The First Examples of Nazarov Cyclizations Leading to Annulated Pyrroles

Reactions between α-substituted unsaturated carboxylic acids 20 and N-tosylpyrroles [14, 23] in the presence of trifluoroacetic anhydride result in smooth α-acylation of the pyrrole, followed by Nazarov cyclization to give 50−80% yields of cyclopenta[b]pyrroles. The presence of an α-substituent in the unsaturated acid appears to be mandatory

Synthesis of pyrrol-pyridazyl-triazolyl-pyridines via Cu(I)-catalyzed azide-alkyne 1,3-dipolar cycloaddition reaction

<p>Conjugated alternative donor–acceptor type pyrrol-pyridazyl-triazolyl-pyridine <i>N</i>-heterocyclic systems were synthesized via Cu(I)-catalyzed azide-alkyne 1,3-dipolar cycloaddition reaction of pyrrol-pyridazylacetylene with azidopyridines.</p

Computational insights into the origin of decrease/increase in potency of <i>N</i>-CDPCB analogues toward FTO

Computational insights into the origin of decrease/increase in potency of <i>N</i>-CDPCB analogues toward FT

Synthesis of Isoxazoles via One-Pot Oxidation/Cyclization Sequence from Propargylamines

A facile strategy for the synthesis of isoxazoles has been efficaciously developed, which involves oxidation of propargylamines to the corresponding oximes followed by CuCl-mediated intramolecular cyclization of the latter. This protocol shows a straightforward way to construct a series of isoxazole cores with a wide range of functional group compatibility. Meanwhile, a gram-scale experiment and synthetic applications can be successfully operated

Total Synthesis of (+)-Aspidospermidine

A facile asymmetric total synthesis of (+)-aspidospermidine has been developed, which is accomplished in 11 steps in an overall yield of 9.6%. Key steps involve a palladium-catalyzed enantioselective decarboxylative allylation to install the quaternary carbon stereocenter and a highly efficient reductive amination–carbonyl reduction–dehydration–intramolecular conjugate addition cascade to build the cis D-ring

Copper-Catalyzed Synthesis of <i>N</i>‑Fused Quinolines via C(sp³)–H Activation-Radical Addition–Cyclization Cascade

A novel copper-catalyzed cyclization reaction for the synthesis of pyrazolo[1,5-a]quinoline, triazolo[1,5-a]quinoline, and pyrrolo[1,2-a]quinoline derivatives is described. The process is initiated by di-tert-butyl peroxide-mediated C(sp3)–H activation to generate the α-functionalized radical, which supervenes a cascade radical addition/cyclization sequence to access the N-fused quinolines in good yields with broad functional group tolerance

Construction of a Protoberberine Alkaloid Skeleton via the Palladium-Catalyzed α‑Arylation–Amide Formation Cascade

In this work, we report the strategy of one-pot synthesis of protoberberine alkaloid derivatives via palladium-catalyzed cascade α-arylation and cyclization, which can afford the target molecules in moderate to excellent isolated yields using commercially available raw materials under solvent-free conditions. This protocol provides an efficient and convenient path to multisubstituted protoberberine derivatives. In addition, it can directly afford natural alkaloids

Divergent Syntheses of Carbazole Alkaloids Clausenapin, Indizoline, Claulansine M, and Clausenaline D

We described the first total syntheses of clausenapin, indizoline, claulansine M, and a novel synthetic route to clausenaline D via divergent method. Key steps involved TFAA-mediated intramolecular acylation to construct the carbazole core and subsequent Claisen rearrangement to generate key intermediates for further elaboration to target molecules

Enantioselective Syntheses of α-Fmoc-Pbf-[2-¹³C]-l-arginine and Fmoc-[1,3-¹³C₂]-l-proline and Incorporation into the Neurotensin Receptor 1 Ligand, NT₈₋₁₃

Enantioselective syntheses of selectively labeled, orthogonally protected [2-13C]-l-arginine and [1,3-13C2]-l-proline are described from the commercially available precursors [2-13C]bromoacetic acid and potassium [13C]cyanide. Interestingly the enhanced signal assigned to C-2 in the 13C NMR spectrum of α-Fmoc-Pbf-[2-13C]-l-arginine was very broad at room temperature. The two Fmoc-labeled amino acids were used to prepare [2-13C]-Arg9 and [1,3-13C2]-Pro10 labeled ligand (NT8−13) by manual Fmoc-SPSS

Synthesis of 2‑Cyclopentenone Derivatives via Palladium-Catalyzed Intramolecular Carbonyl α‑Alkenylation

2-Cyclopentenone derivatives have been efficiently synthesized from 5-bromo-5-hexen-2-ones via palladium-catalyzed intramolecular carbonyl α-alkenylation followed by double-bond migration under mild reaction conditions