10.1021/jo01310a057
The research explores the synthesis and reactions of various organic compounds. It includes the preparation of indole derivatives using compounds like 1-methyl-2-vinylpyrrole, methyl propiolate, and hydroquinone, resulting in products such as dimethyl indole-6,7-dicarboxylate and methyl 1-tert-butylindole-7-carboxylate, characterized by melting points, IR spectra, NMR spectra, and elemental analysis. Additionally, the study introduces alkyl and aryl α-methoxyvinyl carbonates (3a-c) as efficient reagents for carboalkoxylation and carboaryloxylation of amines, including weakly basic ones, under mild conditions, yielding high-quality N-carboalkoxylated and N-carboaryloxylated compounds. The research also examines the reactions of [3-(dimethylamino)-2-azaprop-2-en-1-ylidene]dimethylammonium chloride with hydrazines and amidines, producing 1,2,4-triazoles and substituted products, with detailed spectral data confirming the structures of the synthesized compounds.
10.1142/S1088424613500909
This study focuses on the synthesis and characterization of three novel hydroquinone-based subphthalocyanine (SubPc) dimers. The researchers used phthalonitriles and BCl? to synthesize chloro-subphthalocyanines (Cl-SubPcs), which then underwent axial substitution with hydroquinone to form hydroquinone-substituted SubPcs (Hq-SubPcs). These Hq-SubPcs acted as nucleophiles and reacted with Cl-SubPcs to create symmetrical and unsymmetrical dimers. The synthesis involved reacting hydroquinone and the respective SubPcs in a 1:1 molar ratio in toluene at 180 °C in a pressure vessel. The resulting dimers were characterized using 1H NMR, 13C NMR, UV-vis, fluorescence, and mass spectral analysis. The study highlights the potential of these dimers for applications in optoelectronic devices due to their enhanced solubility and tailored absorption properties.
10.1016/s0022-328x(97)00456-7
The study investigates the formation of dimeric and trimeric molybdenum(II) complexes containing 2-substituted 3-bonded butadienyl bridging ligands. The starting material used is [MoCI(CO)2(@-CH2(COCI)C=CH2)phen] (phen = 1,10-phenanthroline) (1). When 1 reacts with 1,2-ethanediol or N,N'-diethylethylenediamine in a 2:1 mole ratio, dimeric complexes [MoCI(CO)2(@-CH/(COACH2)C=CH2)phen]2 are formed, where A represents the substituent group (A = O for ester, A = NEt for amide). Reactions with hydroquinone or 1,4-phenylenediamine yield monomeric complexes [MoCI(CO)2(@-CH2(COA)C=CH2)phen], while dimeric complexes are isolated from reactions involving 4,4'-ethylenedianiline or p-xylylenediamine. Attempts to prepare a novel complex bridged by three linked amide substituted butadienyl groups using diethylenetriamine were unsuccessful. However, reaction of 1 with triethanolamine or tris(2-aminoethyl)amine in a 3:1 mole ratio gives trimeric complexes [MoCI(CO)2(~/a-CH2(COACH2CH2)C=CH2)phen]3 N (A = O, NH) in good yield. The study establishes conditions for the formation of these complexes and examines the boundaries of dimer and trimer formation using various bifunctional and trifunctional reagents.
10.1021/ol102398y
The study presents an innovative iterative synthesis method for heterotelechelic oligo(phenylene-vinylene)s (OPVs) utilizing olefin cross-metathesis. This approach allows for the creation of oligomers with controlled lengths and paves the way for their assembly into repeating sequence copolymers (RSCs). The process is initiated by a cross-metathesis reaction between olefin-terminated oligomers and a vinylbenzaldehyde, yielding aldehyde-end-capped OPVs. These can then be transformed into metathesis-ready vinyl groups or used for further functionalization, such as the formation of donor-acceptor complexes. The study demonstrates the synthesis of various OPVs with different conjugation lengths, which exhibit tunable optical properties, and also explores the potential for creating complex copolymers through the conversion of OPVs into RSCs. The method's versatility is highlighted by the successful functionalization of OPVs and the potential for applying this metathesis-based coupling to phenylene monomers with a variety of substituents.
10.1021/ol901004e
The study presents a biomimetic synthesis of the dimeric metabolite acremine G, which was achieved through a highly regioselective and stereoselective Diels-Alder reaction between a TBS-protected hydroquinone diene and a structurally related alkenyl quinone. The synthesis involved the use of various chemicals, including toluhydroquinone as the starting material, iodine and silver trifluoroacetate for selective iodination, palladium(II) acetate and triphenylphosphine for the Heck coupling reaction, acetyl chloride and pyridine for dehydration to form the diene, and potassium fluoride, hydrobromic acid, and acetic acid for deprotection steps. These chemicals served the purpose of constructing the necessary precursors and facilitating the key Diels-Alder reaction, which led to the formation of acremine G after a series of transformations and deprotection steps. The study also proposed a mechanism for the oxidation of intermediates to acremine G, suggesting a radical pathway involving electron transfer to molecular oxygen.
10.1021/acs.orglett.0c03990
The study presents an asymmetric total synthesis of (+)-PD-116740, an angucyclinone with potent anticancer activity. The synthesis involved a convergent approach with naphthalene-1,5-diol as the starting material, which was converted into quinone derivatives and then reduced to hydroquinone. Selective protection and bromination steps led to the formation of coupling precursors. The D ring fragment was prepared from benzyl alcohol, with TBS protection, lithium/bromide exchange, and conversion to an alkyne. A Pd-catalyzed Suzuki-Miyama coupling reaction combined the A/B and D ring fragments. Asymmetric dihydroxylation using osmium tetroxide and a chiral ligand introduced chirality. The core trans-9,10-dihydrophenanthrene-9,10-diol unit was constructed via oxidative cyclization using Cu(OH)OTf·NMI2 as the oxidant, which also facilitated phenol oxidation. Finally, global deprotection yielded PD-116740.
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