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A protocol has been developed for the synthesis of six‐ and seven‐membered ring lactams fused to coumarins through a hydroaminocarbonylation reaction catalyzed by palladium. The catalytic system (PdBr2/Xantphos) provided a strategy for the synthesis of seven‐membered ring lactams with good isolated yield and regioselectivity. Control of selectivity by the substrate in the synthesis of six‐membered ring lactams was observed. Control reactions showed the importance of the hydrogen in the cyclocarbonylation reaction, and NMR data supported the role of the hydride palladium species as a catalytic precursor. A preliminary screening of the cytotoxic activity of coumarin‐fused lactams against six cancer cell lines was evaluated. The biological tests indicated that both the size of the heterocycle and presence of a substituent on the aromatic ring affected the inhibition of cell growth. [ABSTRACT FROM AUTHOR]

A series of pyridylimine ligands with variations of the substituent at the imine nitrogen were synthesized and coordinated to the [MoCl2O2] core. The novel molecular structures of the complexes were fully characterized by 1H and 13C NMR, FT‐IR, ESI, EA, and X‐ray crystallography, and their catalytic activity was studied for the epoxidation of alkenes using tert‐butyl hydroperoxide (TBHP) as the oxidant. The new complexes showed excellent catalytic activity and fine selectivity in the epoxidation reaction compared with similar homogeneous molybdenum complexes. The results demonstrated that there is a significant change in the catalytic performance, depending on the alkyl arm on the structure of the pyridilimine ligand. The catalytic results indicated that complex [MoCl2O2(L)] (L: N‐(2‐Pyridinylmethylene)‐1‐tert‐butylimine) C5 is the best catalytic precursor in the epoxidation of cyclohexene (TON: 92920 and TOF: 30974 h−1). [ABSTRACT FROM AUTHOR]

Seven‐membered ring lactones fused to coumarin scaffolds were obtained via a palladium‐catalyzed regioselective intramolecular alkoxycarbonylation under a CO atmosphere. Cyclocarbonylation of 3‐allyl‐4‐hydroxycoumarin derivatives was accessed in the absence of hydrogen gas, acidic conditions, or any other additives. The results of the control experiments revealed the importance of pKa of the substrate for initiating the reaction. [ABSTRACT FROM AUTHOR]

A versatile route has been developed for the synthesis of 2‐arylindoles using a Pd‐catalyzed tandem process. Under reductive conditions, different 2‐arylindoles were synthesized from phenylglyoxal and aniline. This synthetic methodology involves a tandem reaction of four steps with high regioselectivity. Alternatively, 2‐anilinoacetophenones intermediates also can be using to give access to the corresponding 2‐arylindoles. [ABSTRACT FROM AUTHOR]

In their Research Article, K. Almaraz and M. Amézquita-Valencia prepared a new series of six- and seven-membered ring lactam fused to coumarin core via Pd-catalyzed hydroaminocarbonylation reaction under syngas conditions. Keywords: Cyclocarbonylation; Lactam; Palladium; Regioselectivity; Medium-sized heterocycles EN Cyclocarbonylation Lactam Palladium Regioselectivity Medium-sized heterocycles 1 1 1 08/23/23 20230821 NES 230821 B The Cover Feature b , designed by Hortensia Segura, illustrates a brave little cat (the catalyst) jumping onto a garden wall, crossing a seven-membered ring lactam fused to a coumarin scaffold. Cover Feature: Pd-Catalyzed Intramolecular Hydroaminocarbonylation of 3-Allyl-4-arylaminocoumarins: Synthesis of Six- and Seven-membered Ring Lactams Fused to the Coumarin Scaffold (ChemCatChem 16/2023). [Extracted from the article]

Herein, we report a new straightforward catalytic synthesis of 2,3-disubstituted indoles from α-diketones 1 and N-substituted anilines 2 by employing a palladium(II) trifluoroacetate/1,1′-bis(diphenylphosphino)ferrocene ([Pd(tfa)2]/dppf; 1:1.5) under reductive conditions and without an external oxidant. The tandem reaction involves ketoenamine and ketoamine as intermediates and a final dehydration-annulation reaction to obtain the 2,3-disubstituted indole. New palladium hydride species, which catalyze the reaction, could not be isolated but Pd-H species were observed by NMR and IR spectroscopy and mass spectrometry (FAB+) studies. This work presents a new regioselective route with a plausible mechanism to synthesize 2,3-disubstituted indoles under reductive conditions. [ABSTRACT FROM AUTHOR]

An unprecedented C-benzylation rearrangement reaction, catalyzed by palladium, is reported. The reaction proceeds by rearrangement leading to the direct synthesis of para or ortho benzyl-substituted N-methylanilines. The product is obtained in high regioselectivity, without the need to use a ligand for the catalytic process. [ABSTRACT FROM AUTHOR]

The title compound, C(18)H(27)NO(2), crystallizes as the enamine form with Z geometry. The β-enamino-ester fragment forms a dihedral angle of 87.5 (1)° with the isopropyl-phenyl frame. The structure exhibits an intra-molecular N-H⋯O hydrogen bond. In addition, in the crystal, mol-ecules are linked by a centrosymmetric inter-molecular N-H⋯O hydrogen bond.

The title compound, C(15)H(21)NO(2), was obtained by the reaction of acetoacetate with 2,4,6-trimethyl-aniline using Mexican bentonitic clay as a catalyst. It crystallizes in the enamine form. The β-enamino ester residue is almost perpendicular to the aromatic ring [dihedral angle = 88.10 (6)°]. The mol-ecular conformation is stabilized by a strong intra-molecular N-H⋯O hydrogen bond. In addition, the N-H group forms a weak inter-molecular N-H⋯O hydrogen bond linking the mol-ecules into centrosymmetric dimers.