Results 11 to 20 of about 8,448 (224)

Studies on the Synthesis of DMAP Derivatives by Diastereoselective Ugi Reactions

Molecules, 2011
Diastereoselective Ugi reactions of DMAP-based aldehydes with α-amino acids and tert-butyl isocyanide were examined. The reactions of 4-(dimethylamino)-2-pyridine-carboxaldehyde with various α-amino acids afforded 2-substituted DMAP derivatives with low ...
Koichi Mitsudo, Seiji Suga, Hiroki Mandai, Shunsuke Irie   +3 more
doaj   +1 more source

Diastereoselective Cascade Cyclization of Diazoimides with Alkylidene Pyrazolones for Preparation of Pyrazole-Fused Oxa-Bridged Oxazocines

Molecules, 2023
Under the catalysis of Rh2(OAc)4 (10 mol%) and binapbisphosphine ligand (±)-L3 (20 mol%) in DCE at 80 °C, the cascade cyclization of diazoimides with alkylidenepyrazolones underwent stereoselectively (dr > 20:1), affording pyrazole-fused oxa-bridged ...
Kuo Wang, Yue Zhang, Lu-Yu Cai, Xiu-Qing Song, Chen Wang, Jia-Rui Zhang, Yi-Fan Pan, Hong-Wu Zhao   +7 more
doaj   +1 more source

New Advances in the Synthetic Application of Enantiomeric 1-Phenylethylamine (α-PEA): Privileged Chiral Inducer and Auxiliary

Molecules, 2020
New developments in the synthesis, resolution, and synthetic applications of chiral 1-phenylethylamine (α-PEA) reported in the last decade have been reviewed. In particular, improvements in the synthesis of α-PEA and its derivatives and chiral resolution,
Marzena Wosińska-Hrydczuk, Jacek Skarżewski   +1 more
doaj   +1 more source

Highly stereocontrolled total synthesis of racemic codonopsinol B through isoxazolidine-4,5-diol vinylation

Beilstein Journal of Organic Chemistry, 2021
A new highly diastereoselective synthesis of the polyhydroxylated pyrrolidine alkaloid (±)-codonopsinol B and its N-nor-methyl analogue, starting from achiral materials, is presented.
Lukáš Ďurina, Anna Ďurinová, František Trejtnar, Ľuboš Janotka, Lucia Messingerová, Jana Doháňošová, Ján Moncol, Róbert Fischer   +7 more
doaj   +1 more source

Diastereoselective Three-Component Reactions of Chiral Nickel(II) Glycinate for Convenient Synthesis of Novel α-Amino-β-Substituted-γ,γ-Disubstituted Butyric Acids

Molecules, 2014
The convenient, high yielding and diastereoselective synthesis of α-amino-β-substituted-γ,γ-disubstituted butyric acid derivatives was carried out by a three-component tandem reaction of a chiral equivalent of nucleophilic glycine.
Rui Zhou, Li Guo, Cheng Peng, Gu He, Liang Ouyang, Wei Huang   +5 more
doaj   +1 more source

The role of an aromatic group in remote chiral induction during conjugate addition of α-sulfonylallylic carbanions to ethyl crotonate

Beilstein Journal of Organic Chemistry, 2008
The impact of a remote aromatic nucleus on the stereochemical outcome of the conjugate addition of α-sulfonylallylic carbanions to an α,β-unsaturated ester was investigated.
Shlomo Levinger, Ranjeet Nair, Alfred Hassner   +2 more
doaj   +1 more source

Highly Diastereoselective Construction of Carbon– Heteroatom Quaternary Stereogenic Centers in the Synthesis of Analogs of Bioactive Compounds: From Monofluorinated Epoxyalkylphosphonates to α-Fluoro-, β-, or γ-Amino Alcohol Derivatives of Alkylphosphonates

Frontiers in Chemistry, 2021
The synthesis of the stable surrogates of an important amino acid (R)-4-amino-3-hydroxybutyric acid (GABOB) such as substituted hydroxy aminophosphonic acids bearing a quaternary stereogenic center is presented.
Magdalena Rapp, Klaudia Margas-Musielak, Patrycja Kaczmarek, Agnieszka Witkowska, Tomasz Cytlak, Tomasz Cytlak, Tomasz Siodła, Henryk Koroniak   +7 more
doaj   +1 more source

Novel Polycondensed Partly Saturated β-Carbolines Including Ferrocene Derivatives: Synthesis, DFT-Supported Structural Analysis, Mechanism of Some Diastereoselective Transformations and a Preliminary Study of their In Vitro Antiproliferative Effects

Molecules, 2020
Use of a Pictet-Spengler reaction of tryptamine and l-tryptophan methyl ester and subsequent reduction of the nitro group followed by further cyclocondensation with aryl aldehydes and formyl–substituted carboxylic acids, including ferrocene-based ...
Kinga Judit Fodor, Dániel Hutai, Tamás Jernei, Angéla Takács, Zsófia Szász, Máté Sulyok-Eiler, Veronika Harmat, Rita Oláh Szabó, Gitta Schlosser, Ferenc Hudecz, László Kőhidai, Antal Csámpai   +11 more
doaj   +1 more source

Synthesis of Pyrrole Phosphonate Esters: Emphasis on Pyrrole NH Acids and Dialkylacetylenic Esters Substitution [PDF]

Iranian Journal of Chemistry & Chemical Engineering, 2008
Reaction of dialkyl acetylenedicarboxylates 1a-c andpyrrole derivatives 2a-e in the presence of triphenylphosphite (TPP) was investigated and the effect of the pyrrole substitution was established.
Malek Taher Maghsoodlou, Faramarz Rostami Charati, Sayed Mostafa Habibi Khorassani, Maryam Khosroshahrodi   +3 more
doaj  

A Novel Class of “Super‐Strained” Spiro Heterocycles: Gateway to 1‐Azaspiro[3.3]heptane Derivatives, and Biological Validation

Angewandte Chemie, EarlyView.
A new class of “super‐strained” spiro heterocycles—spirocyclic 1‐azabicyclo[1.1.0]butanes—was synthesized via insertion of cyclobutane‐, oxetane‐, and azetidine‐containing sulfonium reagents into substituted azirines. The stability of this new class of compounds was studied.
Philipp Natho, Annarita Vicenti, Marco Colella, Francesco Pasca, Giuseppe Romanazzi, Mauro Niso, Carmen Abate, Ernesto Mesto, Emanuela Schingaro, Renzo Luisi   +9 more
wiley   +2 more sources