Heteroaromatics: The Shao/Zhao Synthesis of Cermizine B

Shao-Hua Wang of Lanzhou University rearranged the diol 1 to the furan 2 (Org. Biomol. Chem. 2017, 15, 6333. DOI: 10.1039/C7OB01179B). Rongshun Chen of Nanjing Agricultural University and Zhengjie He of Nankai University added 4 to 3 to give the furan 5 (Tetrahedron Lett. 2017, 58, 3722. DOI: 10.1016/j.tetlet.2017.08.027).

Y. Jayaprakash Rao of Osmania University and B. V. Subba Reddy of the Indian Institute of Chemical Technology prepared the pyrrole 8 by combining 6 with 7 (Org. Biomol. Chem. 2017, 15, 7580. DOI: 10.1039/C7OB00705A). Kirsten Zeitler of the Universität Leipzig devised the multicomponent coupling of 9 with, sequentially, 10, 11, and 12, leading to the pyrrole 13 (J. Org. Chem. 2017, 82, 7796. DOI: 10.1021/acs.joc.7b00830).

Bernhard Breit of the Albert-Ludwigs-Universität Freiburg assembled the pyridine 16 by the Rh-catalyzed addition of 14 to the allene derived from 15 (Angew. Chem. Int. Ed. 2017, 56, 8422. DOI: 10.1002/anie.201704022). Wang-Ze Song of the Dalian University of Technology developed the Rh-catalyzed cyclization of 17 to the pyridine 18 (Heterocycles 2017, 94, 1289. DOI: 10.3987/COM-17-13686). Sampak Samanta of the Indian Institute of Technology Indore added 19 in a conjugate sense to 20, leading after rearrangement to the pyridine 21 (J. Org. Chem. 2017, 82, 10928. DOI: 10.1021/acs.joc.7b01792). Rengarajan Balamurugan of the University of Hyderabad combined 22 with 23 to give the pyridine 24 (Eur. J. Org. Chem. 2017, 3941. DOI: 10.1002/ejoc.201700559).

Ping Hu and Yun He of Chongqing University effected the oxidative cyclization of 25 to the indole 26 (Chem. Commun. 2017, 53, 11205. DOI: 10.1039/C7CC06448A). Xi-Sheng Wang of the University of Science and Technology of China developed the complementary oxidative cyclization of 27 to the indole 28 (Angew. Chem. Int. Ed. 2017, 56, 15436. DOI: 10.1002/anie.201709894). Prasanta Ghorai of the Indian Institute of Science Education and Research Bhopal cyclized the diketone 29 with benzylamine to give the indole 30 (J. Org. Chem. 2017, 82, 8426. DOI: 10.1021/acs.joc.7b01136). Alessandro Palmieri of the University of Camerino added the nitro ketal 32 to the aldehyde 31 to give an intermediate that could be cyclized with acid to the indole 33 (Adv. Synth. Catal. 2017, 359, 3407. DOI: 10.1002/adsc.201700790). Christopher G. Frost of the University of Bath reviewed a range of methods for functionalizing the preformed indole nucleus (ACS Catal. 2017, 7, 5618. DOI: 10.1021/acscatal.7b01785).

In the course of a synthesis of cermizine B (37), Li-Dong Shao and Qin-Shi Zhao of the Kunming Institute of Botany added 35 in a conjugate sense to 34 to give the expected the diastereomer 36, the product of axial addition (J. Org. Chem. 2017, 82, 11110. DOI: 10.1021/acs.joc.7b02073). It is striking that CuCN-mediated addition gave predominantly the alternative diastereomer (not illustrated).