Organic Chemistry Portal
Organic Chemistry Highlights

Monday, October 14, 2013
Douglass F. Taber
University of Delaware

Substituted Benzenes: The Gu Synthesis of Rhazinal

Sisir K. Mandal of Asian Paints R&T Centre, Mumbai used (Tetrahedron Lett. 2013, 54, 530. DOI: 10.1016/j.tetlet.2012.11.075) 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. DOI: 10.1021/ja402083e) and John F. Hartwig of the University of California, Berkeley (J. Am. Chem. Soc. 2013, 135, 8480. DOI: 10.1021/ja4032677) 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. DOI: 10.1021/ja3100963) electrophilic borylation of the aniline 4 to give 5. The regioselectivity of Ir-catalyzed borylation (J. Am. Chem. Soc. 2013, 135, 7572, DOI: 10.1021/ja400295v; Org. Lett. 2013, 15, 140, DOI: 10.1021/ol303164h) is complementary to the electrophilic process. Professor Hartwig carried (Angew. Chem. Int. Ed. 2013, 52, 933. DOI: 10.1002/anie.201208203) 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. DOI: 10.1021/ol400507u) 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. DOI: 10.1021/ol400213f) 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. DOI: 10.1016/j.tetlet.2013.03.135) 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. DOI: 10.1002/adsc.201201018) 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. DOI: 10.1039/C2CC36951F) 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. DOI: 10.1002/adsc.201201007) 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. DOI: 10.1039/C3CC42080A) and Patrick J. Walsh of the University of Pennsylvania (Org. Lett. 2013, 15, 2298. DOI: 10.1021/ol4008876) 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. DOI: 10.1021/jo400594j) 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. DOI: 10.1021/ja404526x) 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. DOI: 10.1039/C3CC41107A) 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. DOI: 10.1021/ja400659s) 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. DOI: 10.1021/ja404494u) norbornene to direct the coupling and cyclization of 31 to give 32. Reduction followed by lactam formation completed the synthesis of Rhazinal (34).

D. F. Taber, Org. Chem. Highlights 2013, October 14.