The possibility of direct introduction of a new functionality (or a new C–C bond) via direct C–H bond transformation is a highly attractive strategy in covalent synthesis. The range of substrates is virtually unlimited, including hydrocarbons, complex organic compounds of small molecular weight, and synthetic and biological polymers. Below is a list of recent articles on this topic. For a review, see
Breaking the mirror (plane): A palladium-catalyzed desymmetrization strategy via β C−H activation provides an alternate approach for solving the age-old challenge of introducing an α-methyl stereocenter to a molecule.
David A. Nagib
Angew. Chem. Int. Ed., April 28, 2017, https://doi.org/10.1002/anie.201703311 Read article
New direction: An amide-directed ortho and lateral C−H sodiation is enabled by sodium hydride (NaH) in the presence of either sodium iodide (NaI) or lithium iodide (LiI). The transient organosodium intermediates could be transformed into functionalized aromatic compounds.
Yinhua Huang, Guo Hao Chan, Shunsuke Chiba
Angew. Chem. Int. Ed., April 27, 2017, https://doi.org/10.1002/anie.201702512 Read article
An efficient protocol for the direct C6–H arylation of purines and purine nucleosides is described under the catalysis of silver nitrate and under ambient conditions. A wide assortment of purines and arylboronic acids can be employed in this process to afford C6-arylpurines and purine nucleosides with high regioselectivity. TFA = trifluoroacetic acid; DCE = 1,2-dichloroethane.
Miao Tian, Mingwu Yu, Tingting Shi, Junbin Hu, Shunlai Li, Jiaxi Xu, Ning Chen, Hongguang Du
Eur. J. Org. Chem., April 26, 2017, https://doi.org/10.1002/ejoc.201700406 Read article
Developing efficient and selective routes for biaryl synthesis is of great interest. Decarboxylative oxidative coupling is appealing, because both substrate classes are readily available, and only CO2 and H2O are formed as side products. Furthermore, the carboxyl group offers a site for selective transformations. This review details decarboxylative oxidative coupling from 2008 to the present.
Gregory J. P. Perry, Igor Larrosa
Eur. J. Org. Chem., April 26, 2017, https://doi.org/10.1002/ejoc.201700121 Read article
Benzylic C−H oxidation in HFIP: The aerobic oxidation of methylarenes to benzaldehydes using N-hydroxyphthalimide (NHPI) and cobalt(II) acetate in 1,1,1,3,3,3-hexafluoropropan-2-ol (HFIP) is highly selective. The mild sustainable conditions are compatible with different chemical functionalities, including alcohols and alkenes, and are suitable for oxidizing both electron-deficient and electron-efficient methylarenes.
Eden Gaster, Sebastian Kozuch, Doron Pappo
Angew. Chem. Int. Ed., April 24, 2017, https://doi.org/10.1002/anie.201702511 Read article
A convenient and efficient copper-promoted thiolation of (hetero)arene and alkene C–H bonds with disulfides was achieved with a broad substrate scope by using a new and removable 2-amino alkylbenzimidazole (MBIP amine) directing group.
Shuang-Liang Liu, Xue-Hong Li, Tan-Hao Shi, Guang-Chao Yang, Hai-Li Wang, Jun-Fang Gong, Mao-Ping Song
Eur. J. Org. Chem., April 21, 2017, https://doi.org/10.1002/ejoc.201700147 Read article
Prepare to dye: A variety of D–π–A-type functional organic dyes are facilely synthesized by direct C−H arylation catalyzed by inexpensive copper salts with broad substrate scope and good functional group compatibility. Three new dye sensitizers are fabricated for use in dye-sensitized solar cells (DSSCs), representing the first use of Cu-catalyzed C−H arylation for a step-saving, Sn-free synthesis of precursor dyes for DSSC applications.
Jiung-Huai Huang, Po-Han Lin, Wei-Ming Li, Kun-Mu Lee, Ching-Yuan Liu
ChemSusChem, April 21, 2017, https://doi.org/10.1002/cssc.201700421 Read article
Born metal-free: A metal-free synthesis of pyrimidines through a [3+2+1]-type intermolecular cycloaddition reaction with C(sp3)−H activation features sustainable oxidants, readily available substrates, and high atom and step economies.
Lv-Yin Zheng, Wei Guo, Xiao-Lin Fan
Asian J. Org. Chem., April 21, 2017, https://doi.org/10.1002/ajoc.201700105 Read article
C–H activation in saturated ethers followed by functionalization with various coupling partners under oxidative conditions has been an area of significant interest. This microreview sheds light on C–C and C–heteroatom bond formation in these inactivated ethers.
Aanchal Batra, Paramjit Singh, Kamal Nain Singh
Eur. J. Org. Chem., April 20, 2017, https://doi.org/10.1002/ejoc.201700341 Read article
Pitambar Patel, Gongutri Borah
Eur. J. Org. Chem., April 20, 2017, https://doi.org/10.1002/ejoc.201700095 Read article
An arrow to the Ni: A solvent-free method for the C−H arylation of arenes and indoles has been developed, which proceeds by nickel catalysis through monodentate chelation assistance. The cost-effective nickel catalyst promotes selective mono-arylation and the reaction tolerates a wide range of functional groups.
Rahul A. Jagtap, Vineeta Soni, Benudhar Punji
ChemSusChem, April 18, 2017, https://doi.org/10.1002/cssc.201700321 Read article
A facile synthesis of diversified indoles through a deprotection of bis-heterocycles resulting from an oxidative annulation of benzothiazole-substituted anilines with alkynes is reported. A key feature of this strategy is the use of benzothiazole as a removable directing group that is reported for the first time.
Shivani Sharma, Sukanya Singh, Akhilesh Kumari, Devesh M. Sawant, Ram T. Pardasani
Asian J. Org. Chem., March 29, 2017, https://doi.org/10.1002/ajoc.201700098 Read article
Gimme the light! Benzylic C−H bonds of toluene derivatives are directly arylated with aryl halides by means of a nickel–dtbbpy catalyst under irradiation with UV light; dtbbpy=4,4′-di-tert-butyl-2,2′-bipyridine.
Naoki Ishida, Yusuke Masuda, Norikazu Ishikawa, Masahiro Murakami
Asian J. Org. Chem., March 21, 2017, https://doi.org/10.1002/ajoc.201700115 Read article
Two is better than one to generate cyclometalated Cp*IrIII phosphoramidate complexes by sequential intramolecular B–H and C(sp3)–H bond-activation events. Such complexes represent a first step in an overall Ir-catalyzed process for organophosphate functionalization. Cp* = pentamethylcyclopentadienyl; Mes = mesityl.
Marcus W. Drover, Cheyenne J. Christopherson, Laurel L. Schafer, Jennifer A. Love
Eur. J. Inorg. Chem., February 13, 2017, https://doi.org/10.1002/ejic.201601518 Read article
Only a little bit of iodine: A synthetic strategy for an iodine-mediated sulfonylation of quinoline N-oxides has been developed. A wide variety of 2-sulfonyl quinoline derivatives were synthesized by reacting various quinoline N-oxides with different sodium sulfinates in the presence of sub-stoichiometric amounts of I2 in one pot, after 2 h at room temperature.
Wen-Kai Fu, Kai Sun, Chen Qu, Xiao-Lan Chen, Ling-Bo Qu, Wen-Zhu Bi, Yu-Fen Zhao
Asian J. Org. Chem., February 08, 2017, https://doi.org/10.1002/ajoc.201700001 Read article