Functional Group Interconversion
Glenn M. Sammis at the University of British Columbia reported (Angew. Chem. Int. Ed. 2012, 51, 10804. ) the photo-fluorodecarboxylation of aryloxyacids such as 1 using Selectfluor 2. Jean-François Paquin at the Université Laval found (Org. Lett. 2012, 14, 5428. ) that the halogenation of alcohols (e.g. 4 to 5) could be achieved with [Et2NSF2]BF4 (XtalFluor-E) in the presence of the appropriate tetraethylammonium halide. A method for the reductive bromination of carboxylic acid 6 to bromide 7 was developed (Org. Lett. 2012, 14, 4842. ) by Norio Sakai at the Tokyo University of Science. Prof. Sakai also reported (Org. Lett. 2012, 14, 4366. ) a related method for the reductive coupling of acid 8 with octanethiol to produce thioether 9.
The esterification of primary alcohols in water-containing solvent was achieved (Org. Lett. 2012, 14, 4910. ) by Michio Kurosu at the University of Tennessee Health Science Center using the reagent 11, such as in the conversion of alcohol 10 to produce 12 in high yield. Hosahudya N. Gopi discovered (Chem. Commun. 2012, 48, 7085. ) that the conversion of thioacid 13 to amide 14 was rapidly promoted by CuSO4.
A ruthenium-catalyzed dehydrative amidation procedure using azides and alcohols, such as the reaction of 15 with phenylethanol to produce 16, was reported (Org. Lett. 2012, 14, 6028. ) by Soon Hyeok Hong at Seoul National University. An alternative oxidative amidation was developed (Tetrahedron Lett. 2012, 53, 6479. ) by Chengjian Zhu at Nanjing University and the Shanghai Institute of Organic Chemistry who utilized catalytic tetrabutylammonium iodide and disubstituted formamides to convert alcohols such as 17 to amides 18.
A redox catalysis strategy was developed (Angew. Chem. Int. Ed. 2012, 51, 12036. ) by Brandon L. Ashfeld at Notre Dame for the triphenylphosphine-catalyzed Staudinger ligation of carboxylic acid 19 to furnish amide 20. For direct catalytic amidation of carboxylic acids and amines such as in the conversion of 21 to 23, Dennis G. Hall at the University of Alberta reported (J. Org. Chem. 2012, 77, 8386. ) that the boronic acid 22 was a highly effective catalyst that operated at room temperature.
Mark R. Biscoe at the City College of New York developed (J. Org. Chem. 2012, 77, 6629. ) a broadly functional group tolerant procedure to convert alkyl bromides such as 24 to the corresponding pinacol boranes. Meanwhile, the conversion of alkyl bromides to olefins (e.g. 26 to 27) via palladium-catalyzed dehydrohalogenation was developed (J. Am. Chem. Soc. 2012, 134, 14232. ) by Gregory C. Fu at Caltech.
A remarkably simple and chemoselective method for the direct conversion of aldehyde 28 to nitrile 30 using O-(diphenylphosphinyl)hydroxylamine 29 was developed (J. Org. Chem. 2012, 77, 9334. ) by Michael H. Nantz at the University of Louisville. Finally, zirconocene dichloride was found (Chem. Commun. 2012, 48, 11626. ) by Jonathan M. J. Williams at the University of Bath to be an effective transamidation catalyst, which operated even in the context of the acetal-containing substrate 31.