Stereoselective synthesis of oxabicyclic pyrrolidines of medicinal relevance. Merging chemoenzymatic and catalytic methods

Two approaches to the synthesis of an oxabicyclic pyrrolidine‐6‐one are described using enzymatic resolution and gold‐mediated catalysis as key steps toward enantiopure compounds previously reported as racemic mixtures. Addition of Grignard reagents to the ketone afforded a variety of diversified tertiary alcohols of interest for their reported pharmacological...

2d

Stereoselective synthesis of oxabicyclic pyrrolidines of medicinal relevance. Merging chemoenzymatic and catalytic methods

Two approaches to the synthesis of an oxabicyclic pyrrolidine‐6‐one are described using enzymatic resolution and gold‐mediated catalysis as key steps toward enantiopure compounds previously reported as racemic mixtures. Addition of Grignard reagents to the ketone afforded a variety of diversified tertiary alcohols of interest for their reported pharmacological...

2d

Double Porphyrin Cage Compounds

The synthesis of double porphyrin cage compounds based on glycoluril is described. Through a multistep synthesis, three double cage compounds linked by spacers of variable length are obtained. The binding and conformational properties of their zinc derivatives towards the ditopic ligand dabco have been investigated into detail. The synthesis and...

2d

Studies towards Pyridine‐Based N,N,O‐Gold(III) Complexes: Synthesis, Characterization and Application

Studies on gold(III) coordination of a series of new chiral polydentate (X,)N,O‐pyridine based ligands are reported. Successful coordination afforded novel chiral N,N,O‐tridentate Au(III) complexes with the 2‐pyridyl‐6‐[(1S,2S,5R)‐neomenthol‐1‐yl]pyridine ligand (1H, 13C, 15N NMR, HRMS, IR, XRD). The chiral 2‐aryl‐6‐alkylpyridine alcohol ligands were...

2d

Two‐Step Procedure for the Synthesis of 1,2,3,4‐Tetrahydro‐quinolines

Hydroaminoalkylation reactions of ortho‐chlorostyrenes with various secondary amines deliver the linear addition products with high regioselectivity. A combination of this reaction with a subsequent intramolecular Buchwald–Hartwig amination creates a new and simple two‐step procedure that gives direct access to pharmacologically important 1,2,3,4‐tetrahydroquinolines....

2d

Cu‐TEMPO Catalyzed Dehydrogenative Friedlander Annulation/sp3 C–H Functionalization/Spiroannulation towards Spiro[indoline‐3,3'‐pyrrolizin]‐2'‐yl)‐4‐phenylquinoline‐3‐Carboxylates

The spiro[indoline‐3,3'‐pyrrolizin]‐2'‐yl)‐4‐phenylquinoline‐3‐carboxylate 6 and chimanine A analogues 7 were achieved through Cu(OAc)2/TEMPO catalyzed dehydrogenative Friedlander annulation/sp3 C–H functionalization/spiroannulation sequence in DMU‐tartaric acid. A series of spiro[indoline‐3,3'‐pyrrolizin]‐2'‐yl)‐4‐phenylquinoline‐3‐carboxylate...

2d

A Facile Synthesis of 3‐(Arylthio)imidazo[1,2‐a]pyridin‐2(3H)‐ones from 2‐Aminopyridinium Bromides and Sodium Arenesulfinates

Synthesis of 3‐(arylthio)imidazo[1,2‐a]pyridin‐2(3H)‐ols has been achieved through a catalyst‐free, one‐pot reaction of 2‐aminopyridinium bromides with sodium arenesulfinates. The tandem reaction involved intramolecular amidation followed by sulfenylation and afforded a wide range of 3‐(arylthio)imidazo[1,2‐a]pyridin‐2(3H)‐ols in moderate to excellent...

2d

Shining Light on TiIV Complexes: Exceptional Tools for Metallaphotoredox Catalysis

Metallaphotoredox catalysis is emerging as an excellent and versatile cornerstone for the development of modern synthetic methodologies. Recent examples have displayed how the redox chemistry of titanium‐based complexes can be triggered by organic and inorganic chromophores in catalytic processes activated by visible‐light, affording synthetically demanding...

2d

On the Regioselectivity of the Gould–Jacobs Reaction: Gas‐Phase Versus Solution‐Phase Thermolysis

The regioselectivity of the Gould–Jacobs reaction of (pyridyl)aminomethylenemalonates can be controlled either in favor of the kinetic (pyridopyrimidinone) or the thermodynamic (naphthyridinone) product, depending on the position of the substituent in the pyridine moiety and the applied thermolysis technique. A detailed investigation of the regioselectivity...

2d

Front Cover: Synthesis of Peptido RNAs from Unprotected Peptides and Oligoribonucleotides via Coupling in Aqueous Solution (Eur. J. Org. Chem. 45/2020)

The Front Cover shows the structure of a peptido RNA that was prepared in NMR quantities from a peptide and an oligoribonucleotide in aqueous solution, without the need for protecting groups. The two‐step protocol starts with conversion of the 5'‐terminal phosphate of the RNA to an imidazolide, followed by 1‐ethylimidazole‐catalyzed coupling at pH 8...

2d