C-H Functionalization: The Renata Synthesis of Manzacidin C

Timothy Noël of the Eindhoven University of Technology established flow conditions for the oxidation of the diester 1 to the ketone 2 (Angew. Chem. Int. Ed. 2018, 57, 4078. ). Vladimir Gevorgyan of the University of Illinois at Chicago oxidized the sulfonamide 3 to the alkene 4 (J. Am. Chem. Soc. 2018, 140, 2465. ). Yoshiharu Iwabuchi of Tohoku University showed that the hydroperoxide from the singlet oxygenation of 5 could readily be dehydrated to the enone 6 (Chem. Commun. 2018, 54, 798. ). David A. Nagib of Ohio State University devised conditions for the β-diodination of 7, leading, after hydrolysis and elimination, to the iodo alkene 8 (Chem. Sci. 2018, 9, 4500. ).

Zheng Huang of the Shangahi Institute of Organic Chemistry found that the transfer dehydrogenation of the alkane 9 with 10 and subsequent alkene migration and carbonylation could be carried out in a single pot, leading to the aldehyde 11 (J. Am. Chem. Soc. 2018, 140, 4157. ). Djamaladdin G. Musaev and Huw M. L. Davies of Emory University and Matthew S. Sigman of the University of Utah developed a Rh catalysis that mediated the regioselective, diastereoselective and enantioselective insertion of 13 into 12, leading to 14 (ACS Catal. 2018, 8, 678, ; Nature Chem. 2018, 10, 1048, ). Bing-Feng Shi of Zhejiang University coupled 15 with 16 to give 17 (Angew. Chem. Int. Ed. 2018, 57, 5858. ). In another example of photoredox catalysis, Kounosuke Oisaki and Motomu Kanai of the University of Tokyo inserted 19 into 18, leading to 20 (Chem. Commun. 2018, 54, 3215. ).

Sukbok Chang of KAIST observed high diastereoselectivity in the cyclization of 21 to 22 (Science 2018, 359, 1016. ). Mark J. Coster of Griffith University also achieved high diastereocontrol in the Rh-mediated cyclization of 23 to the spiroacetal 24 (Tetrahedron 2018, 74, 1313. ).

Professor Gevorgyan uncovered conditions for the atom transfer cyclization of 25 to 26 (Angew. Chem. Int. Ed. 2018, 57, 2712. ). Shinya Harusawa of the Osaka University of Pharmaceutical Sciences cyclized the cyanophosphate 27, by way of the intermediate alkylidene carbene, to the cyclopentene 28 (Tetrahedron 2018, 74, 2143. ).

Manzacidin C (31), isolated from the sponge Hymeniacidon sp., blocks the α-adrenoceptor. The preparative enzymatic hydroxylation of 29 to 30 was a key step in the synthesis of 31 developed by Hans Renata of Scripps/La Jolla (J. Am. Chem. Soc. 2018, 140, 1165. ).