RÉSUMÉ
An efficient Rh(II)-catalyzed highly selective N2-arylation of benzotriazole, indazole, and 1,2,3 triazole is developed using diazonaphthoquinone. The developed protocol is extended with a wide scope. In addition, late-stage arylation of these scaffolds tethered with bioactive molecules is explored. Control experiments and DFT calculations reveal that the reaction proceeds presumably via nucleophilic addition of the N2 (of the 1H tautomer) center to quinoid-carbene followed by a 1,5-H shift.
RÉSUMÉ
A Rh(II)-catalyzed simple and efficient synthesis of N-arylated 2-pyridone derivatives is described using 2-oxypyridine and diazonaphthoquinone as coupling partners. The reaction proceeds through the insertion of the nitrogen atom of the 2-oxypyridine derivative into quinoid carbene and subsequent 1,6-benzoyl migratory rearrangement. The reaction is broadened with sufficient scope and has the potential to offer axially chiral N-arylated 2-pyridone derivatives under suitable asymmetric conditions.
RÉSUMÉ
An efficient and straightforward method was developed for the synthesis of heterobiaryls using easily available N-oxides and diazonaphthoquinones under cheap Cu(II) catalysis. The developed method offered QUINOX and related congeners in a simple manner. A wide scope of important heterobiaryls was achieved with high site selectivity. The synthesized naphthols were transformed into the privileged related P,N ligands. Suitable resolution methods can directly afford the corresponding axially chiral heterobiaryls.
RÉSUMÉ
Substituted 2-pyridone is one of the most frequent scaffolds among nitrogen-containing bioactive natural products, pharmaceuticals and organic materials. Besides the classical syntheses to construct this class of molecules, retrosynthetically more straightforward approaches based on transition metal catalysed C-H bond functionalizations have been explored recently. In this review, we have summarized the recent progress in the direct transition metal catalysed construction of substituted 2-pyridone scaffolds via site-selective C-H bond functionalizations.
RÉSUMÉ
2-Pyridone is a ubiquitous motif in natural products, drug molecules, ligands in catalysis and organic materials. There is a necessity of direct step-economic methods for the construction of 2-pyridone based molecules. Strategically, the primary developments have led to the C3-functionalizations due to the inherent reactivity of this center. Despite this, many elegant transition metal-catalysed methods have been established to introduce versatile functional groups at the C4, C5 and C6-position via direct C-H bond functionalizations. This minireview focuses on the categorized introduction of different functional groups at the 2-pyridone scaffolds beyond C3-selectivity and discusses substrate scope, limitations and plausible mechanistic details.
