EXPANDING ON HYDROAMINATIONS - C&EN Global Enterprise

Jan 21, 2008 - A RHODIUM CATALYST system conjured up by Zhijian Liu and John F. Hartwig of the University of Illinois, Urbana-Champaign, can catalyze ...
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NEWS OF THE W EEK

REPORT INDICATES DECLINE IN U.S. R&D STATISTICS: Falloff of industry and government support for basic research raises competitiveness concerns

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the federal government and by industry raise serious questions about the ability of the U.S. to remain competitive in a rapidly changing world. This is one of the conclusions from the latest “Science & Engineering Indicators” report from the National Science Board (NSB), the policy-making body for the National Science Foundation. “These indicators come at an important time,” NSB Chairman Steven C. Beering said at a Jan. 15 press briefing on the report. “The confluence of a range of indicators raises key questions about future U.S. high-technology industry’s competitiveness in international markets and implications for highly skilled jobs at home.” The indicators report is a massive collecDAVID HA NSON/C & EN

Reilly holds up NSB’s analysis and policy recommendations.

ECLINES IN SUPPORT for basic research by

EXPANDING ON HYDROAMINATIONS ORGANIC SYNTHESIS: Rhodium

catalyst broadens scope of intramolecular cyclizations

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RHODIUM CATALYST system conjured up

by Zhijian Liu and John F. Hartwig of the University of Illinois, Urbana-Champaign, can catalyze intramolecular cyclizations of aminoalkenes under mild conditions (J. Am. Chem. Soc., DOI: 10.1021/ ja710126x). The reaction, when optimized, could significantly expand the scope of hydroaminations of olefins, one of the simplest ways to prepare alkylamines. The reactions proceed with unactivated aminoalkenes containing primary NEW ACCESS Adding secondary amines to or secondary internal alkenes is one capability of the new amines, termihydroamination system. nal or internal Rhodium amino H alkenes, and biarylphosphine Ph N linkers that posCH3 catalyst N CH3 Ph sess or lack subPh stituents that Ph bias the subPh = phenyl strate toward WWW.C E N- ONLI NE .ORG

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tion of data on all areas that impact R&D conducted by universities, industry, and government. Major sections of this year’s report provide data on science and technology education, the scientific labor force, international R&D trends, and public understanding of science. NSB member Arthur K. Reilly spoke at the report’s release particularly about industry shifts during the past few years. He noted that not only has industrial support for academic research been declining, but industry-authored journal publications are falling, too. “Perhaps industrial researchers have other priorities,” Reilly said, and he noted that NSB urges more collaboration between university and industry scientists. But it’s not all bad news for R&D in the U.S. According to the report, intellectual property value, science and engineering education, and high-technology manufacturing are among the areas where the U.S. does extremely well. NSB published a separate analysis of areas in which trends are particularly troubling, along with several policy recommendations. The recommendations call for the federal government to improve funding for basic research; for industry, government, and academia to seek greater intellectual interchange; and for the government to develop new ways to measure the changes caused by the rapid globalization of manufacturing and their implications for the U.S.—DAVID HANSON

cyclization. In addition, the reactions occur at low temperature and aren’t disrupted by spectator functional groups. That diverse combination of possibilities, which is not matched by existing catalyst systems, leads to a variety of five- and six-membered-ring products, the researchers note. University of Michigan chemist Melanie S. Sanford, whose work has included rhodium-mediated cyclizations, comments that Liu and Hartwig’s hydroamination results “address an important problem in organic synthesis that had not been previously solved.” A lot of progress had already been made in developing catalytic processes for hydroaminations, which involve the addition of an N–H bond across the multiple bond of an alkene, allene, or alkyne. Lanthanides, group 4 early-transition metals, and some late-transition metals have been reported to add amines to olefins, Hartwig says, but those catalysts have been limited in one way or another. In some cases, the metals are too sensitive to air or moisture. In other cases, the metals only facilitate additions involving secondary amines or terminal olefins. And in yet other cases, the metals can’t tolerate the presence of polar functional groups. Liu and Hartwig created their catalyst by combining the precursor [Rh(cyclooctadiene)2]BF4 with a variety of arylphosphine ligands that permitted them to control the selectivity of the reactions. They focused on an amino biarylphosphine ligand, which converted a range of aminoalkenes to pyrrolidines and piperidines and Nsubstituted pyrrolidines and piperidines.—STEVE RITTER

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