NEWS OF THE W EEK
TAMING ALKYL OXONIUM IONS
H +
H
O
H
Oxatriquinane
ORGANIC CHEMISTRY: Fused tricyclic
structure stabilizes famously reactive alkylating agents
H +
H
O
H
Oxatriquinacene
A
TEAM OF CHEMISTS from the University
of California, Davis, has synthesized and isolated oxatriquinane and oxatriquinacene, the first water-stable versions of normally highly reactive alkyl oxonium ions (J. Am. Chem. Soc., DOI: 10.1021/ ja805686u). The achievement could lead to a deeper understanding of chemical bonding and reactivity. Alkyl oxonium ions are widely known as reactive intermediates in organic reactions. The few oxonium ions that have been isolated and purified are paired with inert counterions and considered among the most powerful alkylating agents in the laboratory. For example, the commercial reagent trimethyloxonium tetrafluoroborate is so reactive it quickly degrades in water and most organic solvents, even at low temperatures. Associate professor of chemistry Mark Mascal and colleagues at UC Davis synthesized the two water-
SENATE BACKS WIND, SOLAR TAX BREAKS ENERGY: Tax bill’s final fate is unclear,
but drilling ban is lifted for now
T
HE SENATE overwhelmingly passed legisla-
tion last week that would renew and expand tax incentives for wind, solar, and other energy sources as part of a $120 billion, 10-year tax package. Renewable energy firms had long sought the extensions because the current tax breaks terminate at the end of the year. Noting the 93–2 vote, Senate Finance Committee Chairman Max Baucus (DMont.) urged House members “to cut through the noise, come together, and swiftly pass this legislation.” Baucus and Senate Majority Leader Harry Reid (D-Nev.) also warned that House legislative modifications were likely to make Senate pasN EWSCOM
Baucus (left) and Sen. Charles Grassley (R-Iowa) discuss energyrelated tax credits.
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stable alkyl oxonium ions from 1,4,7-cyclononatriene. They found that oxatriquinane does not react with hot water or room-temperature alcohols, alkyl thiols, halide ions, or amine bases. They successfully recorded an NMR spectrum of the oxatriquinane ion in D2O, recrystallized it from water, and purified salts of the ion by column chromatography. Oxatriquinacene, the first stable allylic oxonium ion, is more reactive than oxatriquinane yet significantly more stable than simple alkyl oxonium salts. Mascal attributes the stability of the two ions to their rigid trefoil construction of five-membered rings. “This lack of reactivity would be unheard of for any other oxonium ion,” says Michael M. Haley, a chemistry professor at the University of Oregon. “What we learn at this basic level of science helps us refine our understanding of bonding and reactivity in chemistry.” Thomas W. Bell, a chemistry professor at the University of Nevada, Reno, says, “The discovery is not only a landmark in organic chemistry, it is very significant to many subfields of chemistry and biochemistry.” He adds that the method used in the new study may stabilize other reactive intermediates that cannot be carefully investigated and understood in any other way. Mascal says his group now plans to try stabilizing other reactive molecules such as oxonium ylides and possibly a novel aromatic oxaacepentalene.—RACHEL PETKEWICH
sage impossible if a changed bill returns for approval. However, House leadership was undeterred and split the bill into several parts, signaling their intention to make several changes as C&EN went to press. The Senate bill extends tax incentives for wind energy until the end of 2009 and for solar energy until 2016. The bill’s broad tax provisions affect manufacturers of goods from wooden arrows to plug-in vehicles. It also retroactively reinstates a tax credit that helps fuel billions of dollars of corporate R&D activity in the U.S. The credit, which expired at the end of 2007, can cover up to 20% of qualified R&D spending. Nearly 18,000 U.S. companies typically use the credit, which the Senate bill extends through the end of 2009. Also last week, the House removed a ban on offshore oil and gas drilling that for 27 years has been added to every bill to fund the federal government. A funding bill passed last week as a continuing resolution runs out in March, pushing the drilling debate off until a new Congress and Administration are in place. The ban’s removal had been sought by most Republicans, some Democrats, and oil and chemical companies, which also sought other pro-drilling legislation. But such legislation fell by the wayside as Congress struggled to address the U.S. financial crisis. Despite heated congressional discussion on energy only a few weeks ago (C&EN, Sept. 22, page 14), these bills are likely to be the only energy legislation taken up before Congress members leave to campaign for the November elections.—JEFF JOHNSON
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