One-Pot Synthesis of 1-Thia-4-azaspiro[4.4/5]alkan-3-ones via Schiff Base: Design, Synthesis, and Apoptotic Antiproliferative Properties of Dual EGFR/BRAFV600E Inhibitors

In this investigation, novel 4-((quinolin-4-yl)amino)-thia-azaspiro[4.4/5]alkan-3-ones were synthesized via interactions between 4-(2-cyclodenehydrazinyl)quinolin-2(1H)-one and thioglycolic acid catalyzed by thioglycolic acid. We prepared a new family of spiro-thiazolidinone derivatives in a one-step reaction with excellent yields (67-79%). The various NMR, mass spectra, and elemental analyses verified the structures of all the newly obtained compounds. The antiproliferative effects of 6a-e, 7a, and 7b against four cancer cells were investigated. The most effective antiproliferative compounds were 6b, 6e, and 7b. Compounds 6b and 7b inhibited EGFR with IC₅₀ values of 84 and 78 nM, respectively. Additionally, 6b and 7b were the most effective inhibitors of BRAF^V600E (IC₅₀ = 108 and 96 nM, respectively) and cancer cell proliferation (GI₅₀ = 35 and 32 nM against four cancer cell lines, respectively). Finally, the apoptosis assay results revealed that compounds 6b and 7b had dual EGFR/BRAF^V600E inhibitory properties and showed promising antiproliferative and apoptotic activity.

Novel spiro[indene-1,2'-quinazolin]-4'(3'H)-one derivatives as potent anticonvulsant agents: One-pot synthesis, in vivo biological evaluation, and molecular docking studies

A new series of spiro[indene-1,2'-quinazolin]-4'(3'H)-one derivatives 4a-m were synthesized via a one-pot method and evaluated for anticonvulsant activities using pentylenetetrazole (PTZ) and maximal electroshock (MES)-induced seizures. Obtained results demonstrated that these compounds have not anticonvulsant activity in PTZ test while are active in the MES test. Among the synthesized compounds, the best anticonvulsant activity was obtained with compound 4h. This compound also was not neurotoxic. Given that the title new compounds have the pharmacophore requirement for benzodiazepine (BZD) receptor agonist, the most potent compound was assayed in vivo and in silico as BZD receptor agonist. After treatment with flumazenil as a standard BZD receptor antagonist, anticonvulsant activity of compound 4h decreased. Therefore, the involvement of BZD receptors in anticonvulsant activity of this compound confirmed. Furthermore, docking study of compound 4h in the BZD-binding site of GABA_A receptor confirmed that this compound interacted with the important residues.

Modulation of Properties by Ion Changing Based on Luminescent Ionic Salts Consisting of Spirobi(boron ketoiminate)

We report development of luminescent ionic salts consisting of the boron ketoiminate structure, which is one of the robust skeletons for expressing aggregation-induced emission (AIE) properties. From the formation of the boron-centered spiro structure with the ketoiminate ligands, we obtained stable ionic salts with variable anions. Since the ionic salts show T_ms below 100 °C, it was shown that these salts can be classified as an ionic liquid. By using PF₆ anion, the single crystal—which is applicable for X-ray crystallography—was obtained. According to the optical measurements, it was proposed that electronic interaction should occur through the boron center. Moreover, intense emission was observed both in solution and solid. Finally, we demonstrated that the emission color of the PF₆ salt was altered from crystal to amorphous by adding mechanical forces. Based on boron complexation and intrinsic solid-state luminescent characters, we achieved obtainment of emissive ionic materials with environmental responsivity.

Incorporation of Fluorene and Its Heterocyclic Spiro Derivatives To Realize High-Performance and Stable Sky-Blue-Emitting Arylgold(III) Complexes

A series of arylgold(III) complexes of tridentate diphenylpyridine ligand incorporated with fluorene and its heterocyclic spiro derivatives, spiro[fluorene-9,9'-xanthene] and spiro[acridine-9,9'-fluorene], as auxiliary ligands has been prepared. This class of complexes exhibits high decomposition temperatures of up to 387 °C, excellent film morphologies in solid-state thin films with a root-mean-square roughness smaller than 0.20 nm, as well as high photoluminescence quantum yields of up to 0.72 in solid-state thin films. Solution-processed organic light-emitting devices (OLEDs) fabricated from this series of complexes as dopants show intense electroluminescence in the sky-blue region with maximum external quantum efficiencies of 10.0%. Taking advantage of their high thermal stability, vacuum-deposited OLEDs have also been fabricated and satisfactory operational lifetimes of ∼300 h have been recorded.

Spiro-Based Thermally Activated Delayed Fluorescence Emitters with Reduced Nonradiative Decay for High-Quantum-Efficiency, Low-Roll-Off, Organic Light-Emitting Diodes

Herein, we report the use of spiro-configured fluorene-xanthene scaffolds as a novel, promising, and effective strategy in thermally activated delayed fluorescence (TADF) emitter design to attain high photoluminescence quantum yields (Φ_PL), short delayed luminescence lifetime, high external quantum efficiency (EQE), and minimum efficiency roll-off characteristics in organic light-emitting diodes (OLEDs). The optoelectronic and electroluminescence properties of SFX (spiro-(fluorene-9,9'-xanthene))-based emitters (SFX-PO-DPA, SFX-PO-DPA-Me, and SFX-PO-DPA-OMe) were investigated both theoretically and experimentally. All three emitters exhibited sky blue to green emission enabled by a Herzberg-Teller mechanism in the excited state. They possess short excited-state delayed lifetimes (<10 μs), high photoluminescence quantum yields (Φ_PL ∼ 70%), and small singlet-triplet splitting energies (ΔE_ST < 0.10 eV) in the doped films in an mCP host matrix. The OLEDs showed some of the highest EQEs using spiro-containing emitters where maximum external quantum efficiencies (EQE_max) of 11 and 16% were obtained for devices using SFX-PO-DPA and SFX-PO-DPA-OMe, respectively. Further, a record EQE_max of 23% for a spiro-based emitter coupled with a low efficiency roll-off (19% at 100 cd m^-2) was attained with SFX-PO-DPA-Me.

& Moritzi growing in Vietnam

Chemical investigation of chloroform extract of Flacourtia rukam Zoll. & Moritzi stems led to the isolation of one new compound namely rukamtenol together with four known compounds, viz., chaulmooric acid, flacourtin, 3,4,5-trimethoxyphenyl β-D-glucopyranoside, and daucosterol. Their structures and relative stereochemistry have been determined by 1D and 2D NMR analysis, high resolution mass spectroscopy, and compared with those in literatures. Rukamtenol represented the first 2-oxaspiro[4.4]non-8-en-3-one in nature. The relative configuration of rukamtinol was defined using DFT-NMR chemical shift calculations and subsequent DP4 probability method. Rukamtenol, flacourtin, and 3,4,5-trimethoxyphenyl β-D-glucopyranoside were tested for cytotoxic activity toward three MDA-MB-231, HepG2, and RD cancer cell lines. However, they failed to reveal any activity (IC₅₀ > 100 μM) on these cell lines.

Crystal structure of (1'S,2'S,3S)-1'-benzoyl-2'-(4-meth-oxy-phen-yl)-1-methyl-2',5',6',10b'-tetra-hydro-1'H-spiro-[indoline-3,3'-pyrrolo-[2,1-a]isoquinolin]-2-one

The synthesis and crystal structure of the spiro title compound is presented.

In the title spiro compound, C₃₄H₃₀N₂O₃, the central pyrrolidine ring is fused with the tetra­hydro­iso­quinoline ring, both having distorted envelope conformations, with the flap atoms being C and N, respectively. The meth­oxy­phenyl group is attached to the pyrrolidine ring, and is disordered over two positions, with refined occupancies of 0.638 (6):0.362 (6) Å. The central pyrrolidine ring is inclined relative to the tetra­hydro­iso­quinoline group, such that the dihedral between the non-flap atoms of each ring system is 11.29 (7)°. The spiro-linkage creates a dihedral angle of 83.26 (5)° between the indolinone ring and the non-flap atoms of the pyrrolidine ring. In the crystal, mol­ecules are linked via C—H⋯O hydrogen bonds. For the major disorder component, these form C(11) chains that propagate parallel to the a axis.

Spiro Indane-Based Phosphine-Oxazolines as Highly Efficient P,N Ligands for Enantioselective Pd-Catalyzed Allylic Alkylation of Indoles and Allylic Etherification

A series of indane-based phosphine-oxazoline ligands with a spirocarbon stereogenic center were examined for palladium-catalyzed asymmetric allylic alkylation of indoles. Under optimized conditions, high yields (up to 98%) and enantioselectivities (up to 98% ee) were obtained with a broad scope of indole derivatives. The ligand was determined to be the most efficient P,N-ligand for this reaction. Moreover, the ligand was also efficient for Pd-catalyzed asymmetric allylic etherification with hard aliphatic alcohols as nucleophiles.

Crystal structures of 6a,6b,7,11a-tetra-hydro-6H,9H-spiro-[chromeno[3',4':3,4]pyrrolo-[1,2-c]thia-zole-11,3'-indoline]-2',6-dione and 5'-methyl-6a,6b,7,11a-tetra-hydro-6H,9H-spiro-[chromeno[3',4':3,4]pyrrolo-[1,2-c]thia-zole-11,3'-indoline]-2',6-dione

The title compounds, (I) and (II), differ by the presence of a methyl group in position 5 on the 1H-indole-2-one ring of compound (II). There is also a significant difference in the conformation of the five-membered thia­zolidine ring in the two compounds.

The title compounds, C₂₀H₁₆N₂O₃S, (I), and C₂₁H₁₈N₂O₃S, (II), differ by the presence of a methyl group in position 5 on the 1H-indole-2-one ring of compound (II). The two compounds have a structural overlap r.m.s. deviation of 0.48 Å. There is a significant difference in the conformation of the thia­zolidine ring: it has a twisted conformation on the fused N—C bond in (I), but an envelope conformation in compound (II) with the S atom as the flap. The planar pyrrolidine ring of the indole ring system is normal to the mean plane of the five-membered pyrrolidine ring of the pyrrolo­thia­zole unit in both compounds, with dihedral angles of 88.71 (9) and 84.59 (8)°. The pyran rings in both structures have envelope conformations with the methyl­ene C atom adjacent to the C=O group as the flap. In both compounds, there is a short intra­molecular C—H⋯O contact present. In the crystal of (I), mol­ecules are linked by C—H⋯O hydrogen bonds forming chains propagating along the b-axis direction. The chains are linked by N—H⋯π inter­actions, forming layers parallel to (10). In the crystal of (II), mol­ecules are linked by pairs of N—H⋯O hydrogen bonds, forming inversion dimers which are linked by C—H⋯O hydrogen bonds to form a three-dimensional structure.

Bifunctional Heterocyclic Spiro Derivatives for Organic Optoelectronic Devices

A series of heterocyclic spiro derivatives has been successfully synthesized and characterized by photophysical and electrochemical studies. Taking advantage of their excellent hole-transporting properties, highly efficient small-molecular organic photovoltaic devices based on these heterocyclic compounds as donors with very low dopant concentrations have been prepared; particularly, a high open-circuit voltage of up to 1.10 V and a power conversion efficiency of up to 5.12% have been realized. In addition, most of these heterocyclic spiro derivatives are found to be highly emissive in solutions with photoluminescence quantum yields of up to 0.91, and high-performance deep-blue-emitting organic light-emitting diodes (OLEDs) have been achieved. Such devices exhibit a stable deep blue emission with CIE coordinates of (0.16, 0.04) and high external quantum efficiencies of up to 4.7%, which is one of the best values among the reported OLEDs with CIEy < 0.08.

1,3-Dipolar Cycloaddition Reactions of Azomethine Ylides with Carbonyl Dipolarophiles Yielding Oxazolidine Derivatives

We provide a comprehensive account of the 1,3-dipolar cycloaddition reactions of azomethine ylides with carbonyl dipolarophiles. Many different azomethine ylides have been studied, including stabilized and non-stabilized ylides. Of the carbonyl dipolarophiles, aldehydes including formaldehyde are the most studied, although there are now examples of cycloadditions with ketones, ketenes and carboxyl systems, in particular isatoic anhydrides and phthalic anhydrides. Intramolecular cycloadditions with esters can also occur under certain circumstances. The oxazolidine cycloadducts undergo a range of reactions triggered by the ring-opening of the oxazolidine ring system.

Synthesis of D-fructose-derived spirocyclic 2-substituted-2-oxazoline ribosides

The TMSOTf-mediated synthesis of β-configured spirocyclic 2-substituted-2-oxazoline ribosides was achieved using a “Ritter-like” reaction in toluene through nucleophilic addition of electron-rich nitriles to the oxacarbenium ion intermediate of 1,2;3,4-di-O-isopropylidene-β-D-psicofuranose derivatives with concomitant intramolecular trapping of the C2 hydroxymethyl group on the electrophilic nitrilium carbon. These carbohydrate-derived spirooxazolines are stable and were obtained in good yield with high stereoselectivity due to the conformational rigidity imparted by the 3,4-isopropylidene group.

Crystal structure of 3'-(1H-indole-3-carbon-yl)-1'-methyl-2-oxo-4'-(4-oxo-4H-chromen-3-yl)spiro-[indoline-3,2'-pyrrolidine]-3'-carbo-nitrile

In the title compound, C₃₁H₂₂N₄O₄, the pyrrolidine ring adopts a twist conformation on the N—CH₂ bond. The indolin-2-one and the 1H-indole rings are nearly planar (r.m.s. deviations = 0.06 and 0.011 Å, respectively) and are inclined to one another by 34.19 (9)°. The chromene ring system is also nearly planar (r.m.s. deviation = 0.029 Å). It is almost normal to the 1H-indole ring system, with a dihedral angle of 88.71 (8)°, and is inclined to the indolin-2-one ring system by 72.76 (8)°. In the crystal, mol­ecules are linked via N—H⋯O hydrogen bonds, forming slabs parallel to (10-1). The slabs are linked by C—H⋯O hydrogen bonds, forming a three-dimensional structure.

Crystal structure of 5-amino-5'-chloro-6-(4-chloro-benzo-yl)-8-nitro-2,3-di-hydro-1H-spiro-[imidazo[1,2-a]pyridine-7,3'-indolin]-2'-one including an unknown solvent mol-ecule

The asymmetric unit of the title compound, C21H15Cl2N5O4, contains two independent mol-ecules (A and B) having similar conformations. The amine (NH2) group forms an intra-molecular hydrogen bond with the benzoyl group, giving an S(6) ring motif in both mol-ecules. The central six-membered rings adopt sofa conformations and the imidazole rings are planar (r.m.s deviations = 0.0150 and 0.0166 Å). The pyridine and imidazole rings are inclined to one another by 3.54 (1) and 3.03 (1)° in mol-ecules A and B, respectively. In the crystal, mol-ecules are linked by N-H⋯O hydrogen bonds, forming chains along the a axis which enclose R 2 (2)(16) ring motifs. The rings are linked by weak N-H⋯O and C-H⋯O hydrogen bonds and C-H⋯π inter-actions forming sheets lying parallel to (001). A region of disordered electron density, most probably disordered solvent mol-ecules, occupying voids of ca 753 Å(3) for an electron count of 260, was treated using the SQUEEZE routine in PLATON [Spek (2009 ▶). Acta Cryst. D65, 148-155]. Their formula mass and unit-cell characteristics were not taken into account during refinement.