Multiply Substituted Research Articles

Regiodivergent Metal-Controlled Synthesis of Multiply Substituted Quinolin-2-yl- and Quinolin-3-ylphosphonates

In this study, we developed a selective method for synthesis of multi-substituted quinoline-2-ylphosphonates and quinoline-3-ylphosphonates by copper- or gold-catalyzed reactions of phosphoryl-substituted conjugated ynones with 2'-amino-2,2,2-trifluoroacetophenones. The approach proposed makes it possible to obtain various substituted quinolines in good yields. It is also shown that (4,4,4-trifluoro-3-oxobut-1-yn-1-yl)phosphonate reacts with 2-aminoaryl ketones under non-catalytic conditions with formation of 4-substituted quinoline-2-ylphosphonates in high yields.

Efficient Synthesis of Multiply Substituted Triazines Using GO@N-Ligand-Cu Nano-Composite as a Novel Catalyst

GO@N-Ligand-Cu nano-composites were found to function as an efficient catalyst for the synthesis of triazines from benzhydrazides, ammonium acetate, and benzyl derivatives. Graphene-oxide is improved with N,N'-bis(pyridin-2-ylmethyl)benzene-1,2-diamine and after that is matched with copper (Cu). This procedure avoids the use of precious metals and the heterogeneous nature of the GO, on the other hand, the catalyst is easily removed from the product through simple filtration.

Front Cover Picture: Alkynyl−B(dan)s in Various Palladium‐Catalyzed Carbon−Carbon Bond‐Forming Reactions Leading to Internal Alkynes, 1,4‐Enynes, Ynones, and Multiply Substituted Alkenes (Adv. Synth. Catal. 8/2019)

Front Cover Picture: Alkynyl−B(dan)s in Various Palladium‐Catalyzed Carbon−Carbon Bond‐Forming Reactions Leading to Internal Alkynes, 1,4‐Enynes, Ynones, and Multiply Substituted Alkenes (Adv. Synth. Catal. 8/2019)

Alkynyl−B(dan)s in Various Palladium‐Catalyzed Carbon−Carbon Bond‐Forming Reactions Leading to Internal Alkynes, 1,4‐Enynes, Ynones, and Multiply Substituted Alkenes

AbstractIt was found that the C(sp)−B(dan) bond of alkynyl−B(dan)s can be directly used for palladium‐catalyzed carbon−carbon bond‐forming reactions with aryl(alkenyl) halides and allylic carbonates as electrophiles, thus delivering unsymmetrical internal alkynes and unconjugated 1,4‐enynes, respectively. With acyl chlorides as electrophiles, ynone synthesis is also promoted by a palladium catalyst with the assistance of a copper co‐catalyst. These reactions can be achieved as more convenient one‐pot reactions, without isolating the alkynyl−B(dan) formed in situ by the zinc‐catalyzed dehydrogenative borylation of alkynes with HB(dan). In addition to direct C(sp)−B(dan) bond transformations, the C≡C bond in an alkynyl−B(dan) proved to be a promising scaffold for the construction of a multisubstituted alkene, which is synthesized by diboration of the C≡C−B(dan) moiety, leading to a triborylalkene followed by iterative regio‐ and stereoselective Suzuki−Miyaura cross‐coupling reactions. As one example, the synthesis of the ethene with four different aryl groups, p‐MeC6H4, p‐MeOC6H4, p‐NCC6H4, and p‐F3CC6H4, was attained in high overall yield of 64% in six steps starting from the terminal alkyne, p‐MeC6H4C≡CH. Besides these synthetic applications of the alkynyl−B(dan), the scope of the alkynyl substrate in the zinc‐catalyzed dehydrogenative borylation was expanded to enhance the reliability as a provider of the alkynyl−B(dan). Consequently, 42 alkynes were found to participate in the dehydrogenative borylation as substrates; these are alkyl‐, alkenyl‐, aryl‐, heteroaryl‐, ferrocenyl‐, silyl‐, and borylalkynes, with or without a variety of functional groups. Lastly, a new method for preparing HB(dan), as a sulfide‐free, cost‐saving, and reaction‐time‐saving route, is disclosed.magnified image

Three-Component Assembly of Multiply Substituted Homoallylic Alcohols and Amines Using a Flow Chemistry Photoreactor.

Oxadiazolines are bench-stable diazo precursors, which are activated under UV radiation in the presence of vinylboronic acids and aldehydes to enable a one-step three-component assembly of densely functionalized homoallylic alcohols. Substitution on all positions of the homoallylic alcohol product were achieved with high functional group tolerance. No catalyst or other additive was required to effect the reaction, which proceeds at 20 °C over 40 min. Imines and indoles were also incorporated, giving access to homoallylic amines.

Main-Group-Catalyzed Reductive Alkylation of Multiply Substituted Amines with Aldehydes Using H2.

Given the growing demand for green and sustainable chemical processes, the catalytic reductive alkylation of amines with main-group catalysts of low toxicity and molecular hydrogen as the reductant would be an ideal method to functionalize amines. However, such a process remains challenging. Herein, a novel reductive alkylation system using H2 is presented, which proceeds via a tandem reaction that involves the B(2,6-Cl2C6H3)( p-HC6F4)2-catalyzed formation of an imine and the subsequent hydrogenation of this imine catalyzed by a frustrated Lewis pair (FLP). This reductive alkylation reaction generates H2O as the sole byproduct and directly functionalizes amines that bear a remarkably wide range of substituents including carboxyl, hydroxyl, additional amino, primary amide, and primary sulfonamide groups. The synthesis of isoindolinones and aminophthalic anhydrides has also been achieved by a one-pot process that consists of a combination of the present reductive alkylation with an intramolecular amidation and intramolecular dehydration reactions, respectively. The reaction showed a zeroth-order and a first-order dependence on the concentration of an imine intermediate and B(2,6-Cl2C6H3)( p-HC6F4)2, respectively. In addition, the reaction progress was significantly affected by the concentration of H2. These results suggest a possible mechanism in which the heterolysis of H2 is facilitated by the FLP comprising THF and B(2,6-Cl2C6H3)( p-HC6F4)2.

ChemInform Abstract: Synthesis of Multiply Substituted Polycyclic Aromatic Hydrocarbons by Iridium‐Catalyzed Annulation of Ring‐Fused Benzocyclobutenol with Alkyne Through C—C Bond Cleavage.

AbstractA unique and expeditious method for the synthesis of polycyclic aromatic hydrocarbons (26 examples) is developed using an unprecedented Ir‐catalyzed intermolecular cyclization of alkynes with ring‐fused benzocyclobutenols (I).

Synthesis of Multiply Substituted Polycyclic Aromatic Hydrocarbons by Iridium-Catalyzed Annulation of Ring-Fused Benzocyclobutenol with Alkyne through C-C Bond Cleavage.

The first iridium-catalyzed intermolecular cyclization between alkynes and ring-fused benzocyclobutenols (RBCB) through C-C bond cleavage is described. A variety of elusive polycyclic aromatic hydrocarbons (PAHs) with multiple substituents are obtained in good yields under mild conditions. This procedure provides a unique and expeditious tool for the synthesis of PAHs.

Synthesis of Multiply Substituted Polycyclic Aromatic Hydrocarbons by Iridium‐Catalyzed Annulation of Ring‐Fused Benzocyclobutenol with Alkyne through C−C Bond Cleavage

AbstractThe first iridium‐catalyzed intermolecular cyclization between alkynes and ring‐fused benzocyclobutenols (RBCB) through C−C bond cleavage is described. A variety of elusive polycyclic aromatic hydrocarbons (PAHs) with multiple substituents are obtained in good yields under mild conditions. This procedure provides a unique and expeditious tool for the synthesis of PAHs.

ChemInform Abstract: Platinum‐Catalyzed Tandem Cyclization Reaction to Multiply Substituted Indolines under Microwave‐Assisted Conditions.

AbstractThe authors presume that the reaction proceeds via a tandem process involving intramolecular hydroamination of aminoalkynes, Michael addition of enones, aldol condensation, and intermolecular transfer hydrogenation.

Platinum‐Catalyzed Tandem Cyclization Reaction to Multiply Substituted Indolines under Microwave‐Assisted Conditions

AbstractA convenient platinum‐catalyzed tandem cyclization reaction from readily available aminoalkynes and enones has been developed to efficiently prepare multiply substituted indolines in good yields under microwave irradiation within a short reaction time. This efficient reaction is presumed to proceed via a tandem process involving intramolecular hydroamination of aminoalkynes, Michael addition of enones, aldol condensation and intermolecular transfer hydrogenation.magnified image

ChemInform Abstract: Alkyltriflate‐Triggered Annulation of Arylisothiocyanates and Alkynes Leading to Multiply Substituted Quinolines Through Domino Electrophilic Activation.

AbstractThe structures of products (IVb) and (XIIIb) are confirmed by X‐ray analysis.

ChemInform Abstract: One‐Pot Synthesis of Multiply Substituted Quinoline and Quinazoline Derivatives via [2 + 2 + 2] Cascade Annulation with Diaryliodonium Salts.

AbstractA facile protocol is presented for the three‐component reaction of diaryliodonium salts with nitriles and alkynes to give a wide variety of quinoline derivatives.

Alkyltriflate-Triggered Annulation of Arylisothiocyanates and Alkynes Leading to Multiply Substituted Quinolines through Domino Electrophilic Activation

The reaction of arylisothiocyanate, alkyltriflate, and alkynes leads to variously substituted quinolines in high yields. The reaction undergoes alkyltriflate-triggered domino electrophilic activation and avoids the use of a transition-metal catalyst. A variety of functional groups are tolerated in the quinoline ring.

Copper-Mediated Reaction of Zirconacyclopentadienes with Azides: A One-Pot Three-Component Synthesis of Multiply Substituted Pyrroles from One Azide and Two Alkynes

ADVERTISEMENT RETURN TO ISSUEPREVCommunicationNEXTCopper-Mediated Reaction of Zirconacyclopentadienes with Azides: A One-Pot Three-Component Synthesis of Multiply Substituted Pyrroles from One Azide and Two AlkynesYiqing Zhou†, Xiaoyu Yan†, Chao Chen†, and Chanjuan Xi*†‡View Author Information† Key Laboratory of Bioorganic Phosphorus Chemistry & Chemical Biology (Ministry of Education), Department of Chemistry, Tsinghua University, Beijing 100084, People’s Republic of China‡ State Key Laboratory of Elemento-Organic Chemistry, Nankai University, Tianjin 300071, People’s Republic of China*C.X.: tel, +86-10-62782695; e-mail, [email protected]Cite this: Organometallics 2013, 32, 21, 6182–6185Publication Date (Web):October 24, 2013Publication History Received9 October 2013Published online24 October 2013Published inissue 11 November 2013https://doi.org/10.1021/om400988gCopyright © 2013 American Chemical SocietyRIGHTS & PERMISSIONSArticle Views1052Altmetric-Citations14LEARN 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 InReddit Read OnlinePDF (446 KB) Get e-AlertsSupporting Info (1)»Supporting Information Supporting Information SUBJECTS:Azides,Copper,Cyclization,Hydrocarbons,Pyrroles Get e-Alerts

One-Pot Synthesis of Multiply Substituted Quinoline and Quinazoline Derivatives via [2+2+2] Cascade Annulation with Diaryliodonium Salts

An efficient and regioselective method to multisubstituted quinoline and quinazoline derivatives with diaryliodonium salts catalyzed by Cu(OTf)2 has been presented. The reaction proceeded via cascade annulation in the mode of [2+2+2] form. This novel strategy enables use of readily available materials and bears great flexibility on the substitution groups.

ChemInform Abstract: Facile and Controllable Synthesis of Multiply Substituted Benzenes via a Formal [3 + 3] Cycloaddition Approach.

AbstractAn efficient protocol for preparation of di‐ to pentasubstituted benzene derivatives from α,β‐unsaturated carbonyl derivatives and ylides is presented.

Copper(II)‐Catalyzed Three‐Component Cascade Annulation of Diaryliodoniums, Nitriles, and Alkynes: A Regioselective Synthesis of Multiply Substituted Quinolines

Copper(II)‐Catalyzed Three‐Component Cascade Annulation of Diaryliodoniums, Nitriles, and Alkynes: A Regioselective Synthesis of Multiply Substituted Quinolines

Copper(II)‐Catalyzed Three‐Component Cascade Annulation of Diaryliodoniums, Nitriles, and Alkynes: A Regioselective Synthesis of Multiply Substituted Quinolines

A regioselective synthesis of a variety of substituted quinolines is developed using a Cu(II)-catalyzed three-component [2 + 2 + 2] cyclocondensation of diaryliodonium ions, nitriles, and alkynes, whereat the aryl group of the diaryliodonium serves as a C2 building block.

Synthesis of Sequence-Specific Vinyl Copolymers by Regioselective ROMP of Multiply Substituted Cyclooctenes.

A variety of multisubstituted cyclooctenes were prepared and employed as monomers for ring-opening metathesis polymerization using the Grubbs second or third generation catalysts. The resulting polymers were characterized by NMR spectroscopy, size exclusion chromatography, and differential scanning calorimetry. Monomers possessing a substituent at the 3-position afforded highly regio- and stereoregular polyalkenamers, from which the corresponding sequence-specific vinyl quaterpolymers were obtained upon hydrogenation. Simultaneous control of tacticity was also demonstrated by employing monomers with defined stereochemistry.