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The development of efficient synthetic procedures to access fused N, O-heterocyclic skeletons has been a pivotal research topic in organic synthesis for several years. Owing to the applications of N, O-fused heterocycles in organic synthesis, material sciences, and medicinal chemistry, significant efforts have been dedicated to design novel methods for their construction. To this end, 1,3-benzoxazin-4-ones are privileged candidates for N, O-heterocyclic molecules often found in natural products, agrochemicals, and materials science applications. In this review, we aim to summarize the existing literature on the synthesis of 1,3-benzoxazin-4-ones from 2010 onwards. Moreover, 1,3-benzoxazin-4-ones have also been identified as an excellent native directing group for the ortho-functionalization via C-H activation, which is often a strenuous task requiring pre-functionalized substrates. In the latter part of this report, we compiled several interesting examples of N-directed functionalizations of 1,3-benzoxazin-4-ones. Additionally, to emphasize biological importance, recent developments on the anticancer evaluations of benzoxazine-4-one core are included. We believe that by harnessing the methodologies discussed herein, new possibilities could be unlocked for the synthesis of fused N, O-heterocycles, leading to the development of novel biologically active compounds and functional materials. [ABSTRACT FROM AUTHOR]

The reaction of N‐(4‐methyl‐2‐pyridinyl)‐P,P‐diphenylphosphinous amide ligand 4‐Me‐C5H3N‐2‐NH(PPh2) (1) with M(CO)6 (M=Cr, Mo, W) in refluxing toluene afforded a mononuclear group VIB metal tetracarbonyls [M(CO)4{1‐κ2P,N}] (M=Cr(2), Mo(3), W(4)). Complexes 2–4 were characterized by multinuclear NMR (1H, 13C and 31P NMR) and IR spectroscopy, and their structures were also determined by single crystal X‐ray diffraction. 2 and 4 represent the first examples of structurally characterized complexes of such ligands with group 6B metal carbonyls. [ABSTRACT FROM AUTHOR]

There is a focus on using aromatic phosphinous amide as an antibacterial agent against serious multidrug resistant bacterial infections. N-(4-acetylphenyl)-P,P-diphenyl-phosphinous amide and its corresponding thioxophosphinous amide and selenoxo-phosphinous amide were synthesized and designated Ph1, Ph2, and Ph3, respectively. They were structurally identified by single crystal X-ray diffraction, multinuclear NMR spectroscopy, and elemental analysis. Because their antibacterial activities have never been examined, this study aimed to assess their antibacterial activities against both Gram-positive and Gram-negative bacteria as well as readily available standard bacterial strains. Two bacterial isolates were isolated from urine specimens collected from patients with urinary tract infections and designated CS1, and CS2. Phenotypic, biochemical, and molecular approaches were used to identify them. The antibiotic susceptibility/resistance pattern of these isolates was examined by the installed VITEK 2 system. Isolate CS1 is an aerobic Gram-positive, straight rod-shaped, spore forming, occurring singly or in a short chain, whereas isolate CS2 is an aerobic Gram-negative, coccobacilli-shaped, non-spore forming, occurring in pairs or in chains. Both isolates are positive for catalase and oxidase test. According to an examination of the 16S rRNA gene sequence, the isolates CS1 and CS2 have 98% of their similarities with Bacillus and Acinetobacter species, respectively. Isolates CS1 and CS2 are multidrug resistance species. Based on the results of the minimum inhibitory concentration, the standard bacterial strains and isolates CS1 and CS2 showed a wide range in the antibacterial capabilities of the studied phosphinous amides. In comparison to Ph2 and Ph3, Ph1 has the strongest antibacterial activity against all of the tested bacterial species. In conclusion, CS1 and CS2 isolates were identified as novel, multi-drug resistant members of the Bacillus and Acinetobacter genera, respectively. The Ph1 molecule represents a promising new generation of antibiotics with notable antibacterial efficacy against multidrug-resistant Gram-positive and Gram-negative microorganisms. [ABSTRACT FROM AUTHOR]

Herein, we describe the first consistent regiospecific reaction of isothiocyanates with a variety of substituted N-arylcyanothioformamides in a 1:1 molar ratio to generate a series of imidazolidineiminodithiones decorated with a multitude of functional groups on both aromatic rings. The reaction is carried out at room temperature using a 20 mol% catalytic amount of triethylamine with DMF as the solvent to selectively form the mentioned products with exclusive regioselectivity. The methodology features wide substrate scope, no requirement for chromatography, and good to high reaction yields. The products were isolated by simple ether/brine extraction and the structures were verified by multinuclear NMR spectroscopy and high accuracy mass measurements. The first conclusive molecular structure elucidation of the observed regioisomer was established by single-crystal X-ray diffraction analysis. Likewise, the tautomer of the N-arylcyanothioformamide reactant was proven by X-ray diffraction analysis. Density functional theory computations at the B3LYP-D4/def2-TZVP level in implicit DMF solvent were conducted to support the noted regiochemical outcome and proposed mechanism. [ABSTRACT FROM AUTHOR]

Isoselenocyanates are valuable coupling partners required for preparing key chemical intermediates and biologically active molecules in an accelerated and effective way. Likewise, (Z)‐2‐oxo‐N‐phenylpropanehydrazonoyl chlorides have been employed in numerous one‐step heteroannulation reactions to assemble the structural core of several various kinds of heterocyclic compounds. Here, we describe the inverse electron demand 1,3‐dipolar cycloaddition reaction of isoselenocyanates with a variety of substituted (Z)‐2‐oxo‐N‐phenylpropanehydrazonoyl chlorides to generate, regioselectively and stereoselectively, a series of 5‐arylimino‐1,3,4‐selenadiazole derivatives comprising a multitude of functional groups on both aryl rings. The synthetic method features gentle room‐temperature conditions, wide substrate scope, and good to high reaction yields. The selenadiazoles were separated by gravity filtration in all instances and chemical structures were validated by multinuclear NMR spectroscopy and high accuracy mass spectral measurements. First conclusive molecular structure elucidation of the observed 5‐arylimino‐selenadiazole regioisomer was verified by single‐crystal X‐ray diffraction analysis. Crystal‐structure measurement was successfully carried out on (Z)‐1‐(4‐(4‐iodophenyl)‐5‐(p‐tolylimino)‐4,5‐dihydro‐1,3,4‐selenadiazol‐2‐yl)ethan‐1‐one and (Z)‐1‐(5‐((4‐methoxyphenyl)imino)‐4‐(4‐(methylthio)phenyl)‐4,5‐dihydro‐1,3,4‐selenadiazol‐2‐yl)ethan‐1‐one. Likewise, the (Z)‐geometry of the hydrazonoyl chloride reactant was proven by X‐ray diffraction studies. As representative examples, crystal‐structure determination was carried out on (Z)‐2‐oxo‐N‐phenylpropanehydrazonoyl chloride and (Z)‐N‐(3,5‐bis(trifluoromethyl)phenyl)‐2‐oxopropanehydrazonoyl chloride. Density functional theory calculations at the B3LYP‐D4/def2‐TZVP level were conducted to support the noted experimental findings and suggested mechanism. [ABSTRACT FROM AUTHOR]

The reaction of C10H7‐1‐N(PPh2)2 (1) with two equivalents of CuI in acetonitrile resulted in the formation of octahedron Cu4I4[1]2 complex (2). The crystal structure of 2 showed it adopted a rare octahedral arrangement. The rectangular Cu4 plane is μ4‐capped by two of the iodides and is placed in axial positions above and below the Cu4‐plane form an octahedron, whereas the other two iodides are bonded to two copper atoms in a μ2‐fashion. The luminescence of complex 2 arises from a triplet halide‐to‐ligand charge transfer (3XLCT) excited state and 3CC (Cu4I4 cluster‐centered) excited state are not involved in the luminescence by the rigid bidentate ligand 1 in spite of the short CuI–CuI bond length. Complex 2 was identified and characterized by multinuclear NMR (1H, 13C, 31P NMR) and IR spectroscopy. Crystal structure determinations of 1 and 2 were carried out. [ABSTRACT FROM AUTHOR]

The reaction of p-acetylaniline with chlorodiphenylphosphine afforded the new ligand (p-CH3CO)C6H4N(H)PPh2 (1) in good yield. Monooxidized thioxo (p-CH3CO)C6H4N(H)P(S)Ph2 (2) and selenoxo (p-CH3CO)C6H4N(H)P(Se)Ph2 (3) were synthesized by the reaction of 1 with elemental sulfur or grey selenium. Compounds 1-3 were identified and characterized by multinuclear NMR spectroscopy (¹H, 13C, 31P, 77Se NMR) and elemental analysis. Compounds 2 and 3 were structurally characterized by single crystal X-ray diffraction which showed that the p-acetyl substituent on the aniline aromatic ring has a profound influence on the elongation of the P-N bond distance compared to several structurally characterized analogues found in literature. As such, subsequent reactions involving the P-N bond (i.e. insertion reactions) may be influenced in a favorable manner and proceed with ease. [ABSTRACT FROM AUTHOR]

Oxidation of N, N-bis(diphenylphosphanyl)naphthalen-1-amine ( 1) with elemental sulfur or gray selenium (1:1 molar ratio) gave the corresponding monosulfide and monoselenide bis(phosphanyl)amine ligands C10H7-1-N(P( E)Ph2)(PPh2) [ E = S ( 2), Se ( 3)], respectively. Reactions of 2 and 3 with MCl2(cod) ( M = Pd, Pt) afforded [ MCl2{ 2-κ2 P,S}] [ M = Pd( 4), Pt( 5)] and [ MCl2{ 3-κ2 P,Se}] [ M = Pd( 6), Pt( 7)], respectively. In contrast, reactions of the same ligands with NiCl2(PPh3)2 resulted in deselenization and desulfurization, producing complex 8 with the formula [NiCl2{1-κ2 P,P}]. Ligands 2 and 3, as well as their complexes 4- 7 and 8 were identified and characterized by multinuclear NMR (1H, 13C, 31P, and 77Se NMR) spectroscopy, elemental analysis, and IR spectroscopy. Additionally, the molecular structure of 8 was obtained. [ABSTRACT FROM AUTHOR]

Reactions of monooxidized thioyl and selenoyl bis(phosphanyl)amine ligands C10H7-1-N(P( E)Ph2)(PPh2) [ E = S ( 1), Se ( 2)] with Mo(CO)4(pip)2 and W(CO)4(cod) afforded the complexes [ M(CO)4{ 1-κ2 P,S}] [ M = Mo ( 3), W ( 4)] and [ M(CO)4{ 2-κ2 P,Se}] [ M = Mo ( 5), W ( 6)]. Complexes 3- 6 were characterized by multinuclear NMR (1H, 13C, 31P, and 77Se NMR) and IR spectroscopy. Crystal-structure determinations were carried out on 3, 5, and 6, which represent the first examples of structurally characterized complexes of such ligands with group-6 metal carbonyls. [ABSTRACT FROM AUTHOR]

The reaction of N, N-bis(diphenylphosphino)naphthalen-1-amine ( 1) with [M(CO)6] (M=Cr, Mo, W; 1 : 1 molar ratio) afforded cis-[M(CO)4( 1)] 2 (M=Cr), 3 (M=Mo), and 4 (M=W). Compounds 2- 4 were identified and characterized by elemental analysis and multinuclear NMR (1H-, 13C-, and 31P-NMR) and IR spectroscopy. A crystal-structure determination of complex 3 was carried out. [ABSTRACT FROM AUTHOR]

The reaction of N, N-bis(diphenylphosphino)naphthalen-1-amine ( 1) with [M(CO)6] (M=Cr, Mo, W; 1 : 1 molar ratio) afforded cis-[M(CO)4( 1)] 2 (M=Cr), 3 (M=Mo), and 4 (M=W). Compounds 2- 4 were identified and characterized by elemental analysis and multinuclear NMR (1H-, 13C-, and 31P-NMR) and IR spectroscopy. A crystal-structure determination of complex 3 was carried out. [ABSTRACT FROM AUTHOR]

Abstract: The aminoalcohols 1-HOCR2-2-NMe2C6H4 [R=Ph (1), R=C6H11 (2)] and 1-HOCPh2CH2-2-NMe2C6H4 (3) react with ZnCl2 in tetrahydrofuran to give the alcohol adducts [ZnCl2(THF){1-HOCR2-2-NMe2C6H4}] [R=Ph (4), R=C6H11 (5)] and [ZnCl2(THF){1-HOCPh2CH2-2-NMe2C6H4}] (6). The complexes 4–6 were characterized by 1H and 13C NMR spectroscopy, and 5 was also structurally characterized by X-ray crystallography. [Copyright &y& Elsevier]

Abstract: BEt2(OSO2CH3) was treated with 1-HOCPh2-2-NMe2C6H4 (1) in the presence of acetic acid to give a red oily residue, which was separated by column chromatography into the two products [1-HOCPh2-2-NHMe2C6H4][MeSO3]·MeSO3H (2) and the known compound (BEt)2(μ-O)(μ-O,O′-O2CCH3)2 (3). Compound 2 was prepared independently from 1 and methylsulfonic acid. Compound 2 was characterized spectroscopically (NMR, IR) and by crystal structure determination. The latter shows the association of two ions and one molecule [1-HOCPh2-2-NHMe2C6H4]+, [MeSO3]− and MeSO3H by hydrogen bonding. [Copyright &y& Elsevier]

Isoselenocyanates are valuable coupling partners required for preparing key chemical intermediates and biologically active molecules in an accelerated and effective way. Likewise, (Z)-2-oxo-N-phenylpropanehydrazonoyl chlorides have been employed in numerous one-step heteroannulation reactions to assemble the structural core of several various kinds of heterocyclic compounds. Here, we describe the inverse electron demand 1,3-dipolar cycloaddition reaction of isoselenocyanates with a variety of substituted (Z)-2-oxo-N-phenylpropanehydrazonoyl chlorides to generate, regioselectively and stereoselectively, a series of 5-arylimino-1,3,4-selenadiazole derivatives comprising a multitude of functional groups on both aryl rings. The synthetic method features gentle room-temperature conditions, wide substrate scope, and good to high reaction yields. The selenadiazoles were separated by gravity filtration in all instances and chemical structures were validated by multinuclear NMR spectroscopy and high accuracy mass spectral measurements. First conclusive molecular structure elucidation of the observed 5-arylimino-selenadiazole regioisomer was verified by single-crystal X-ray diffraction analysis. Crystal-structure measurement was successfully carried out on (Z)-1-(4-(4-iodophenyl)-5-(p-tolylimino)-4,5-dihydro-1,3,4-selenadiazol-2-yl)ethan-1-one and (Z)-1-(5-((4-methoxyphenyl)imino)-4-(4-(methylthio)phenyl)-4,5-dihydro-1,3,4-selenadiazol-2-yl)ethan-1-one. Likewise, the (Z)-geometry of the hydrazonoyl chloride reactant was proven by X-ray diffraction studies. As representative examples, crystal-structure determination was carried out on (Z)-2-oxo-N-phenylpropanehydrazonoyl chloride and (Z)-N-(3,5-bis(trifluoromethyl)phenyl)-2-oxopropanehydrazonoyl chloride. Density functional theory calculations at the B3LYP-D4/def2-TZVP level were conducted to support the noted experimental findings and suggested mechanism., (© 2023 Wiley-VCH GmbH.)

The title compound, C23H24O3, was obtained in a one-step (60% yield) synthesis from 1,1,1-tris(hydroxymethyl)ethane. It features a tripodal ligand capable of complexing metal centres. One of the three conformations involving the methyl group, the central C-C bond and the phenoxy substituents is antiperiplanar while the two others are synclinal [the corresponding C-C-C-O torsion angles are -174.6 (1), -53.2 (2) and -47.3 (2)°]. In the crystal, C-H⋯O inter-actions link the molecules into [010] chains.