NEWS OF THE WEEK
CAPSULE CHEMISTRY SYNTHESIS: Paraffin capsules preloaded with air-sensitive reagents free chemists from the glove box
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handle air- and moisture-sensitive reagents knows the experience is something akin to playing piano in boxing gloves. To make it easier to work with such compounds, chemists at MIT have devised paraffin capsules that can hold premeasured doses of chemicals and be dropped into reaction vessels outside the glove box (Nature 2015, DOI: 10.1038/nature14654). The group, led by chemistry professor Stephen L. Buchwald, was inspired by work from University of Delaware chemistry professor Douglass F. Taber. More than 10 years ago, Taber invented a uniform dispersion of oxygen- and moisture-sensitive reagents such as potassium hydride in paraffin wax that can be added to solutions. When heated, the wax melts, releasing the reagent into solution. The paraffin doesn’t interfere NAT U R E
A paraffin capsule created in the Buchwald lab.
NYONE WHO’S ever had to use a glove box to
MERGERS SWEEP FERTILIZER SECTOR AGRICULTURE: CF to merge with OCI,
Rentech and CVR get together
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in the fertilizer industry. CF Industries will strengthen its leading position in nitrogen fertilizers with the purchase of plants in North America and beyond from the Dutch firm OCI. CVR Partners will acquire a facility from Rentech Nitrogen. And PotashCorp continues a hostile bid for Germany’s K+S. CF is paying $8 billion in cash, stock, and assumed debt for the OCI assets. For that price CF will get OCI’s massive nitrogen complex in Geleen, the Netherlands; a large fertilizer plant in Wever, Iowa; and an ammonia/methanol plant in Beaumont, Texas. It will also acquire OCI’s distribution business and a 45% interest in Natgasoline, a methanol project under construction in Beaumont. OCI will hold on to fertilizer plants CF INDUSTRIES
CF’s distribution terminal in Blair, Neb.
RASH OF CONSOLIDATION has broken out
CEN.ACS.ORG
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with reactions and can be removed from mixtures via filtration and chromatography. But when Buchwald and coworkers tried a similar approach with reagents for an aryl fluorination reaction, they weren’t able to get a uniform dispersion of the chemicals in the wax. That’s when they hit upon the idea of creating a capsule with preloaded amounts of reagents. To create the capsules, one simply dips the end of a glass stir rod into melted paraffin several times to create a hollow tube with one sealed end. Once the openended wax capsule cools, it can be removed, loaded with reagents, and sealed at the other end with a heated metal spatula, describes postdoc Aaron C. Sather, who came up with the capsule-creating technique. At the moment, the method doesn’t entirely unchain chemists from the glove box. After all, the reagents must be loaded into the capsules in an inert atmosphere. But Buchwald envisions that such capsules will eventually be commercially available. “It simplifies things, and it prevents a lot of waste,” he says. “It is particularly exciting that some of these capsules have been shown to maintain activity for many months under ambient conditions,” Taber comments. Indeed, the MIT chemists demonstrate that the capsules can sit on a benchtop for more than a year in some instances and can even be submerged in water overnight without losing their potency.—BETHANY HALFORD
in Algeria and Egypt. It will also keep the recently purchased BioMCN methanol facility in the Netherlands and a 55% interest in Natgasoline. Meanwhile, CVR’s deal with Rentech Nitrogen is worth $533 million, also in cash and equity. CVR will get Rentech’s East Dubuque, Ill., nitrogen fertilizer plant, creating the fifth-largest nitrogen supplier in North America. Anders Isberg, an analyst with the consultancy CRU Group, says the mergers are likely the consequence of uncertain times in the fertilizer industry. Nitrogen markets are oversupplied, he says, and prices have been declining. For CF, the OCI acquisition will help navigate these choppy waters. For instance, buying the Wever plant knocks out a low-cost competitor in the middle of the U.S. corn belt. CF also will benefit from a beachhead in Europe with the Dutch plant and will establish itself in methanol. Similarly, CVR is acquiring a facility with easy access to Midwestern farmers. Rentech claims the East Dubuque plant is one of the most profitable in North America. The fertilizer consolidation isn’t relegated to nitrogen products. PotashCorp is attempting to take over Germany’s K+S to get its hands on the company’s German potash assets and a potash project in Saskatchewan. However, K+S shareholders have thus far rejected the unsolicited proposal.—ALEX TULLO
AUGUST 17, 2015
