Academic literature on the topic 'C-H Amination'

Christian R. Goldsmith of Auburn University developed (Synlett 2010, 1377) a method for radical chlorination of 1 using commercial peracetic acid. Noritaka Mizuno of the University of Tokyo devised (Nat. Chem. 2010, 2, 478) a bulky polyoxometalate that mediated the selective hydroxylation of the secondary C-H bonds of 3. Christina White of the University of Illinois showed (Science 2010, 327, 566) that Fe-mediated C-H oxidation is sensitive to the expected electronic effects, so that 5 was selectively oxidized to 6. Irena S. Akhrem of the A. N. Nesmeyanov Institute of Organoelement Compounds established (Tetrahedron Lett. 2010, 51, 259) that a C-H bond of 7 could be efficiently converted to a C-C bond. Melanie S. Sanford of the University of Michigan extended (Organic Lett. 2010, 12, 532) directed palladation to 9, effecting selective acetoxylation of the methyl group. Herman O. Sintim of the University of Maryland observed (Angew. Chem. Int. Ed. 2010, 49, 3964) that the O-linked diazoamide 11 selectively cyclized to 12. The corresponding C-linked diazoamide gave only five-membered ring formation. Yasushi Obora and Yasutaka Ishii of Kansai University devised (Organic Lett. 2010, 12, 1372) conditions for the selective allylic amination of 13. Marvin J. Miller of the University of Notre Dame developed (Tetrahedron Lett. 2010, 51, 328) the nitrosoisoxazole 16 for the allylic amination of 15. David A. Powell of Merck Frosst established (J. Org. Chem. 2010, 75, 2726) a protocol for the selective amination of the aromatic methyl group of 18. Ying-Yeung Yeung of the National University of Singapore effected (Organic Lett. 2010, 12, 2128) selective allylic oxidation of 21 with a hypervalent iodine reagent. Gullapalli Kumaraswamy of the Indian Institute of Chemical Technology, Hyderabad, allylated (J. Org. Chem. 2010, 75, 3916) an amine 23 using commercial aqueous t -BuOOH. Corey R. J. Stephenson of Boston University used (J. Am. Chem. Soc. 2010, 132, 1464) visible light to activate 26 for homologation to 27. In the course of a synthesis of the bicyclic nonribosomal peptide celogentin C, isolated from the seeds of the plumed cockscomb Celosia argentea, Gong Chen of Pennsylvania State University took advantage (Angew. Chem. Int. Ed. 2010, 49, 958) of Pd activation to effect specific coupling of the iodoindole 29 with the leucine derivative 28. On a 4-gram scale, this coupling proceeded in 85% yield.

Konstantin P. Bryliakov of the Boreskov Institute of Catalysis devised (Org. Lett. 2012, 14, 4310) a manganese catalyst for the selective tertiary hydroxylation of 1 to give 2. Note that the electron-withdrawing Br deactivates the alternative methine H. Bhisma K. Patel of the Indian Institute of Technology, Guwahati selectively oxidized (Org. Lett. 2012, 14, 3982) a benzylic C–H of 3 to give the corresponding benzoate 4. Dalibor Sames of Columbia University cyclized (J. Org. Chem. 2012, 77, 6689) 5 to 6 by intramolecular hydride abstraction followed by recombination. Thomas Lectka of Johns Hopkins University showed (Angew. Chem. Int. Ed. 2012, 51, 10580) that direct C–H fluorination of 7 occurred predominantly at carbons 3 and 5. John T. Groves of Princeton University reported (Science 2012, 337, 1322) an alternative manganese porphyrin catalyst (not illustrated) for direct fluorination. C–H functionalization can also be mediated by a proximal functional group. John F. Hartwig of the University of California, Berkeley effected (J. Am. Chem. Soc. 2012, 134, 12422) Ir-mediated borylation of an ether 9 in the position β to the oxygen to give 10. Uttam K. Tambar of the UT Southwestern Medical Center devised (J. Am. Chem. Soc. 2012, 134, 18495) a protocol for the net enantioselective amination of 11 to give 12. Conversion of a C–H bond to a C–C bond can be carried out in an intramolecular or an intermolecular sense. Kilian Muñiz of the Catalan Institution for Research and Advanced Studies cyclized (J. Am. Chem. Soc. 2012, 134, 15505) the terminal alkene 13 directly to the cyclopentene 15. Olivier Baudoin of Université Claude Bernard Lyon 1 closed (Angew. Chem. Int. Ed. 2012, 51, 10399) the pyrrolidine ring of 17 by selective activation of a methyl C–H of 16. Jeremy A. May of the University of Houston found (J. Am. Chem. Soc. 2012, 134, 17877) that the Rh carbene derived from 18 inserted into the distal alkyne to give a new Rh carbene 19, which in turn inserted into a C–H bond adjacent to the ether oxygen to give 20.

A classic example of C-H functionalization is the familiar NBS bromination of a benzylic site. Recent updates of this approach allow for direct alkoxylation (J. Am. Chem. Soc. 2008, 130, 7824) and net amination (Organic Lett. 2008, 10, 1863). For the amination of simple aliphatic H’s, Holger F. Bettinger of Ruhr-Universität Bochum developed (Angew. Chem. Int. Ed. 2008, 47, 4744) the boryl azide 2. The insertion with 1 proceeded to give a statistical mixture of the nitrene insertion products 3 and 4. The tethered C-H functionalization devised (J. Am. Chem. Soc. 2008, 130, 7247) by Phil S. Baran of Scripps-La Jolla is selective, as in the conversion to 5 to 6, but appears to be limited to tertiary and benzylic C-H sites. Michael P. Doyle of the University of Maryland established (J. Org. Chem. 2008, 73, 4317) an elegant protocol for the oxidation of an alkyne such as 7 to the ynone 8. Note that the oxidation did not move the alkyne. Marta Catellani of the Università di Parma reported (Adv. Synth. Cat. 2008, 350, 565) the intriguing Pd-catalyzed conversion of 9 to 10. Under mild conditions, it might likely be possible to hydrolyze the vinyl ether to reveal the phenol 11. Another way of looking at this overall transformation would be to consider the ether 10 to be a protected form of the aldehyde 12. C-H activation can also lead to C-C bond formation. Irena S. Akhrem of the Nesmeyanov Institute, Moscow, described (Tetrahedron Lett. 2008, 49, 1399) a hydride-abstraction protocol for three-component coupling of a hydrocarbon 13 , an amine 14 , and CO, leading to the homologated amide 15. Hua Fu of Tsinghua University, Beijing, showed (J. Org. Chem. 2008 , 73, 3961) that oxidation of an amine 16 led to an intermediate that could be coupled with an alkyne 17 to give the propargylic amine 18. Products 15 and 18 are the result of sp2 and sp coupling, respectively. C-H functionalization leading to sp3 -sp3 coupling is less common. Jin-Quan Yu of Scripps/La Jolla found (J. Am. Chem. Soc. 2008, 130, 7190) that activation of the N-methoxy amide 19 in the presence of the alkyl boronic acid 20 gave smooth coupling, to 21.

Matthias Beller of the Universität Rostock developed (Angew. Chem. Int. Ed. 2014, 53, 6477) a Rh catalyst for the acceptorless dehydrogenation of an alkane 1 to the alkene 2. Bhisma K. Patel of the Indian Institute of Technology Guwahati effected (Org. Lett. 2014, 16, 3086) oxidation of cyclohexane 3 and 4 to form the allylic benzoate 5. Justin Du Bois of Stanford University devised (Chem. Sci. 2014, 5, 656) an organocatalyst that mediated the hydroxylation of 6 to 7. Vladimir Gevorgyan of the University of Illinois, Chicago hydrosilylated (Nature Chem. 2014, 6, 122) 8 to give an intermediate that, after Ir-catalyzed intramolecular C–H functionalization followed by oxidation, was converted to the diacetate 9. Sukbok Chang of KAIST used (J. Am. Chem. Soc. 2014, 136, 4141) the methoxime of 10 to direct selective amination of the adjacent methyl group, leading to 11. John F. Hartwig of the University of California, Berkeley effected (J. Am. Chem. Soc. 2014, 136, 2555) diastereoselective Cu-catalyzed amination of 12 with 13 to make 14. David W. C. MacMillan of Princeton University accomplished (J. Am. Chem. Soc. 2014, 136, 6858) β-alkylation of the aldehyde 15 with acrylonitrile 16 to give 17. Yunyang Wei of the Nanjing University of Science and Technology alkenylated (Chem. Sci. 2014, 5, 2379) cyclohexane 3 with the styrene 18, leading to 19. Bin Wu of the Kunming Institute of Botany described (Org. Lett. 2014, 16, 480) the Pd-mediated cyclization of 20 to 21. Similar results using Cu catalysis were reported (Angew. Chem. Int. Ed. 2014, 53, 3496, 3706) by Yoichiro Kuninobu and Motomu Kanai of the University of Tokyo and by Haibo Ge of IUPUI. Jin-Quan Yu of Scripps La Jolla constructed (J. Am. Chem. Soc. 2014, 136, 5267) the lactam 24 by γ-alkenyl­ation of the amide 22 with 23, followed by cyclization. Philippe Dauban of CNRS Gif-sur-Yvette prepared (Eur. J. Org. Chem. 2014, 66) the useful crystalline chiron 27 by asymmetric amination of the enol triflate 26 with 25. Matthew J. Gaunt of the University of Cambridge showed (J. Am. Chem. Soc. 2014, 136, 8851) that the phenylative cyclization of 28 with 29 to 30 proceeded with near-perfect retention of absolute configuration.