Results 31 to 40 of about 8,448 (224)

Organocatalytic Enantioselective Addition of Malonates to Cyclic Imines: A Short Total Synthesis of Tetraponerine T‐1

Angewandte Chemie, EarlyView.
A stereoselective functionalization method of cyclic imines under mild organocatalytic conditions was developed. Bifunctional cinchona alkaloid catalysts combined with carefully optimized reaction conditions to suppress background reactivity enabled highly enantio‐ and diastereoselective addition reactions of malonates to cyclic imines.
Frederic Kölblin, Helma Wennemers
wiley   +2 more sources

Pd‐Catalyzed Asymmetric Dearomative Heck/Tsuji‐Trost Difunctionalization of Naphthalenes

Advanced Science, EarlyView.
We have developed a palladium‐catalyzed asymmetric dearomative Heck/Tsuji‐Trost 1,4‐difunctionalization reaction of naphthalenes, affording 4‐aminospirocyclohexene oxindole products bearing two remote chiral centers. Through the effect of the newly designed chiral sulfinamide phosphine ligand with large steric hindrance, side reactions are inhibited ...
Long‐Ling Ma, Bing Xu, Junliang Zhang, Zhan‐Ming Zhang   +3 more
wiley   +1 more source

Cobalt‐Catalyzed Radical Ligand Transfer (RLT) Enables Remote‐Markovnikov Hydroamination of Alkenes

Angewandte Chemie, EarlyView.
A cobalt‐catalyzed remote‐Markovnikov 1,3‐hydroamination of allyl carboxylates proceeds through MHAT, 1,2‐radical acyloxy migration (1,2‐RAM), and radical ligand transfer (RLT) from a Co‐N intermediate, providing protected amino alcohols. ABSTRACT Amino alcohols are prevalent in pharmaceuticals, agrochemicals, and functional materials, yet ...
Arman Khosravi, Ho Martin Yuen, Seth Fremin, Nuwan A. Pannilawithana, Nol Supasueb, Yu Zhang, Peng Liu, Ming‐Yu Ngai   +7 more
wiley   +2 more sources

Diastereomeric Monomers Enable Anion‐Exchange Membranes With Controlled Local Polymer Backbone Flexibility and High Conductivity

Advanced Science, EarlyView.
Stereochemistry enables control of ion‐exchange membrane properties via local backbone flexibility without altering the polymer composition. Syn‐enriched membranes show higher water uptake and improved water‐electrolysis performance, whereas anti‐enriched membranes exhibit higher hydration efficiency and improved mechanical properties.
Si Chen, Xuchen Lyu, Triet Nguyen Dai Luong, Patric Jannasch   +3 more
wiley   +1 more source

Recent Advances in π-Stacking Interaction-Controlled Asymmetric Synthesis

Molecules
The π-stacking interaction is one of the most important intramolecular and intermolecular noncovalent interactions in organic chemistry. It plays an important role in stabilizing some structures and transition states in certain reactions via both ...
Jiaxi Xu
doaj   +1 more source

(1R/S,7aS/R)-1-Benzyl-1-[2,8-bis(trifluoromethyl)quinolin-4-yl]-hexahydro-oxazolo[3,4-a]pyridin-3-one

Molbank, 2023
An unexpected diastereoselective C-alkylation of a mefloquine derivative in up to 57% yield was the result of an attempted Williamson etherification of Boc-mefloquine.
Dawid J. Kucharski, Przemysław J. Boratyński   +1 more
doaj   +1 more source

Diastereoselective Intramolecular Cyanoamidation with Alkenes [PDF]

European Journal of Organic Chemistry, 2016
Reported herein is a diastereoselective intramolecular alkene cyanoamidation, wherein high d.r. values are imparted by chiral directing groups. Lactams with an α‐all‐carbon quaternary stereocenter are readily synthesized, which may enable access to structures frequently found in biologically active molecules and natural products.
Ashley M. Dreis, Sadie C. Otte, Matthew S. Eastwood, Elizabeth R. Alonzi, Jason T. Brethorst, Christopher J. Douglas   +5 more
openaire   +2 more sources

Hypervalent Iodine-Mediated Diastereoselective α-Acetoxylation of Cyclic Ketones

Frontiers in Chemistry, 2020
A binary hybrid system comprising a hypervalent iodine(III) reagent and BF3•OEt2 Lewis acid was found to be effective for the diastereoselective α-acetoxylation of cyclic ketones.
Jiashen Tan, Weiqin Zhu, Weiping Xu, Yaru Jing, Yaru Jing, Zhuofeng Ke, Yan Liu, Keiji Maruoka, Keiji Maruoka   +8 more
doaj   +1 more source

An effective one-pot access to polynuclear dispiroheterocyclic structures comprising pyrrolidinyloxindole and imidazothiazolotriazine moieties via a 1,3-dipolar cycloaddition strategy

Beilstein Journal of Organic Chemistry, 2016
An effective and highly regio- and diastereoselective one-pot method for the synthesis of new polynuclear dispiroheterocyclic systems with five stereogenic centers (dispiro[imidazo[4,5-e]thiazolo[3,2-b]-1,2,4-triazine-6,3′-pyrrolidine-2′,3′′-indoles ...
Alexei N. Izmest’ev, Galina A. Gazieva, Natalya V. Sigay, Sergei A. Serkov, Valentina A. Karnoukhova, Vadim V. Kachala, Alexander S. Shashkov, Igor E. Zanin, Angelina N. Kravchenko, Nina N. Makhova   +9 more
doaj   +1 more source

Diastereoselective Ugi reaction for the synthesis of unnatural amino esters

Orbital: The Electronic Journal of Chemistry, 2012
Multicomponent Reactions (MCR) are useful reactions to obtain complex products by the simple mixture of 3 or more reactants. The classic Ugi reaction (4-UCR) involves a mixture of an amine, aldehyde, isocyanide and a carboxylic acid, giving peptoides as ...
Rafael Oliveira Rocha, Milenna Milhomem Sena, Gecimar Oliveira Gomes, Carlos Kleber Z. Andrade, Márcio Weber Paixão   +4 more
doaj   +1 more source