Science Concentrates SYNTHESIS
Azides safely used to synthesize diamines salts directly without having to purify the diazides. “1,2-Vicinal diamines represent a common scaffold found in many small molecules and a useful building block to cyclic olefins to diamines at room temAcademic researchers often develop synthetic organic chemists,” says Angela perature using trimethylsilyl azide, a organic synthesis methods that offer Puchlopek-Dermenci, principal scientist benziodoxole oxidizing reagent, and an efficient new routes to industrially imin chemical research and development at iron catalyst with a tridentate ligand portant chemicals. But many of these (Angew. Chem. Int. Ed. 2015, DOI: 10.1002/ Pfizer and an associate editor of Organic methods are considered untouchable in Process Research & Development, which anie.201507550). The reaction drew the an industry setting because they involve published the new study. But azidation of attention of industrial chemists as a genhazardous reagents that can’t be safely olefins commonly used + (CH3)3SiN3 to prepare them is ofO H3N R1 N3 R1 ten avoided in industry 1 3 3 R R R Iron catalyst because of the hazards R3 PPh3, CH3C6H4SO2H O R2 + 2 R Room temperature of handling azides and + I NH3 R2 N3 diazides, she explains. OH C6H4SO2– 2 CH “The new approach 3 Olefin Diazide is consistent with inBenziodoxole oxidant intermediate Diaminium salt dustry best practices for safely using energetic compounds,” eral approach for producing diamines, handled on a larger scale or because they Puchlopek-Dermenci adds. “In this case, Xu tells C&EN. This interest led to the are cost-prohibitive to implement. Somethe researchers demonstrate through trans-Atlantic partnership to explore the times, though, a success story does come process safety testing the utility of this possibility of large-scale applications. along. iron-catalyzed olefin diazidation method The collaboration with Redox LaboAn industry-academic collaboration as a rapid, yet safe and scalable, way to ratory involved a safety assessment of led by Hao Xu of Georgia State Uniaccess this useful class of compounds.” the reagents, diazide intermediates, and versity and Marino Nebuloni of Italian Xu says the new chemical process product diaminium salts. The assessspecialty chemical company Redox for pharmaceutical production is bement revealed that the most problematic Laboratory has developed a gram-scale ing patented by Georgia State, and the compounds, the diazide intermediates, procedure for directly adding azides collaborative team plans to report a are thermally stable but moderately to olefins to make vicinal primary disecond-generation method that is more shock-sensitive, and that the diaminium amines (Org. Process Res. Dev. 2017, DOI: environmentally friendly and tailored salts made from them are more stable. 10.1021/acs.oprd.7b00312). for deactivated substrates as well as Guided by that knowledge, the team opXu’s group first reported the functionalized olefins and N-heterocytimized the procedure to develop a grammild-mannered method in late 2015, cles.—STEVE RITTER scale reaction to produce diaminium converting unfunctionalized linear and
COATINGS
Modified sponge mops up oil but not water In an effort to provide a cheap, reusable method to clean up water after oil and chemical spills, Tanmay Das and Debasish Haldar of the Indian Institute of Science Education & Research, Kolkata, coated a polystyrene sponge with a compound that allows it to absorb oil and a wide range of organic solvents but not water (ACS Omega 2017, DOI: 10.1021/acsomega.7b01379). Watch a video (screen shot at right) of the oil-mopping sponge in action at cenm.ag/oilwatersponge.—KERRI JANSEN
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C&EN | CEN.ACS.ORG | DECEMBER 4, 2017
CR E DI T: D. H AL DA R /ACS OM EGA /C& E N
Industry-academic team develops a mild method for handling the hazardous reagents
