Section II: chemistry Bailey Science Center, room 1024 Zewdu Gebeyehu, presiding.
3:30 SYNTHESIS OF CHIRAL [MINES AND AMINES ON SILICA SURFACES, R. Tomlinson *, J. Baker. S. Booth. J. Brock. M. Patel, C. Perryman and J.T. Barbas. Valdosta State University, Valdosta, GA 31698. Recently we have been investigating "greener-methods for the synthesis of aromatic benzodiazines, chiral imines and chiral amines. We have discovered that we can synthesize these compounds in tandem, in one pot, at ambient temperatures, in quantitative yields. Furthermore, our syntheses take place in minutes, use little solvent, and are economical. Typically, 2 g of activated silica, are added to an anhydrous solution of equimolar quantities (2 x [10.sup.3] mol) of an aldehyde and a primary chiral amine. The reaction is monitored by GC-MS and takes only a few minutes for the complete formation of the imine. To this solution, 0.15 g of sodium borohydride are added and stirred briefly. The solution is cooled in an ice bath and a few drops of water are added periodically to complete the reduction of the imine. In turn, the mixture is filtered, the silica washed several times with anhydrous ether, and the extracts combined and dried over anhydrous sodium sulfate. The ether is removed under vacuum to yield pure chiral amines. The products are analyzed by IR. GC-MS, and proton and C-13 NMR, and polarimetry.
3:45 LEWIS ACID CATALYZED 2.3-REARRANGMENTS OF O-ALLYLHY-DROXYLAMINES **. J. C. Lord *, H. F. Lee *, J. M. Baxter Vu, Valdosta State University, Valdosta, GA 31698. While chiral carbinamines are common pharmacophores, a green, rapid. and economical construction of these small molecules remains a challenge to the synthetic chemist. This work focuses on the formation of tertiary carbinamine centers via a 2,3-rearrangement of hydroxylamine allyl ethers. After screening a variety of Lewis and Bronsted acids, we have developed a silver trifluromethanesulfonate promoted 2,3-rearrangement of O-a Ilyihydroxylamines. This Lewis acid catalyzed rearrangement offers several advantages over current technology: 1) it lends itself towards developing an asymmetric variant of this transformation via the use of a chiral Lewis acid or a metal salt with chiral ligand additives, 2) the exclusion of n-BuLi to promote the reaction will result in a broader substrate scope by allowing acidic or electrophilic functional groups to be present in the molecule, and 3) this rearrangement is an environmentally friendly alternative to the Overman rearrangement.
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|Title Annotation:||FRIDAY PAPER PRESENTATIONS|
|Publication:||Georgia Journal of Science|
|Article Type:||Conference notes|
|Date:||Mar 22, 2013|
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