Efficient Regioselective Synthesis of 6-Amino-5-benzoyl-1-Substituted 2(1H)-Pyridinones

First atroposelective Chan-Lam coupling for the synthesis of C-N linked biaryls

The first atroposelective Chan-Lam coupling for the synthesis of C-N axial enantiomers is reported with good yields and ee. MnO2 additive is crucial for the success of the coupling. The longstanding problem of the lack of enantioselective synthesis to make chiral C-N linked atropisomers is solved.

Enantioselective Synthesis of N-N Amide-Pyrrole Atropisomers via Paal-Knorr Reaction

The catalytic asymmetric construction of monoheteroaryl N-N axially chiral compounds and chiral five-membered aryl-based scaffolds remains challenging. Herein, we present a highly efficient enantioselective synthesis of monoheteroaryl N-N atropisomers via an asymmetric Paal-Knorr reaction, affording a diverse array of N-N amide-pyrrole atropisomers with excellent enantioselectivities. Gram-scale synthesis and post-transformations of the product demonstrated the synthesis utility of this method. Racemization experiments confirmed the configurational stability of these N-N axially chiral products. This study not only provides the first de novo cyclization example for accessing an asymmetric monoheteroaryl N-N scaffold but also offers a new member of the N-N atropisomer family with potential synthetic and medicinal applications.

Copper Catalyzed Intramolecular N-Arylation of Ketene Aminals at Room Temperature: Synthesis of 2-Amino-3-cyanoindoles

Various 2-amino-3-cyanoindoles are synthesized through copper catalyzed intramolecular N-arylations of ketene aminals at room temperature for the first time with 60-99% yields within 0.1-2 h. Controlled regioselective N-arylations of unsymmetrical ketene aminals are also studied. Further, a new double heteroannulation approach is demonstrated for the synthesis of 11-aminoindolo[2,3- b]quinolines from acyclic and nonheterocyclic precursors.

Stable C-N axial chirality in 1-aryluracil scaffold and differences in in vitro metabolic clearance between atropisomers of PDE4 inhibitor

We report herein the stable C-N axial chirality in a 1-phenyl-6-aminouracil scaffold owing to the presence of various functional groups at the ortho-position of the N(1)-phenyl group. Racemic 1-phenyl-6-aminouracils were first separated by chiral HPLC or converting them to the corresponding diastereomers using a chiral resolving agent. We then determined the rotational barrier of each atropisomer by a thermal racemization method and found that these compounds have rotational barriers similar to other C-N axially chiral biaryls. In addition, there was a good correlation between the rotational barriers and van der Waals radii of an ortho-substituent of the N(1)-phenyl group. To explore the possibility of the chiral 1-phenyl-6-aminouracil scaffold as a drug lead, we synthesized both atropisomers as phosphodiesterase-4 inhibitors 10. The atropisomers showed significantly different metabolic stabilities while their PDE4 inhibitory activities were somewhat similar. This finding demonstrates the potential utility of stable C-N bond atropisomers in the development of chiral drugs.

Synthesis and evaluation of the antitumor activity of highly functionalised pyridin-2-ones and pyrimidin-4-ones

The methods for selective synthesis of two novel types of compounds including pyridin-2-ones 3 and pyrimidin-4-ones 4 were developed. The antitumor bioactivity screening showed that certain compounds had potent antitumor activity.

Synthesis of bicyclic 2-pyridones by regioselective annulations of heterocyclic ketene aminals with anhydrides

An efficient strategy for the synthesis of substituted bicyclic 2-pyridones is developed. The proposed approach is based on the regioselective N-acylation of heterocyclic ketene aminals (HKAs) with methacrylic anhydride or crotonic anhydride.

A catalyst-free multicomponent domino sequence for the diastereoselective synthesis of (E)-3-[2-arylcarbonyl-3-(arylamino)allyl]chromen-4-ones

The three-component domino reactions of (E)-3-(dimethylamino)-1-arylprop-2-en-1-ones, 3-formylchromone and anilines under catalyst-free conditions afforded a library of novel (E)-3-(2-arylcarbonyl-3-(arylamino)allyl)-4H-chromen-4-ones in good to excellent yields and in a diastereoselective transformation. This transformation generates one C–C and one C–N bond and presumably proceeds via a reaction sequence comprising a Michael-type addition–elimination reaction, a nucleophilic attack of an enamine to a carbonyl reminiscent of one of the steps of the Bayllis–Hilman condensation, and a final deoxygenation. The deoxygenation is assumed to be induced by carbon monoxide resulting from the thermal decomposition of the dimethylformamide solvent.

Formal [4+2] annulation of enaminones and cyanomethyl sulfur ylide: one-pot access to polysubstituted pyridin-2(1H)-ones

One-pot synthesis of polysubstituted pyridin-2(1H)-ones by formal [4+2] annulation of enaminones and cyanomethyl sulfur ylide is described involving sequential nucleophilic vinylic substitution, intramolecular nucleophilic cyclization and dealkylation reactions.

Recent developments of ketene dithioacetal chemistry

Ketene dithioacetals are versatile intermediates in organic synthesis. Extensive research, since the last decade, has given rise to new prospects in their chemistry. The objective of this review is twofold: first, to highlight the new prospects in the chemistry of functionalized ketene dithioacetals, and second, to provide an intrinsic link between ketene dithioacetal groups and a variety of other functional groups, which has brought out many new facts that will assist in future designs.

1,7-Naphthyridine 1-oxides as novel potent and selective inhibitors of p38 mitogen activated protein kinase

The design, synthesis, and ability to inhibit p38α MAP kinase by a novel series of naphthyridine N-oxides will be described. Some of these compounds showed a significant reduction in the LPS-induced TNFα production in human whole blood. Structure-activity relationship studies revealed that N-oxide oxygen was essential for activity and was probably a determinant factor for its marked selectivity against other related kinases. After an extensive SAR exercise, several compounds from this series were identified as very potent p38α inhibitors. In vivo efficacy of some derivatives was demonstrated to reduce TNFα levels in an acute murine model of inflammation (ED(50) = 0.5 mg/kg in LPS-induced TNFα production when dosed orally 1.5 h prior to LPS administration). The oral efficacy was further demonstrated in a chronic model of adjuvant arthritis in rats with established disease when administered orally (ED(50) < 1 mg/kg).

A Facile Method for the Synthesis of Oxoketene-N,S- and -N,N-acetals from Reactions of Amino Compounds

2-Aroyl-3,3-bis(alkylsulfanyl)acrylaldehydes reacted with various primary amines, namely, o-phenylenediamine, ethylenediamine, and anilines to produce functionalized oxoketene-N,S-acetals and N,N-acetals in good yields. Imidazolo derivatives synthesized with o-phenylenediamine and ethylenediamine containing a formyl group could act as valuable starting materials for a variety of substituted heterocyclic compounds.

3,5-Dinitro-benzyl methane-sulfonate

The title compound, C(8)H(8)N(2)O(7)S, an inter-mediate in the synthesis of N,N-bis-(2-hydroxy-ethyl)-3,5-dinitro-aniline, exists as a discrete mol-ecule; the nitro groups are twisted with respect to the aromatic system [dihedral angles = 17.0 (1) and 26.3 (1)°].