C–H Functionalization

Abstract

Masayuki Inoue of the University of Tokyo oxidized (Tetrahedron Lett. 2011, 52, 4654) the alkyl benzene 1 to the nitrate 2, which could be carried on to the amide 5, the nitrile 6, the alcohol 7, or the azide 8. X. Peter Zhang of the University of South Florida developed (Chem. Sci. 2012, 2, 2361) a Co catalyst for the cyclization of 7 to 8. Justin Du Bois of Stanford University reported (J. Am. Chem. Soc. 2011, 133, 17207) the oxidative cyclization of the sulfamate corresponding to 7 using a Ru catalyst. Seongmin Lee of the University of Texas showed (Org. Lett. 2011, 13, 4766) that the oxidative cyclization of 9 gave the amine 10 with high diastereoselectivity. Fabrizio Fabris of the Università di Venezia used (Tetrahedron Lett. 2011, 52, 4478) a Ru catalyst to oxidize 11 to the ketone 12. Ying-Yeung Yeung of the National University of Singapore found (Org. Lett. 2011, 13, 4308) that hypervalent iodine was sufficient to oxidize 13 to the ketone 14. Huanfeng Jiang of the South China University of Technology methoxycarbonylated (Chem. Commun. 2011, 47, 12224) 15 under Pd catalysis to give 16. Professor Inoue found (Org. Lett. 2011, 13, 5928) that the oxidative cyanation of 17 proceeded with high diastereoselectivity to give 18. Mamoru Tobisu and Naoto Chatani of Osaka University activated (J. Am. Chem. Soc. 2011, 133, 12984) 19 with a Pd catalyst to enable coupling with 20 to give 21. Rh-mediated intramolecular insertion is well known to proceed efficiently into secondary and tertiary C–H bonds. A. Srikrishna of the Indian Institute of Science, Bangalore found (Synlett 2011, 2343) that insertion into the methyl C–H of 22 also worked smoothly to deliver 23. The macrocyclic oligopeptide valinomycin 24 has nine isopropyl groups. It is remarkable, as observed (Org. Lett. 2011, 13, 5096) by Cosimo Annese of the Università di Bari and Paul G. Williard of Brown University, that direct oxidation of 24 with methyl(trifluoromethyl) dioxirane in acetone specifically hydroxylated at 8 (45.5%, our numbering), 7 (28.5%), and 6 (26%).