An efficient and readily scalable thioetherification between 1,1-diphenylethene (DPE) and sodium arylsulfinate was developed for the synthesis of 1,1-diphenylvinylsulfide (DPVS) with the yield up to 99 %. The photophysical properties of DPVS show that the introduction of arylsulfenyl groups onto the parent molecule DPE makes DPVS a novel type of aggregation-induced emission (AIE) luminogen (AIEgen) with large Stoke's shift (up to 188 nm). These DPVS possess AIE properties due to restriction of intramolecular motions (RIM), as demonstrated by crystal structure analysis.
View Article and Find Full Text PDFBy using a transfer hydrogenative coupling strategy, we herein describe a new method for the efficient synthesis of anthranilic acid derivatives, a significantly important class of compounds with extensive applications in organic synthesis and the discovery of bioactive molecules, from 2-nitroaryl methanols and readily available alcohols/amines. The synthesis proceeds with the merits of no need for a transition metal catalyst, operational simplicity, broad substrate scope, good functional tolerance, and high step efficiency, which offers a useful alternative to access anthranilic acid derivatives.
View Article and Find Full Text PDFA general catalytic hydrogen transfer-mediated α-functionalization of 1,8-naphthyridines is reported for the first time that benefits from a hydrogen transfer-mediated activation mode for non-activated pyridyl cores. The pyridyl α-site selectively couples with the C8-site of various tetrahydroquinolines (THQs) to afford novel α-functionalized tetrahydro 1,8-naphthyridines, a class of synthetically useful building blocks and potential candidates for the discovery of therapeutic and bio-active products. The utilization of THQs as inactive hydrogen donors (HDs) appears to be a key strategy to overcome the over-hydrogenation barrier and address the chemoselectivity issue.
View Article and Find Full Text PDFBy an external hydrogen transfer-mediated activation mode, we herein demonstrate a new palladium-catalyzed direct α,β-coupling of different types of N-heteroarenes. Such a selective coupling reaction proceeds with the advantages of operational simplicity, high atom-economical efficiency, and use of safe and abundant i-propanol as the activating agent, offering a practical way to access nitrogen bi-heteroarenes. Preliminary exploration has revealed that the obtained bis-1,10-phenanthroline 2qq' as a ligand is capable of improving a copper catalyst for C-C bond formation.
View Article and Find Full Text PDFA ruthenium-catalysed annulative transfer hydrogenation strategy, enabling straightforward access to tetrahydro fused-pyrazine derivatives from N-heteroaryl diamines and vicinal diols, has been demonstrated for the first time. Such a synthesis proceeds with unprecedented synthetic effectiveness including high step- and atom efficiency, generation of water as the sole by-product, short reaction time and no need for external high pressure H2 gas, offering an important basis for the transformation of vicinal diols, a class of bio-mass derived resources, into functionalized products.
View Article and Find Full Text PDFA novel asymmetric phenol-based 'end-off' dinucleating ligand 2-{[(2-piperidylmethyl)amino]methyl}-4-bromo-6-[(1-methylhomopiperazine-4-yl)methyl]phenol (HL) and three dinuclear nickel(II) complexes, [Ni₂L(μ-OH)] (ClO₄)₂ (1), [Ni₂L(DNBA)₂(CH₃CN)₂]BPh₄ (2) and [Ni₂L(BPP)₂(CH₃CN)₂]BPh₄ (3) have been synthesized and characterized by a variety of techniques including: NMR, infrared and UV-vis spectroscopies, mass spectrometry, elemental analysis, molar conductivity, thermal analysis, magnetochemistry and single-crystal X-ray diffractometry. The UV-vis spectrum of complex 1 exhibits a strong peak at 510 nm, a characteristic absorption of a d-d transition of the square-planar four-coordinated Ni(II) center. Utilizing this feature, the stepwise formation of mono- and dinickel centers in solution can be monitored.
View Article and Find Full Text PDFA simple and efficient method for the synthesis of gamma,delta-alkynyl-beta-amino acid derivatives by a copper-catalyzed three-component amine-alkyne-alkyne addition reaction was developed. Various gamma,delta-alkynyl-beta-amino acid derivatives were synthesized in moderate to good yields in one step. With chiral prolinol derivatives employed as the amine component, excellent diastereoselectivities (up to >99:1 diastereomeric ratio (dr)) were obtained.
View Article and Find Full Text PDFA highly efficient alkynylation-cyclization of terminal alkynes with salicylaldehydes leading to substituted 2,3-dihydrobenzofuran-3-ol derivatives was developed by using Cy(3)P-silver complex as catalyst in water. Counter anions in the silver complex proved to be the key factor to Z/E stereoselectivity control. Aurones can also be obtained effectively from the cascade reaction followed by oxidation without further purification.
View Article and Find Full Text PDFStep in time: 2,5-Disubstituted furans can be prepared from terminal alkynes in one pot using two successive catalytic reactions (see scheme; p-TSA = para-toluenesulfonic acid). First, a 1,3-dienyl alkyl ether is produced by the dimerization of a terminal alkyne and addition of an alcohol catalyzed by [RuCp*(NCMe)(3)][PF(6)]. Then, consecutive hydrolysis and cyclization catalyzed by CuCl(2) provides the 2,5-disubstituted furan.
View Article and Find Full Text PDFThe efficient palladium-catalyzed conjugate addition of terminal alkynes to alpha,beta-unsaturated carbonyl compounds has been developed using electron-rich ligands, producing the corresponding gamma,delta-alkynyl ketone and gamma,delta-alkynyl esters in good yields.
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