Functional Group Transformations
Mark Gandelman of the Technion - Israel Institute of Technology devised (Adv. Synth. Catal. 2011, 353, 1438. ) a protocol for the decarboxylative conversion of an acid 1 to the iodide 3. Doug E. Frantz of the University of Texas, San Antonio effected (Angew. Chem. Int. Ed. 2011, 50, 6128. ) conversion of a β-keto ester 4 to the diene 5, by way of the vinyl triflate.
Pei Nian Liu of the East China University of Science and Technology and Chak Po Lau of the Hong Kong Polytechnic University (Adv. Synth. Catal. 2011, 353, 275. ) and Robert G. Bergman and Kenneth N. Raymond of the University of California, Berkeley (J. Am. Chem. Soc. 2011, 133, 11964. ) described new Ru catalysts for the isomerization of an allylic alcohol 6 to the ketone 7. Xiaodong Shi of West Virginia University optimized (Adv. Synth. Catal. 2011, 353, 2584. ) a gold catalyst for the rearrangement of a propargylic ester 8 to the enone 9.
Xue-Yuan Liu of Lanzhou University used (Adv. Synth. Catal. 2011, 353, 3157. ) a Cu catalyst to add the chloramine 11 to the alkyne 10, to give 12. Kasi Pitchumani of Madurai Kamaraj University converted (Org. Lett. 2011, 13, 5728. ) the alkyne 13 into the α-amino amide 15 by reaction with the nitrone 14.
Katsuhiko Tomooka of Kyushu University effected (J. Am. Chem. Soc. 2011, 133, 20712. ) hydrosilylation of the propargylic ether 16 to the alcohol 17. Matthew J. Cook of Queen's University Belfast (Chem. Commun. 2011, 47, 11104. ) and Anna M. Costa and Jaume Vilarrasa of the Universitat de Barcelona (Org. Lett. 2011, 13, 4934. ) improved the conversion of an alkenyl silane 18 to the iodide 19.
Vinay Girijavallabhan of Merck/Kenilworth developed (J. Org. Chem. 2011, 76, 6442. ) a Co catalyst for the Markovnikov addition of sulfide to an alkene 20. Hojat Veisi of Payame Noor University oxidized (Synlett 2011, 2315. ) the thiol 22 directly to the sulfonyl chloride 23. Nicholas M. Leonard of Abbott Laboratories prepared (J. Org. Chem. 2011, 76, 9169. ) the chromatography-stable O-Su ester 25 from the corresponding acid 24. Diego J. Ramón of the Universidad de Alicante coupled (J. Org. Chem. 2011, 76, 5547. ) the alcohol 26 with a sulfonamide to give the protected amine 27.
While short (up to about 40) oligopeptides are readily prepared by bead-based synthesis, longer oligopeptides and proteins are prepared by convergent coupling of the oligopeptides so prepared using thioester-based native chemical ligation. Some C-terminal amino acids, however, including proline, do not work well. Thomas Durek of the University of Queensland showed (Angew. Chem. Int. Ed. 2011, 50, 12042. ) that the selenyl ester 29 participated more efficiently.