C-H Functionalization: The Maulide Synthesis of Quinine

Wenjun Lu of Shanghai Jiao Tong University developed a general protocol for C-H bromination, converting 1 to 2 (Org. Lett. 2018, 20, 5264. DOI: 10.1021/acs.orglett.8b02208). Kensuke Kiyokawa and Satoshi Minakata of Osaka University oxidized 3 to the lactone 4 (Chem. Commun. 2018, 54, 7609. DOI: 10.1039/C8CC03735C). Alexey Sukhorukov of the N. D. Zelinsky Institute of Organic Chemistry acylated 5 with 6, leading to the pivalate 7 (J. Org. Chem. 2018, 83, 11057. DOI: 10.1021/acs.joc.8b01652). Dirk Trauner of New York University cyclized 8 to 9 (J. Am. Chem. Soc. 2018, 140, 8675. DOI: 10.1021/jacs.8b01918).

Armido Studer of the Westfälische Wilhelms-Universität converted 10 to the nitrile 11 (Angew. Chem. Int. Ed. 2018, 57, 12940. DOI: 10.1002/anie.201807455). Daniele Leonori of the University of Manchester reported related results (Angew. Chem. Int. Ed. 2018, 57, 12945. DOI: 10.1002/anie.201807941). Ning Jiao of Peking University combined 13 with 12 to give 14 (Nature Commun. 2018, 9, 2625. DOI: 10.1038/s41467-018-05014-w). Using 16, Erik J. Alexanian of the University of North Carolina effected the allylation of 15, leading to 17 (Angew. Chem. Int. Ed. 2018, 57, 13106. DOI: 10.1002/anie.201806963). Vincent Gandon and Samir Messaoudi of the Université Paris-Sud applied remote arylation conditions to the carbohydrate derivative 18, coupling it with 19 to give 20 (ACS Catal. 2018, 8, 7781. DOI: 10.1021/acscatal.8b01617). Jin-Quan Yu of Scripps-La Jolla showed that the versatile Weinreb amide could be used to direct arylation, coupling 21 with 19 to give 22 (ACS Catal. 2018, 8, 9292. DOI: 10.1021/acscatal.8b03014). David Y. K. Chen of Seoul National University assembled 25 by coupling 23 with 24 (J. Org. Chem. 2018, 83, 6936. DOI: 10.1021/acs.joc.7b02426).

Kilian Muñiz of ICIQ found that 26 could be cyclized to the pyrrolidine 27 by oxidation in the presence of a bromine source (Angew. Chem. Int. Ed. 2018, 57, 5166. DOI: 10.1002/anie.201800375). Aiwen Lei of Wuhan University reported the same cyclization using electrochemical oxidation (ACS Catal. 2018, 8, 9370. DOI: 10.1021/acscatal.8b02847).Chi-Ming Che of the University of Hong Kong used an iron catalyst to cyclize 28 to 29 (Angew. Chem. Int. Ed. 2018, 57, 11947. DOI: 10.1002/anie.201806059).

The total synthesis of quinine (33) has fascinated organic chemists for almost 200 years. Nuno Maulide of the University of Vienna reported an elegant entry, using directed palladation to couple the readily available 30 with 31, leading to 32 (Angew. Chem. Int. Ed. 2018, 57, 10737. DOI: 10.1002/anie.201804551).