Yujiro Hayashi of Tokyo University of Science and Teruaki Mukaiyama of the Kitasato Institute developed (Chem. Lett. 2008, 37, 592) a reduction-oxidation method for converting primary, secondary (such as 1, with clean inversion) and tertiary alcohols to sulfides. Peter A. Crooks of the University of Kentucky found (Chem. Lett. 2008, 37, 528) that tetrabenzylpyrophosphate 5 was an effective agent for condensing an acid 4 with an amine 6 to give the amide 7. This protocol, that runs in near quantitative yield in an hour at room temperature, with all impurities readily removable by washing with aqueous base and aqueous acid, appears to be well-suited both for scale-up, and for solid-phase synthesis. Balchandra M. Bhanage of the University of Mumbai reported (Tetrahedron Lett. 2008, 49, 965) the reductive amination of aldehydes, including 8, and ketones to the corresponding amines, using H2 and an inexpensive Fe catalyst. André Charette of the Université de Montréal showed (J. Am. Chem. Soc. 2008, 130, 18) that the Hantzsch ester 12 , in the presence of Tf2O, reduced amides selectively to amines. Esters, epoxides, ketones, nitriles and alkynes were stable to these conditions. Matthew Tudge of Merck Rahway demonstrated (Tetrahedron Lett . 2008, 49, 1041) that Br2 in DME activated NaBH4 , allowing facile reduction of esters, including the congested diester 14, at ambient temperature. David J. Procter of the University of Manchester made (J. Am. Chem. Soc. 2008, 130, 1136) the remarkable observation that six-membered ring lactones such as 16 were reduced to the corresponding diol with SmI2 . Five-membered ring and seven-membered ring lactones were not reduced under these conditions. Bruce H. Lipshutz of the University of California, Santa Barbara devised (Organic Lett . 2008, 10, 289) a convenient and economical procedure for CuH, using Cu and an inexpensive ligand in catalytic amounts, with PMHS as the bulk reductant. The reduction of 18 presumably proceeds by electron transfer, as with dissolving metal reduction, delivering 19 with the more stable trans ring fusion. In the presence of t-BuOH as a proton source, the reduction goes on to the alcohol 20.
SÍNTESE DE NOVOS 1,2,3-TRIAZÓIS INSPIRADOS NO SRPIN340 E AVALIAÇÃO DE SEUS EFEITOS EM LINHAGEM CELULAR DE GLIOBLASTOMA HUMANO