GreenCentre Canada

Kingston, Canada

GreenCentre Canada

Kingston, Canada

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The present application provides precursor compounds useful for deposition of a group 11 metal on a substrate, for example, a microelectronic device substrate, as well as methods of synthesizing such precursor compounds. The precursor compounds provided are mono-metallic compounds comprising a diaminocarbene (DAC) having the general formula: DAC-M-X, where the diaminocarbene is an optionally substituted, saturated N-heterocyclic diaminocarbene (sNHC) or an optionally substituted acyclic diaminocarbene, M is a group 11 metal, such as copper, silver or gold; and X is an anionic ligand. Also provided are methods of synthesizing the precursor compounds, metal deposition methods utilizing such precursor compounds, and to composite materials, such as, e.g., microelectronic device structures, and products formed by use of such precursors and deposition methods.


Collaborations between chemists in academia and in the pharmaceutical industry have yielded two new tools that scientists can use to make important modifications to drug candidates. One of the tools will help scientists studying a compound’s breakdown in the body and its biological target. The other will help medicinal chemists looking to make novel analogs of certain molecules. Chemists in Paul J. Chirik’s group at Princeton University and at Merck & Co. report an iron catalyst that swaps hydrogens on aromatic compounds for tritiums in the presence of tritium gas (Nature 2016, DOI: 10.1038/nature16464). By tracking the resulting radioactive tritiated compounds in cells and in animals, ­scientists can zero in on a drug candidate’s ­biological target as well as how it gets ­metabolized. Chirik tells C&EN that a student in his group was actually working with the catalyst on an entirely different transformation when, during a visit from Merck scientists, a process chemist asked whether the student had tried a deuterium-labeling experiment with deuterium gas. The student responded that such isotope-labeling experiments were problematic because the catalyst tended to put the isotope on the toluene solvent. The Merck chemist realized that the iron catalyst could do C–H exchange with aromatics and might therefore be a boon for tritium labeling. Previous examples of catalysts that do this type of C–H exchange use iridium and usually rely on directing groups to guide where the tritium goes. This new catalyst swaps tritium for the least hindered aromatic hydrogens in a molecule, giving radiochemists the ability to label alternative spots. “The new iron catalyst gives the radiochemist another valuable single-step method to add to the toolbox and increases the number of pharmaceutical structures that can be tritium-labeled in a single rapid step,” notes David Hesk, a Merck radiochemist who worked on the project. “Chirik’s group has identified an iron catalyst system that operates in a thoroughly complementary manner to the iridium catalysts that dominate the field,” comments William J. Kerr, an expert in isotopic-labeling methods at the University of Strathclyde. Kerr adds that the catalyst’s substrate and solvent compatibility make it particularly attractive. If researchers can improve the iron catalyst’s stability and handling, he says, it’s likely to be widely ­adopted. To that end, Chirik tells C&EN that his group is working with GreenCentre Canada to make the iron complex commercially ­available. Chemists in Phil S. Baran’s group at Scripps Research Institute California and at Pfizer also report novel chemistry that will help medicinal chemists. Specifically, it will help scientists looking to quickly synthesize an array of molecules that contain small, strained rings. They have developed a general strategy for opening “spring loaded” C–C and C–N bonds in strained-ring systems with amines (Science 2016, DOI: 10.1126/science.aad6252). The method, known as strain-release amination, relies on breaking a strained C–C or C–N bond with a turbo-amide, thereby tacking propellerlike bicyclo[1.1.1]pentanes as well as cyclobutanes and azetidines onto amines. Such molecules can have beneficial properties, such as improved metabolic stability. The reaction tolerates a broad range of functional groups, so it can be done even in the late stages of a synthetic route. John P. Maxwell, director of medicinal chemistry at Vertex Pharmaceuticals, notes that the strategy is attractive to both medicinal and process chemists. “Late-stage functionalization is a desirable approach in certain instances, and this work gives some new ways to think about and achieve it,” he says. Baran tells C&EN that Pfizer initially approached him to see whether his group could help the firm with the synthesis of bicyclo[1.1.1]pentan-1-amine, a critical component of a clinical candidate the pharma chemists were having trouble securing in the quantities they needed. Without the new strain-release amination chemistry, it’s likely the clinical candidate would have been abandoned, Baran notes. “If you can do fundamental science, that’s great. If you can do applied science, that’s great,” Baran says. “But if you can do both, where you can see the pathway from flask to a patient in the hospital, that’s the most exciting research you can do.”


The type of biosensor they are using in the research is used in virtually every hospital in the developed world. The coatings will increase the robustness of medical instruments used in hospitals around the world and will also be used for corrosion resistance for metals. "Previously the technique used to apply these coatings required access to specialized equipment," says Dr. Crudden. "We have now designed a simple process for applying the coatings without any specialized equipment, making the application process accessible to everyone." This new technique builds on an earlier discovery in 2014 when the research trio developed a technique to prepare single molecule-thick coatings of organic molecules on the surface of metals. Despite being 100,000 times thinner than a human hair, this layer is able to withstand a battery of harsh chemicals, oxidants, acids and bases - a discovery that has positive implications for the microelectronics industry (an industry devoted to the design and development of tiny electronic devices). The recent discovery allows the coating to be applied without the use of specialized equipment therefore making it more accessible. Working with GreenCentre Canada, Drs. Crudden, Horton and McLean hope to make this a reality so that researchers world-wide can access this new technology. The research was published in Nature Communications. Explore further: Researchers patent process that binds organic compounds to metal surfaces More information: Cathleen M. Crudden et al. Simple direct formation of self-assembled N-heterocyclic carbene monolayers on gold and their application in biosensing, Nature Communications (2016). DOI: 10.1038/ncomms12654


Jessop P.G.,Queen's University | Kozycz L.,Queen's University | Rahami Z.G.,Queen's University | Schoenmakers D.,Queen's University | And 3 more authors.
Green Chemistry | Year: 2011

Several tertiary amines serve as switchable-hydrophilicity solvents, meaning that they are hydrophobic solvents having very low miscibility with water when under air but hydrophilic solvents having complete miscibility with water when under an atmosphere of CO 2. Unlike the only previously reported switchable-hydrophilicity solvent, these amines are easily prepared and, in some cases, commercially available. The effect of temperature, gas flow rates, choice of amine and additives on the switching process is described. These solvents can be applied to the recycling of polystyrene foam. © The Royal Society of Chemistry.


Thomson J.W.,GreenCentre Canada | Hatnean J.A.,University of Toronto | Hastie J.J.,GreenCentre Canada | Pasternak A.,GreenCentre Canada | And 2 more authors.
Organic Process Research and Development | Year: 2013

A modified process using inexpensive poison scavengers has been developed that allows for more economical and practical scale-up of metal-free catalytic hydrogenation. The scavengers remove impurities such as water and aldehydes that can hinder catalysis allowing for the use of commercial-grade solvents, substrates and gases. In addition, the scavengers have the unique ability to regenerate poisoned catalysts, allowing for increased turnover numbers and longer catalyst lifetimes. Hydrogenations of unpurified imine substrates proceed with high yield using a variety of metal-free hydrogenation catalysts, demonstrating the general compatibility of this process. © 2013 American Chemical Society.


Patent
Greencentre Canada and Queen's University | Date: 2013-11-08

A solvent that reversibly converts from a hydrophobic liquid form to hydrophilic liquid form upon contact with water and a selected trigger, e.g., contact with CO_(2), is described. The hydrophilic liquid form is readily converted back to the hydrophobic liquid form and water. The hydrophobic liquid is an amidine or amine. The hydrophilic liquid form comprises an amidinium salt or an ammonium salt.


Patent
Queen's University and Greencentre Canada | Date: 2014-09-18

The present application provides a composite material that comprises a solid and solid-supported non-polymeric switchable moiety, wherein the switchable moiety comprises a functional group that is switchable between a first form and a second form, said first form being neutral and hydrophobic, and said second form being ionized and hydrophilic. The composite material converts to, or is maintained in, said second form when the switchable moiety is exposed to CO_(2 )at amounts sufficient to maintain the ionized form. The composite material converts to, or is maintained in, said first form when CO_(2 )is removed or reduced to an amount insufficient to maintain the ionized form. CO_(2 )is removed or reduced by exposing the composite material to heat and/or a flushing inert gas such as N_(2), Ar, or air. Envisioned uses of these composite materials includes removing water from non-aqueous solvents, removing water vapour from gaseous mixtures, and cleaning industrial reaction vessels and/or pipelines.


Patent
Queen's University and Greencentre Canada | Date: 2014-10-24

A solvent that reversibly converts from a hydrophobic liquid form to hydrophilic liquid form upon contact with water and a selected trigger, e.g., contact with CO_(2), is described. The hydrophilic liquid form is readily converted back to the hydrophobic liquid form and water. The hydrophobic liquid is an amidine or amine. The hydrophilic liquid form comprises an amidinium salt or an ammonium salt.


Patent
Greencentre Canada | Date: 2013-03-13

The present application provides salen indium catalysts of the following general structure and the corresponding dimers. The salen indium catalysts are particularly useful in catalyzing ring-opening polymerizations of cyclic ester monomers, such as lactides. Also provided herein are methods of using the salen indium complexes to catalyze polymerization of cyclic ester monomers. Of particular interest is the successful polymerization of lactides using the present salen indium catalysts to produce poly(lactic acid) having high isotacticity.


Patent
University of Ottawa and Greencentre Canada | Date: 2012-11-23

The present application provides compound of Formula X wherein A is an optionally substituted aliphatic or an optionally substituted aryl, and B is a moiety that stabilizes the partial positive charge at the carbon adjacent the divalent sulfur. The compound of Formula X is useful as a reversible antioxidant in a variety of applications. Also provided are methods of synthesizing the compound of Formula X.

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