered by β‐elimination. We show that α‐arylation can be achieved by incorporating the side chain into a saturated heterocycle, making the unwanted elimination a disfavoured 5‐endo‐trig reaction.
Ömer Taspinar, Daniel J. Leonard, Nathan Picois, Cornelia Göcke, Matej Žabka, Hazel A. Sparkes, Jonathan Clayden   +6 more
wiley   +2 more sources

Organocatalytic atroposelective construction of axially chiral arylquinones

Nature Communications, 2019
Axially chiral compounds have widespread use in asymmetric catalysis. Here, the authors disclose a highly enantioselective synthesis of axially chiral o-naphthoquinones by chiral phosphoric acid catalysis and central-to-axial chirality conversion.
Shuai Zhu, Ye-Hui Chen, Yong-Bin Wang, Peiyuan Yu, Shao-Yu Li, Shao-Hua Xiang, Jun-Qi Wang, Jian Xiao, Bin Tan   +8 more
doaj   +1 more source

A formal and enantioselective synthesis of (−)-serricornin, the sex pheromone of the cigarette beetle (lasioderma serricorne F.) [PDF]

, 1994
J. Tércio, B. Ferreira, Jacqueline Aparecida Marques, Joseph P. Marino   +3 more
openalex   +1 more source

Shaping of a Reactive Manganese Catalyst Enables Access to Polyfunctionalized Cyclohexanes via Enantioselective C(sp3)─H Bond Oxidation of 1,3‐meso Diethers

Angewandte Chemie, EarlyView.
Structural shaping of a highly reactive chiral Mn‐oxo species translates into exceptionally enantioselective C─H oxidation catalyst of cyclohexyl 1,3‐meso diethers (up to >99% ee) leading to polyfunctionalized cyclohexanes. Abstract Chiral polyoxygenated cyclohexanes are valuable constituents of biologically relevant products.
Andrea Palone, Arnau Call, Aleria Garcia‐Roca, Josep M. Luis, Matthew S. Sigman, Massimo Bietti, Cristina Nevado, Miquel Costas   +7 more
wiley   +2 more sources

A carbohydrate approach for the formal total synthesis of (−)-aspergillide C

Beilstein Journal of Organic Chemistry, 2014
An enantioselective formal total synthesis of aspergillide C is accomplished using commercially available tri-O-acetyl-D-galactal employing a Ferrier-type C-glycosylation, utilizing a Trost hydrosilylation and protodesilylation as key reactions.
Pabbaraja Srihari, Namballa Hari Krishna, Ydhyam Sridhar, Ahmed Kamal   +3 more
doaj   +1 more source