Microwave-Assisted Continuous-Flow Organic Synthesis Research Articles

Metal Nanoparticle Impregnated Controlled-size Silica Macrospheres as a Microwave-transparent Catalyst System for MACOS

Background: Metal films in microwave-assisted, continuous-flow organic synthesis (MACOS) have shown to act as heterogeneous catalysts for a variety of reactions, but have difficulty due to difficult to control heating and occurrence of laminar flow which limits the contact of the reagents with the catalyst surface. The aim of this paper is to describe a microwave-transparent supported metal catalyst with high surface area and its use in MACOS. Methods: Millimeter sized, monodisperse, macroscopic spherical silica beads loaded with Ni, Cu, and Pd nanoparticles were prepared through use of a single-step emulsion procedure via a sol-gel process and used to perform Heck cross-coupling reactions in MACOS. Results: The size of the spheres was readily controlled to a maximum diameter of 1300 m by varying the stirring rate of the emulsion mixture. Pd loadings of up to 4.3 wt.% were obtained, and confirmed to be present as nanoparticles through PXRD spectroscopy and TEM imaging. The metal-loaded spheres were found to be essentially microwave-transparent, allowing for use as catalytic beads in microwave flow reactors. In addition, no mechanical dislodgement of the nanoparticles or degradation of their catalytic activity was observed over repeated usage. Conclusion: Metal-nanoparticle-impregnated silica macrospheres were found to be an effective catalyst for use in MACOS by providing access to the use of heterogeneous metal catalysts with controllable heating. Further testing of various metals and reactions can be performed to increase the scope of possible reactions to be catalysed in MACOS using metal-impregnated macrospheres as catalysts. Keywords: Catalyst, flow chemistry, MACOS, microwave, nanoparticle.

ChemInform Abstract: Microwave‐Assisted Continuous Flow Organic Synthesis (MACOS)

AbstractReview: 82 refs.

ChemInform Abstract: Synthesis of an Isoindoline‐Annulated, Tricyclic Sultam Library via Microwave‐Assisted, Continuous‐Flow Organic Synthesis (MACOS).

AbstractA reaction sequence involving three consecutive microwave‐promoted continuous‐flow reaction steps is presented to synthesize the title compounds (V) and (VII).

Multicapillary Flow Reactor: Synthesis of 1,2,5-Thiadiazepane 1,1-Dioxide Library Utilizing One-Pot Elimination and Inter-/Intramolecular Double aza-Michael Addition Via Microwave-Assisted, Continuous-Flow Organic Synthesis (MACOS).

A microwave-assisted, continuous-flow organic synthesis (MACOS) protocol for the synthesis of functionalized 1,2,5-thiadiazepane 1,1-dioxide library, utilizing a one-pot elimination and inter-/intramolecular double aza-Michael addition strategy is reported. The optimized protocol in MACOS was utilized for scale-out and further extended for library production using a multicapillary flow reactor. A 50-member library of 1,2,5-thiadiazepane 1,1-dioxides was prepared on a 100- to 300-mg scale with overall yields between 50 and 80% and over 90 % purity determined by proton nuclear magnetic resonance (1H-NMR) spectroscopy.

Synthesis of an Isoindoline-Annulated, Tricyclic Sultam Library via Microwave-Assisted, Continuous-Flow Organic Synthesis (MACOS)

A microwave-assisted, continuous-flow organic synthesis (MACOS) protocol for the synthesis of an isoindoline-annulat-ed, tricyclic sultam library, utilizing a Heck-aza-Michael (HaM) strategy, is reported. This sequence involves a Heck reaction on vi-nylsulfonamides with batch microwave heating followed by a one-pot, sequential intramolecular aza-Michael cyclization/Boc-deprot-ection using MACOS. Subsequent cyclization with either 1,1'-carbonyldiimidazole or chloromethyl pivalate using MACOS provided an array of tricyclic sultams. This efficient three-step protocol requires only a few hours to produce the target sultams starting from simple starting materials. Using this strategy, a 38-member library of isoindoline-annulated sultams was generated in good to excellent overall yields (53-87%).

The development of a general strategy for the synthesis of tyramine-based natural products by using continuous flow techniques.

The development of a general strategy for the synthesis of tyramine-based natural products by using continuous flow techniques.

Scaling Out by Microwave‐Assisted, Continuous Flow Organic Synthesis (MACOS): Multi‐Gram Synthesis of Bromo‐ and Fluoro‐benzofused Sultams Benzthiaoxazepine‐1,1‐dioxides

Scaling Out by Microwave‐Assisted, Continuous Flow Organic Synthesis (MACOS): Multi‐Gram Synthesis of Bromo‐ and Fluoro‐benzofused Sultams Benzthiaoxazepine‐1,1‐dioxides

ChemInform Abstract: Propargyl Amine Synthesis Catalyzed by Gold and Copper Thin Films by Using Microwave‐Assisted Continuous‐Flow Organic Synthesis (MACOS).

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

Propargyl Amine Synthesis Catalysed by Gold and Copper Thin Films by Using Microwave‐Assisted Continuous‐Flow Organic Synthesis (MACOS)

An effective multi-component reaction (MCR) protocol has been developed for the construction of propargyl amines from aldehydes, amines and terminal alkynes by using microwave-assisted continuous-flow organic synthesis (MACOS). The process is catalysed by thin films of either copper or gold that achieve temperatures in excess of 900 degrees C when irradiated with low levels of microwave power. The process works equally well for premixed solutions of the three starting materials, or as three separate streams, which improves the combinatorial efficiency of the method. The process tolerates a wide variety of functional groups and heterocycles, and conversion over these diverse substrates ranges from 70-90 %.

Inside Cover: Propargyl Amine Synthesis Catalysed by Gold and Copper Thin Films by Using Microwave‐Assisted Continuous‐Flow Organic Synthesis (MACOS) (Chem. Eur. J. 1/2010)

Inside Cover: Propargyl Amine Synthesis Catalysed by Gold and Copper Thin Films by Using Microwave‐Assisted Continuous‐Flow Organic Synthesis (MACOS) (Chem. Eur. J. 1/2010)

Editorial: Crystal‐Clear View of Chemistry

Editorial: Crystal‐Clear View of Chemistry

Gold film-catalysed benzannulation by microwave-assisted, continuous flow organic synthesis (MACOS).

Methodology has been developed for laying down a thin gold-on-silver film on the inner surface of glass capillaries for the purpose of catalysing benzannulation reactions. The cycloaddition precursors are flowed through these capillaries while the metal film is being heated to high temperatures using microwave irradiation. The transformation can be optimized rapidly, tolerates a wide number of functional groups, is highly regioselective, and proceeds in good to excellent conversion.

ChemInform Abstract: Gold‐Film‐Catalyzed Hydrosilylation of Alkynes by Microwave‐Assisted, Continuous‐Flow Organic Synthesis (MACOS).

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

Gold‐Film‐Catalysed Hydrosilylation of Alkynes by Microwave‐Assisted, Continuous‐Flow Organic Synthesis (MACOS)

Thin gold films on the surface of glass capillaries have proven to be highly active catalysts for the rapid hydrosilylation of alkynes that are flowed through the reactor while being heated by microwave irradiation. The films are able to be reused at least five times with no loss of activity and with no detectable levels of gold showing up in the hydrosilylated products.

ChemInform Abstract: Diels—Alder Cycloadditions by Microwave‐Assisted, Continuous Flow Organic Synthesis (MACOS): The Role of Metal Films in the Flow Tube.

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

Diels–Alder cycloadditions by microwave-assisted, continuous flow organic synthesis (MACOS): the role of metal films in the flow tube

Thin Pd films have been deposited on the inside of capillary-sized tubes through which compounds undergoing Diels-Alder reactions have been flowed while being heated with microwave irradiation; dramatic rate accelerations are observed in the presence of the film, which has been shown to play both a heating and catalytic role.

Multicomponent Reactions to Form Heterocycles by Microwave-Assisted Continuous Flow Organic Synthesis

ADVERTISEMENT RETURN TO ISSUEPREVReportNEXTMulticomponent Reactions to Form Heterocycles by Microwave-Assisted Continuous Flow Organic SynthesisW. Stacy Bremner and Michael G. OrganView Author Information Department of Chemistry, York University, 4700 Keele Street, Toronto, Ontario, Canada, M3J 1P3 Cite this: J. Comb. Chem. 2007, 9, 1, 14–16Publication Date (Web):November 17, 2006Publication History Received18 September 2006Published online17 November 2006Published inissue 1 January 2007https://doi.org/10.1021/cc060130pCopyright © 2007 American Chemical SocietyRIGHTS & PERMISSIONSArticle Views2126Altmetric-Citations100LEARN 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 (29 KB) Supporting Info (1)»Supporting Information Supporting Information SUBJECTS:Chemical reactions,Chemical synthesis,Electromagnetic radiation,Irradiation,Organic synthesis Get e-Alerts

Catalysis in Capillaries by Pd Thin Films Using Microwave‐Assisted Continuous‐Flow Organic Synthesis (MACOS).

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.

Catalysis in Capillaries by Pd Thin Films Using Microwave‐Assisted Continuous‐Flow Organic Synthesis (MACOS)

Catalysis in Capillaries by Pd Thin Films Using Microwave‐Assisted Continuous‐Flow Organic Synthesis (MACOS)

Catalysis in Capillaries by Pd Thin Films Using Microwave‐Assisted Continuous‐Flow Organic Synthesis (MACOS)

Catalysis in Capillaries by Pd Thin Films Using Microwave‐Assisted Continuous‐Flow Organic Synthesis (MACOS)