Cobalt(II)-Catalyzed C(sp3)−C(sp3) Coupling for the Direct Stereoselective Synthesis of 2-Deoxy-C-Glycosides from Glycals

We report a ligand-controlled Co^II-catalyzed C(sp³)−C(sp³) coupling hydroalkylation for direct and β-selective synthesis of 2-deoxy-C-glycosides from glycals. This reaction proceeds by a radical pathway for alkyl halide activation and is β-selective through ligand control. This approach may inspire the development of further stereoselective coupling reactions with potential application in the field of carbohydrates.     

Two new isoflavone 7-O-α-4″-anhydro-4″,5″-didehydroglucuronides from Streptomyces sp. LZ35ΔgdmAI

Two isoflavone 7-O-α-4″-anhydro-4″,5″-didehydroglucuronides, namely daidzein 7-O-α-4″-anhydro-4″,5″-didehydroglucuronide (1) and genistein 7-O-α-4″-anhydro-4″,5″-didehydroglucuronide (2), were isolated and identified from the mutant strain of Streptomyces sp. LZ35ΔgdmAI. Their structures were elucidated by the analysis of their high resolution mass spectrometry (HR–MS) and 1D, 2D Nuclear magnetic Resonance (NMR) spectroscopic data. They are new natural products and maybe the transformed products of the soybean meal by Streptomyces sp. LZ35ΔgdmAI.     

Rhodium(II)-Catalyzed Selective C(sp3)−H Amination of Alkanes

The development of an efficient catalytic system enabling the conversion of alkanes to valuable nitrogen-containing building blocks is reported. Light alkanes can be selectively functionalized by an intermolecular C(sp³)−H amination reaction that proceeds at room temperature in the presence of only 1 mol % of a dirhodium(II) complex. Selective amination of tertiary C(sp³)−H within acyclic or cyclic alkanes used as limiting components leads to the corresponding amides isolated with yields in the 51–96 % range. The reaction, that can be performed on a gram-scale, applies with equal levels of efficiency and selectivity to more complex hydrocarbons.     

红树林耐酸真菌Aspergillus sp.OUCMDZ-1914次生代谢产物研究

为获得活性微生物代谢产物,从海南文昌红树林根泥样品中分离筛选到耐酸真菌Aspergillus sp.OUCMDZ-1914,通过酸性条件发酵培养,发酵产物经过硅胶柱色谱、凝胶柱色谱和半制备高效液相色谱进行分离纯化,运用NMR、MS、UV、IR、X射线单晶衍射等手段鉴定了9个化合物的化学结构,即:(2Z,3E,5E,7E,9E)-4,10-二甲基-11-[3-(2,5-二氧亚基四氢吡咯)基]-2-(2-羟基乙亚基)-11-氧亚基-3,5,7,9-十一碳四烯酸甲酯(1)、RKB-3384A(2)、JBIR-74(3)、JBIR-75(4)、secalonic acid D(5)、oxaline(6)、meleagrin(7)、okaramine H(8)、citreorosein(9),其中1为新化合物.活性测试表明化合物2对甲型流感病毒H1N1的抑制活性与阳性药利巴韦林相当,IC50为116.2μmol/L;化合物5对A549、MCF-7和K562细胞株表现出较好的抑制活性,IC50分别0.23,4.45和3.68μmol/L;化合物6具有α-糖苷酶抑制活性,IC50为0.84mmol/L,与阳性药阿卡波糖相当.     

A New Virginae Butanolide from Streptomyces sp.

A novel butanolide, named virginaebutanolide F (1), was isolated from the lyophilized culture broth of Slreptomyces sp., along with a known compound virginaebutanolide C (2). Their structures including the stereochemistry were elucidated on the basis of extensive 1D and 2D NMR as well as HRESI-MS and CD spectroscopic analysis.     

可见光催化C(sp3)-C(sp3)键的构筑

本文对近年来可见光催化构筑C(sp ³)-C(sp ³)键的国内外最新研究成果进行概述,着重阐述了各类催化的催化体系、反应机理及在合成生物活性分子或药物分子方面的应用。在可见光催化的反应体系中引入过渡金属或手性催化剂,构建新颖的协同催化体系,可以实现在温和的条件下对C—C键构筑的精确控制,对于手性药物的设计、开发具有重要的意义。最后,对未来可见光催化构筑C—C键的发展进行展望。     

4′, 4″-Dihydroxy-3′,5′,3″,5″-tetrabrom-1,4-diphenyl-naphthalin-2, 3-dicarbonsäure-anhydrid

Ohne Zusammenfassung     

A Novel Sesquiterpene Isolated from Stereum sp. 8954

The basidiomycete Stereum sp. 8954 was collected in Xishuangbanna, Yunnan Province, and the mycelium of Stereum sp. 8954 was separated from fruit body and deposited in Laboratory for Conservation and Utilization of Bio-resources, Yunnan University. After fermentation, a novel sesquiterpene was isolated from the culture of the strain. The present paper deals with the structural elucidation of the new compound. Experimental Stereum sp. 8954 was fermented with PDA medium (10 L) at 26 oC fo…     

A New Isomalabaricane Triterpenoid from Sponge Jaspis sp.

From the marine sponge Jaspis sp., a new isomalabaricane triterpenoid 22, 23-dihydrostellettin D (1) was isolated, and its structure was established on the basis of IR, MS and extensive 2D NMR spectroscopic analysis. It is a unique skeleton compound rarely obtained from Chinese marine organisms.     

Copper(II), zinc(II) and mixed metal copper(II)-zinc(II) peroxocomplexes containing 2,2′,6′,2″-terpyridine

Summary Facile reaction of 2,2,6,2-terpyridine (L; terpy) with copper or zinc powders or their mixtures, in the presence of an excess of H₂O₂, leads to novel complexes [Cu(L)-(O₂ ^2–)]·3H₂O, [Zn(L)(O ₂ ^2– )]·H₂O and [Cu,Zn(L)₂(O ₂ ^2– )₂]· 4H₂O, respectively, which were isolated and characterized by elemental and micro- analysis, e.s.r., electronic, i.r. and thermogravimetric analysis in air and argon.     

Trienic α-pyrone and ochratoxin derivatives from a sponge-derived fungus Aspergillus ochraceopetaliformis

A new trienic α-pyrone derivative asteltoxin G (1) bearing a tetrahydrofuran ring and a new ochratoxin derivative named ochratoxin A₁ (5), along with seven known compounds, were isolated from a sponge-derived fungus Aspergillus ochraceopetaliformis. The compounds (1–9) were evaluated on the basis of spectroscopic analyses and comparison with those of the reported data. The new compound ochratoxin A₁ (5) exhibited anti-inflammatory activity against IL-6 and TNF-α expression of the LPS-induced THP-1 cells with inhibitory rates of 74.4 and 67.7% at concentration of 10 μM, respectively.     

镍催化构筑C(sp3)—C(sp3)键反应研究进展

过渡金属催化的偶联反应是构筑C-C键的高效方法,在有机合成中得到了广泛的应用.然而,相对于Heck反应、Negishi偶联与Suzuki偶联等构筑C（sp²）-C（sp²）键的反应,过渡金属催化的构筑C（sp³）-C（sp³）键的偶联反应较难进行,发展较晚.近年来,烷基-烷基C-C键偶联反应受到广泛的重视,一些高效催化剂被开发出来,其中镍催化剂展示出独特的催化活性和选择性.本文将综述镍催化烷基-烷基C-C键偶联反应最新研究进展,主要包括烷基亲电试剂与金属有机试剂交叉偶联反应、导向基参与的C（sp³）-H键活化的偶联反应、镍-光反应催化剂协同催化偶联反应、烷基亲电试剂与亲电试剂的还原偶联反应和镍催化烯烃加成反应等.     

New Synthesis of 3,3′,3″-Nitrilotripropionic Acid

Russian Journal of Organic Chemistry - A new procedure has been developed for the synthesis of 3,3′,3″-nitrilotripropionic acid (NTP) by reaction of formamide with acrylic acid in a...     

Two Phaeophytin Type Analogues from Marine Sponge Dysidea sp.

A new compound named 13b (S)-hydroxy-17c-ethoxypheaophorbide a (2) together with a known compound 17c-ethoxypheaophorbide a (1) were isolated from marine sponge Dysidea spcollected in South China sea. The structures were elucidated by spectroscopic analysis as well as comparison with those reported in literatures.     

Carbon(sp(3) )Fluorine Bond-Forming Reductive Elimination from Palladium(IV) Complexes

Pd(IV) -fluoride complexes, some of which are remarkably insensitive to water, have been synthesized and used in the title reaction, which proceeds with high selectivity to give the product of the C(sp(3) )?F coupling (see scheme, TfO=trifluoromethanesulfonate). Preliminary mechanistic studies implicate a pathway involving dissociation of pyridine followed by direct C?F coupling at the Pd center.     

Platinum(IV) centres with agostic interactions from either sp² or sp³ C-H bonds

Agostic complexes of platinum(IV) have been isolated and characterised. A Pt(II) sp3 agostic complex maintains the agostic interaction upon oxidation giving a Pt(IV) sp3 agostic complex; in another Pt(IV) complex the agostic interaction from an sp2 C-H bond is sufficient to displace another ligand.     

软珊瑚共附生真菌Aspergillus sp.EGF15-0-3的柳珊瑚酸类代谢产物研究（英文）

首次从软珊瑚共附生曲霉属真菌Aspergillussp.EGF15-0-3中分离得到可逆性胆碱酯酶抑制剂环戊烷倍半萜类化合物柳珊瑚酸(1)及其类似物2-脱氧-2β-羟基柳珊瑚酸(2),并确定其结构.根据单菌株多次级代谢产物(OSMAC)策略和富营养化培养,在23种不同的培养基中首次应用全球天然产物分子网络(GNPS)检测1和2是否存在,并选出1和2的最佳培养基组成.结果表明,除马铃薯葡萄糖肉汤(PDB)培养基外,1还存在其他6种培养基中,2的含量在液体和大米培养基中不同,其中GPY+CaCO_3培养基为1和2的最佳培养基.首次证实软珊瑚共附生曲霉属真菌EGF15-0-3是1和2的可能微生物来源,同时也验证了海洋无脊椎动物产生新颖的具有生物活性的次级代谢产物通常来自内生、附生、共生或环境微生物的假说.     

SYNTHESIS OF 4－S－（5″－ALKYL－4″－AMINO－1″，2″，4″－TRIAZOLE－3″－YL）－4－DEOXY－4′－DEMETHYL－EPIPODOPHYLLOTOXIN ANALOGUES

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