Substituted Benzenes: The Gu Synthesis of Rhazinal
Sisir K. Mandal of Asian Paints R&T Centre, Mumbai used (Tetrahedron Lett. 2013, 54, 530. ) a Ru catalyst to couple 2 with an electron-rich arene 1 to give 3. Jun-ichi Yoshida of Kyoto University (J. Am. Chem. Soc. 2013, 135, 5000. ) and John F. Hartwig of the University of California, Berkeley (J. Am. Chem. Soc. 2013, 135, 8480. ) also reported direct amination protocols. Tommaso Marcelli of the Politecnico di Milano and Michael J. Ingleson of the University of Manchester effected (J. Am. Chem. Soc. 2013, 135, 474. ) electrophilic borylation of the aniline 4 to give 5. The regioselectivity of Ir-catalyzed borylation (J. Am. Chem. Soc. 2013, 135, 7572, ; Org. Lett. 2013, 15, 140, ) is complementary to the electrophilic process. Professor Hartwig carried (Angew. Chem. Int. Ed. 2013, 52, 933. ) the borylated product from 6 on to Ni-mediated coupling to give the alkylated product 7.
Weiping Su of the Fujian Institute of Research on the Structure of Matter devised (Org. Lett. 2013, 15, 1718. ) an intriguing Pd-mediated oxidative coupling of nitroethane 9 with 8 to give 10. The coupling is apparently not proceeding via nitroethylene.
Peiming Gu of Ningxia University developed (Org. Lett. 2013, 15, 1124. ) an azide based cleavage that converted the aldehyde 11 into the formamide 13. Zhong-Quan Liu of Lanzhou University showed (Tetrahedron Lett. 2013, 54, 3079. ) that an aromatic carboxylic acid 14 could be oxidatively decarboxylated to the chloride 15. Gérard Cahiez of the Université Paris 13 found (Adv. Synth. Catal. 2013, 355, 790. ) mild Cu-catalyzed conditions for the reductive decarboxylation of aromatic carboxylic acids, and Debabrata Maiti of the Indian Institute of Technology, Mumbai found (Chem. Commun. 2013, 49, 252. ) Pd-mediated conditions for the dehydroxymethylation of benzyl alcohols (neither illustrated). Pravin R. Likhar of the Indian Institute of Chemical Technology prepared (Adv. Synth. Catal. 2013, 355, 751. ) a Cu catalyst that effected Castro-Stephens coupling of 16 with 17 at room temperature. Arturo Orellana of York University (Chem. Commun. 2013, 49, 5420. ) and Patrick J. Walsh of the University of Pennsylvania (Org. Lett. 2013, 15, 2298. ) showed that a cyclopropanol 20 can couple with an aryl halide 19 to give 21.
Yunkui Liu of Zhejiang University of Technology effected (J. Org. Chem. 2013, 78, 5932. ) specific ortho nitration of the methoxime 22 to give 23. Jin-Quan Yu of Scripps/La Jolla devised (J. Am. Chem. Soc. 2013, 135, 9322. ) conditions for specific ortho phosphorylation of 25 to give 26.
Sunggak Kim of Nanyang Technological University and Phil Ho Lee of Kangwon National University found (Chem. Commun. 2013, 49, 4682. ) that the monophosphoric acid group of 27 could direct ortho coupling with ethyl acrylate to give 28. Professor Yu found (J. Am. Chem. Soc. 2013, 135, 7567. ) that the ether of 29 was also effective for directing ortho coupling with ethyl acrylate, to give 30.
Zhenhua Gu of the University of Science and Technology of China, following a protocol developed by Catellani, used (J. Am. Chem. Soc. 2013, 135, 9318. ) norbornene to direct the coupling and cyclization of 31 to give 32. Reduction followed by lactam formation completed the synthesis of Rhazinal (34).