Chemo- and site-selective functionalization of phenols offers a rapid strategy for the synthesis of phenol derivatives with diverse structures. Herein, we report a Pd-catalyzed regioselective C-H bond allylic alkylation of phenols with 1,3-dienes, which has precision reactivity at the ortho C-H bond of 2-naphthols, 1-naphthols, and electron-rich phenols. The reaction is accelerated by a diphosphine ligand, does not need any other additive, and features broad substrate scope and good chemo- and regioselectivity. In addition, we have also investigated the asymmetric variant, and the product could be achieved in up to 55% ee.

Ke-Qin Wu

Hui Li

Ao Zhou

Wei-Ran Yang

Qin Yin

The Journal of Organic Chemistry

Palladium-Catalyzed Chemo- and Regioselective C–H Bond Functionalization of Phenols with 1,3-Dienes

钯催化苯酚与1,3-二烯的化学和区域选择性C-H键功能化

1,3,5-Triazinanes, as a kind of versatile building block, are applied in the synthesis of chromeno[2,3-d]pyrimidin-5-one derivatives via two different reaction modes, which perfectly exhibits the powerful function of 1,3,5-triazinane as a three-atom synthon along with the structure variation of another substrate. The two annulation reactions proceed under mild conditions and bear broad substrate scope and high yield.

Taimin Wang

Biwei Zhang

Lin Hu

Haiyan Sun

Yan Wang

Hongbin Zhai

Bin Cheng

Synthesis of Chromeno[2,3-d]pyrimidin-5-one Derivatives from 1,3,5-Triazinanes via Two Different Reaction Pathways

通过两种不同反应途径从1,3,5-三嗪烷合成色烯并[2,3-d]嘧啶-5-酮衍生物

C(aryl)-OMe bond functionalization catalyzed by cobalt(II) chloride in combination with a nacnac-type ligand and magnesium as a reductant is reported. Borylation and benzoylation of aryl methoxides are demonstrated, and C(aryl)-SMe bond borylation can be achieved under similar conditions. This is the first example of achieving these transformations using cobalt catalysis. Mechanistic studies suggest that a Grignard reagent is generated as an intermediate in a rare example of a magnesiation via a C-O bond activation reaction. Indeed, an organomagnesium species could be directly observed by electrospray ionization mass spectroscopic analysis. Kinetic experiments indicate that a heterogeneous cobalt catalyst performs the C-O bond activation.

Ewa Pietrasiak

Seongmin Ha

Seungwon Jeon

Jongheon Jeong

Jiyeon Lee

Jongcheol Seo

Eunsung Lee

Cobalt-Catalyzed Formation of Grignard Reagents via C–O or C–S Bond Activation

钴催化通过C-O或C-S键活化形成格氏试剂

Ionic liquids based on aryl-/alkyl-substituted imidazolium salts constitute a new generation of ionic liquids with a high degree of flexibility. The new concept could now also be extended to aryl-/alkyl-substituted 1,2,4-triazolium salts. The two different phenyl-substituted 1H- and 4H-1,2,4-triazoles have been synthesized by a coupling reaction or a one-pot synthesis with diformylhydrazine, respectively. Reaction with alkyl bromides provided the 1,2,4-triazolium bromides, and an anion-exchange reaction led to the corresponding bis(trifluoromethylsulfonyl)imide salts with melting points well below 100 °C.

Dirk Meyer

Thomas Strassner

1,2,4-Triazole-Based Tunable Aryl/Alkyl Ionic Liquids

基于1,2,4-三唑的可调芳基/烷基离子液体

The direct chlorination and bromination of (E)-enamines and (Z)-enamides to the corresponding (Z)-configurated α-chloroenamines, α-bromoenamines, and α-chloroenamides have been realized using NiCl2·6H2O or tetrabutyl ammonium bromide as a halide source and (1,1-diacetoxyiodo)benzene as an oxidant. The high stereoselective reactions which produce products with only (Z)-configurations can be attributed to the structure of the intermediates, the conformations of which are controlled by the electrostatic attractions between the positively charged nitrogen atoms and the oxygen atoms of the carbonyl group. This type of electrostatic effect has never been reported in olefin halogenations. For this reason, the three-membered bromonium ion is only a minor intermediate in the enamine bromination pathway. These methods open pathways to prepare α-chloroenamines and α-chloroenamides, which are not accessible via the currently used methods.

Linlin Xing

Chunbao Li

Stereoselective Chlorination and Bromination of Enamides and Enamines via an Electrostatic Attraction Effect Using (1,1-Diacetoxyiodo)benzene and a Halide Source

通过(1,1-二乙酰氧基碘)苯和卤化物源的静电吸引效应实现烯酰胺和烯胺的立体选择性氯化和溴化

ADVERTISEMENT RETURN TO ISSUECommunicationNEXTChiral π-Complexes of Heterocycles with Transition Metals: A Versatile New Family of Nucleophilic CatalystsJ. Craig Ruble and Gregory C. FuView Author Information Department of Chemistry, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139 Cite this: J. Org. Chem. 1996, 61, 21, 7230–7231Publication Date (Web):October 18, 1996Publication History Received30 July 1996Published online18 October 1996Published inissue 1 January 1996https://pubs.acs.org/doi/10.1021/jo961433ghttps://doi.org/10.1021/jo961433grapid-communicationACS PublicationsCopyright © 1996 American Chemical SocietyRequest reuse permissionsArticle Views3715Altmetric-Citations200LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InRedditEmail Other access optionsGet e-AlertscloseSupporting Info (1)»Supporting Information Supporting Information SUBJECTS:Alcohols,Catalysts,Heterocyclic compounds,Organic reactions,Post-translational modification Get e-Alerts

J. Craig Ruble

Gregory C. Fu

Chiral π-Complexes of Heterocycles with Transition Metals: A Versatile New Family of Nucleophilic Catalysts

杂环与过渡金属的手性π-配合物：一类多功能的新型亲核催化剂

The facile preparation of three regioisomeric thienopyrrolo[3,2,1-jk]carbazoles applying a convenient C-H activation approach is presented. The incorporation of thiophene into the triarylamine framework significantly impacted the molecular properties in comparison to the analogous indolo[3,2,1-jk]carbazole scaffold. Dependent on the exact substitution pattern, the absorption onsets of the new materials are shifted toward slightly higher wavelengths compared to the analogous indolo[3,2,1-jk]carbazole, whereas the emission maxima of the sulfur derivatives is shifted from 375 to 410 nm. In analogy, the HOMO-LUMO energy gap of the thienopyrrolo[3,2,1-jk]carbazoles is reduced compared to indolo[3,2,1-jk]carbazole. Therefore, the developed thienopyrrolo[3,2,1-jk]carbazoles enrich the family of triarylamine donors and constitute a novel building block for functional organic materials.

Dorian Bader

Johannes Fröhlich

Paul Kautny

Thienopyrrolo[3,2,1-jk]carbazoles: Building Blocks for Functional Organic Materials

硫代吡咯并[3,2,1-jk]咔唑：功能性有机材料的构建模块

The internal charge transfer (ICT) type fluoroionophore arylvinyl-bipy (bipy = 2,2′-bipyridyl) is covalently tethered to the spirolactam form of rhodamine to afford fluorescent heteroditopic ligand 4. Compound 4 can be excited in the visible region, the emission of which undergoes sequential bathochromic shifts over an increasing concentration gradient of Zn(ClO4)2 in acetonitrile. Coordination of Zn2+ stabilizes the ICT excited state of the arylvinyl-bipy component of 4, leading to the first emission color shift from blue to green. At sufficiently high concentrations of Zn(ClO4)2, the nonfluorescent spirolactam component of 4 is transformed to the fluorescent rhodamine, which turns the emission color from green to orange via intramolecular fluorescence resonance energy transfer (FRET) from the Zn2+-bound arylvinyl-bipy fluorophore to rhodamine. While this work offers a new design of ratiometric chemosensors, in which sequential analyte-induced emission band shifts result in the sampling of multiple colors at different concentration ranges (i.e., from blue to green to orange as [Zn2+] increases in the current case), it also reveals the nuances of rhodamine spirolactam chemistry that have not been sufficiently addressed in the published literature. These issues include the ability of rhodamine spirolactam as a fluorescence quencher via electron transfer, and the slow kinetics of spirolactam ring-opening effected by Zn2+ coordination under pH neutral aqueous conditions.

Kesavapillai Sreenath

Ronald J. Clark

Lei Zhu

Tricolor Emission of a Fluorescent Heteroditopic Ligand over a Concentration Gradient of Zinc(II) Ions

三色发射：荧光异双齿配体在锌(II)离子浓度梯度下的表现

Halogen-bond (XB) catalyzed reactions could also be catalyzed by Brønsted acids, which may complicate the picture of the true activation pathway for these reactions. Herein, we report the first density functional theory study of the mechanistic pathways for the uncatalyzed, iodoimidazolinium halogen bond catalyzed, and a competitive Brønsted acid-catalyzed reduction of quinoline by Hantzsch ester. The uncatalyzed reaction was found to proceed via stepwise pathways. In the lowest energy pathway, proton transfer from Hantzsch ester, a weak Brønsted acid, to quinoline prior to hydride reduction was identified as the key to the lowered energy barriers compared to other reaction pathways. The same reaction steps are involved in the XB-catalyzed pathway, but with substantially lowered reaction barriers, particularly for the hydride-transfer steps. In contrast to the general belief that halogen bond catalysts bind to the electrophile quinoline and activate it by lowering its LUMO energy, we discovered that it is preferable to lower the LUMO energy of quinoline through protonation by Hantzsch ester as a Brønsted acid and stabilize the conjugate anion of Hantzsch ester via halogen bond. Finally, our calculations reveal that the iodoimidazolinium type of catalyst is prone to reduction by Hantzsch ester, generating a Brønsted acid as product. The Brønsted acid catalyzed pathway was calculated to be competitive with the halogen bond catalyzed pathway. Our theoretical findings highlight the need to be cautious when applying iodoimidazolinium catalysts in organocatalysis, and we hope it will aid the design of new halogen bond catalysts that could avoid undesirable Brønsted acid catalysis.

Cher Tian Ser

Hui Yang

Ming Wah Wong

Iodoimidazolinium-Catalyzed Reduction of Quinoline by Hantzsch Ester: Halogen Bond or Brønsted Acid Catalysis

碘咪唑啉鎓盐催化Hantzsch酯还原喹啉：卤键还是Brønsted酸催化

Traditional methods of the α-oxidation of amides often require preactivation or umpolung of amides. In this study, we introduce a general electrochemical approach for the direct α-C(

Yunge Liu

Han Deng

Yunfei Zhang

Electrochemical Umpolung α-Alkoxylation of Thiophene-Containing Amides

噻吩酰胺的电化学反向α-烷氧基化

《有机化学杂志》欢迎有机化学理论和实践所有分支的基础研究的原创性贡献。在选择出版手稿时，编辑们强调作品的质量和新颖性，以及有机化学界的广泛兴趣。

The Journal of Organic Chemistry welcomes original contributions to fundamental research across all branches of theoretical and practical organic chemistry. In selecting manuscripts for publication, the editors emphasize the quality and novelty of the work, as well as its broad interest to the organic chemistry community.

《Journal of Organic Chemistry》欢迎有机化学理论与实践各个领域的原创性基础研究贡献。编辑在选择出版的手稿时，特别强调作品的质量和新颖性，以及其对有机化学界的广泛影响。

Journal of Organic Chemistry

期刊	Journal of Organic Chemistry
ISSN	0022-3263, 1520-6904
h-index	244
Journal Impact	3.32
国际分区	CHEMISTRY, ORGANIC(Q1)
国内分区	化学(2区)化学有机化学(2区)