Copper catalyzed CN bond formation/C–H activation: synthesis of aryl 4H-3,1-benzoxazin-4-ones

Pd-Catalyzed Carbonylative Synthesis of 4H-Benzo[d][1,3]Oxazin-4-Ones Using Benzene-1,3,5-Triyl Triformate as the CO Source

A facile synthesis of 4H-benzo[d][1,3]oxazin-4-one derivatives by Pd-catalyzed carbonylative cross-coupling between N-(ortho-bromoaryl)amides and benzene-1,3,5-triyl triformate (TFBen) was developed. This procedure does not require the toxic and flammable gas CO as the carbonyl source and tolerates a wide scope of functional groups. Remarkably, 4H-benzo[d][1,3]oxazin-4-ones incorporated to natural products and drugs can be constructed by this method.

Recyclable Heterogeneous Palladium-Catalyzed Cyclocarbonylation of 2-Iodoanilines with Acyl Chlorides in the Biomass-Derived Solvent 2-Methyltetrahydrofuran

A highly efficient, green palladium-catalyzed cyclocarbonylation of 2-iodoanilines with acyl chlorides has been developed that proceeds smoothly in a biomass-derived solvent 2-methyltetrahydrofuran with N,N-diisopropylethylamine as base at 100 °C under 20 bar of carbon monoxide using an 2-aminoethylamino-modified MCM-41-anchored palladium acetate complex [2N-MCM-41-Pd(OAc)₂] as a heterogeneous catalyst, yielding a wide variety of 2-substituted 4H-3,1-benzoxazin-4-one derivatives in good to excellent yields. This supported palladium catalyst could be facilely obtained by a two-step procedure from easily available starting materials and readily recovered via a simple filtration process and recycled at least 8 times without any apparent decrease in catalytic efficiency. The developed methodology not only avoids the use of toxic solvents such as tetrahydrofuran and dimethylformamide but also solves the basic problem of expensive palladium catalyst recovery and reuse and prevents effectively palladium contamination of the desired product.

Base-promoted [3 + 3] cyclization of cyclopropenones and cyclopropenethiones with amides for the synthesis of 6H-1,3-oxazin-6-ones and 6H-1,3-thiazin-6-ones

A facile synthesis of 6H-1,3-oxazin-6-ones and 6H-1,3-thiazin-6-ones has been achieved in the base-promoted [3 + 3] cyclization of cyclopropenones and cyclopropenethiones with amides.

Spectroscopic investigation of 2-(4-benzoyl-1,5-diphenyl-1H-pyrazol-3-yl)-4H-naphto[2,3-d][1,3]oxazin-4-one molecule

In this present study, the experimental and theoretical vibrational frequencies of an important pharmacological molecule 2-(4-benzoyl-1,5-diphenyl-1[Formula: see text]-pyrazol-3-yl)-4[Formula: see text]-naphto[2,3-[Formula: see text]][1,3]oxazin-4-one have been researched. The experimental FT-IR and laser-Raman spectra of the title compound have been taken in the region (4000–400[Formula: see text]cm[Formula: see text]) and (4000–100[Formula: see text]cm[Formula: see text]), respectively. The vibrational modes and optimized structure parameters have been computed by using DFT/B3LYP methods with 6-311[Formula: see text]G(d,p) basis set. In our calculations, Gaussian 09W software program has been used. Assignments of theoretical vibrations have been obtained by potential energy distribution analysis using VEDA 4 software program. This program is important because it performs assignments with 10% precision. We have obtained a fairly good agreement between experimental and theoretically obtained results, and these results have supported the literature. Additionally, we have examined the highest occupied molecular orbital and the lowest unoccupied molecular orbital energies, the other related molecular energy values, nuclear magnetic resonance ([Formula: see text]C and 1H-proton) chemical shifts, and UV–Vis wavelengths (electronic absorption wavelengths of the title compound) by using the mentioned calculation level. The nonlinear optical properties of the title compound have also been determined by using DFT/B3LYP/6-311[Formula: see text]G(d,p) level.

Electronic halocyclization and radical haloazidation of benzene-linked 1,7-dienes for the synthesis of functionalized 3,1-benzoxazines

Electronic halocyclization and radical haloazidation of benzene-linked 1,7-dienes by using TMSN₃ as an azidyl source and NBS as a halogen source has been disclosed in this paper, producing a series of functionalized 3,1-benzoxazines in moderate to good yields.

Selective Oxidative Decarbonylative Cleavage of Unstrained C(sp(3))-C(sp(2)) Bond: Synthesis of Substituted Benzoxazinones

A transition metal (TM)-free practical synthesis of biologically relevant benzoxazinones has been established via a selective oxidative decarbonylative cleavage of an unstrained C(sp(3))-C(sp(2)) bond employing iodine, sodium bicarbonate, and (t)butyl hydroperoxide in DMSO at 95 °C. Control experiments and Density Functional Theory (DFT) calculations suggest that the reaction involves a [1,5]H shift and extrusion of CO gas as the key steps. The extrusion of CO has also been established using PMA-PdCl2.

One-pot three-component synthesis of quinazolines via a copper-catalysed oxidative amination reaction

A copper-catalysed three-component reaction for constructing a series of quinazoline derivatives has been developed.

Synthesis of functionalized benzoxazines by copper-catalyzed C(sp3)–H bond functionalization of acetonitrile with olefinic amides

A Cu-mediated/catalyzed oxycyanomethylation reaction of olefinic amides with acetonitrile was developed for the synthesis of important benzoxazine derivatives.