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61.
Craig M. Anderson Garrett Brown Matthew W. Greenberg David Yu Nellie Bowen Rahma Ahmed Melissa Yost-Bido Alina Wray 《Tetrahedron letters》2019,60(43):151156
Several thiophene-based N^C ligands were synthesized. Strategically, a bromide was incorporated on the 2-position of the thiophene ring. When allowed to react with the platinum tetramethyl dimer, [Pt2Me4(µ-SMe2)2], platinum(IV) platinacycles were formed by oxidative addition of the C(sp2)-X bond. These platinum(IV) compounds were characterized by NMR and HRMS. The platinum (IV) compounds were subsequently subjected to thermolysis. A series of reactions occurred, including selective C-C reduction elimination and selective C-H oxidative addition, giving mixtures of platinum(II) products with varying degrees of regioselectivity. 相似文献
62.
Yanguang Bao 《高分子科学杂志,A辑:纯化学与应用化学》2019,56(6):605-608
In this paper, we present a compound, 2,3-diphenyl butyronitrile (DPBN), which can be used as a new and efficient radical initiator for the polymerization of methyl methacrylate (MMA) and styrene (St). Very different from other compounds as a carbon-carbon initiator, DPBN is an unsymmetrically substituted ethane and works with high initiation reactivity at lower temperatures. This new compound as an initiator exhibits various advantages, such as easy preparation, high initiation reactivity, safe use and storage, and convenient handling. 相似文献
63.
Sedigheh Alavinia Ramin Ghorbani-Vaghei Jamshid Rakhtshah Jaber Yousefi Seyf Iman Ali Arabian 《应用有机金属化学》2020,34(3):e5449
A porous cross-linked poly (ethyleneamine)-polysulfonamide (PEA-PSA) as a novel organic support system is synthesized in the presence of silica template by nanocasting technique. The paper demonstrates immobilization of CuI nanoparticles inside the pores (PEA-PSA@CuI) for the facile recovery and recycling of these nanoparticles. The presence of porous PEA-PSA and PEA-PSA@CuI nanocomposites was confirmed using FT-IR spectroscopy, FE-SEM, EDX, TGA, XRD, TEM, BET, XPS, WDX, 1H NMR, and ICP-OES techniques. The PEA-PSA@CuI along with Ag(I)/K2S2O8 was implemented as a reusable cooperative catalyst-oxidant system in the N-arylation of p-toluenesulfonamide with substituted carboxylic acids in mild condition. So, the novel decarboxylative cross-coupling catalyzed by copper and silver has been developed. Aromatic, secondary and tertiary aliphatic acids underwent high efficient decarboxylative processes with p-toluenesulfonamide to afford the corresponding products. This method provides a practical approach for the flexible synthesis of sulfonamides from the readily affordable substrates. The catalyst is highly reusable and efficient, especially in terms of time and yield of the desired product. 相似文献
64.
Sateesh Kumar Arepalli Yunseon Choi Kiho Lee Jong-Soon Kang Jae-Kyung Jung Heesoon Lee 《Tetrahedron》2018,74(14):1646-1654
An efficient, transition-metal-free cascade synthetic method has been developed for new 2-aryl/heteroaryl sulfonated benzo[f][1,7]naphthyridines. It is tert-butyl hydroperoxide (TBHP) mediated highly regioselective sulfonylation?cyclization?aromatization process between N-(3-aryl/heteroarylprop-2-yn-1-yl)quinolin-3-amines and aryl/heteroaryl sulfonylhydrazides. This synthetic protocol offers one-step strategy for CS and CC bond formations with a broad range of functional group tolerance. It is a simple, mild, and atom-economical route for the synthesis of various valuable functionalized 1, 2-aryl/heteroaryl sulfonated benzo[f][1,7]naphthyridines in moderate yields. Since the core motif of 2-sulfonated benzo[f][1,7]naphthyridines are biologically and pharmaceutically important (TLR activity 7, 8 modulators). Additionally, the synthesized derivatives were evaluated for their in vitro cytotoxic activities against six human cancer cell lines including lung (NCIH23), colon (HCT15), gastric (NUCG-3), renal (ACHN), prostate (PC-3), and breast (MDA-MB-231) cell lines. These compounds displayed significant cytotoxic activities against all tested human cancer cell lines. 相似文献
65.
Christophe Desmarets Alain Walcarius Benoît Champagne Raphaël Schneider 《Tetrahedron》2008,64(2):372-381
Stable Pd(0) nanoparticles were prepared at room temperature in 1,4-dioxane from PdCl2 using N,N′-bis(4-methoxyphenyl)-(1,1′-binaphthyl)-4,4′-diamine (naphthidine) as reducing and stabilizing agent. This procedure resulted in Pd(0) particles possessing an average diameter of ca. 25 nm stabilized against aggregation due to a barrier of the naphthidine di(radical cation) Napht2.2+. These particles were evaluated for their capability to act as catalysts in Suzuki-Miyaura coupling reactions. The Pd(0)/Napht2.2+ provides a general and convenient method to prepare biaryls from aryl bromides or iodides and boronic acids with a broad range of functional groups in 1,4-dioxane at 80 °C and under aerobic conditions. 相似文献
66.
J.S. Yadav B.V. Subba Reddy Swapan Kumar Biswas Sandip Sengupta P. Vishnumurthy 《Tetrahedron letters》2008,49(6):1034-1036
Phenacyl bromides undergo smooth vic-diallylation and dipropargylation with allyl and propargyl indium reagents generated in situ from metallic indium and allyl or propargyl bromide to produce 4-arylocta-1,7-dien-4-ol derivatives in good yields. Phenacyl chloride and azide also participated effectively in bis-allylation. Similar results are also obtained from in situ generated allyl or propargyl zinc bromide. 相似文献
67.
A new total synthesis of the alkaloid variolin B is achieved by a selective and sequential palladium-mediated functionalization of a trihalo-substituted pyrido[3′,2′:4,5]pyrrolo[1,2-c]pyrimidine. This intermediate is obtained by a new heterocyclization reaction between an appropriate bromomethyl azaindole and N-tosylmethyl dichloroformimide. The methodology may be effective for the synthesis of some analogs by substitution on the relatively unexplored C4 and C9 positions of the alkaloid. 相似文献
68.
The synthesis of diphenylarylphosphane and 1,2-bis(diarylphosphanyl)ethane ligands, where the aryl group is -C6H4CH2CH2SiMe2CH2OC6H4-3-NMe2, their palladium(II) complexes, and their corresponding ammonium-quaternized derivatives is described. These new phosphanes were devised as models of potentially water-soluble dendritic carbosilane ligands, although the solubility brought about by the quaternized N-trimethylanilinium groups is scarce. The palladium(II) complexes have been fully characterized by 1H, 13C, and 31P NMR spectroscopy and mass spectrometry, and have been tested in the Hiyama cross-coupling reaction between tri(methoxy)phenylsilane and 3-bromopyridine in aqueous sodium hydroxide solution. 相似文献
69.
工业发展与人类活动导致大气中CO2浓度逐年升高, 引发一系列生态环境问题. 将CO2光催化转化为高附加值化学物质不仅有利于缓解环境压力,也可以带来额外经济价值. 然而, 由于多电子利用效率低和C―C偶联动力学缓慢, 光还原CO2制多碳产品面临产率低和选择性差等挑战. 光催化剂活性位点调控能够有效解决上述问题. 我们综述了近几年用于光还原CO2催化剂表面活性位点设计的研究进展, 主要包括缺陷位点、 金属位点以及掺杂位点等, 从活性位点的角度为光还原CO2催化剂设计提供新视角, 并对开发高效光催化剂具有启发意义. 相似文献
70.
One novel carbon-carbon bond insertion reaction of arynes has been developed. By this reaction β-keto sulfones can insert the triple bond of arynes to prepare polysubstituted ortho-keto benzyl sulfones. 相似文献