Alkylated Stereogenic Centers: The Romiti Synthesis of Eburnamenine

Zhongxian Li of the Henan Academy of Sciences and Fengqian Zhao and Junliang Wu of Zhengzhou University effected the decarboxylative coupling of the acid 1 with trimethylsilyl cyanide, leading to the nitrile 2 (Org. Lett. 2023, 25, 5006. DOI: 10.1021/acs.orglett.3c01637). Guozhu Zhang and Rui Guo of Central China Normal University used a Rh catalyst to rearrange the cyclobutanol 3 to the ketone 4 (Org. Lett. 2023, 25, 5151. DOI: 10.1021/acs.orglett.3c01870).

Fu-Min Zhang and Yong-Qiang Tu of Lanzhou University assembled the benzoate 7 by the Ni-catalyzed conjugate addition of the iodide 6 to the alkenyl pyrimidine 5 (J. Am. Chem. Soc. 2023, 145, 22122. DOI: 10.1021/jacs.3c07919). John F. Bower of the University of Liverpool added the ester 8 to the alkene 9, leading after decarboxylation to the benzothiazole 10 (J. Am. Chem. Soc. 2023, 145, 23918. DOI: 10.1021/jacs.3c10163). Christopher Uyeda of Purdue University prepared the alcohol 13 by opening the dihydrofuran 12 with the dichloride 11 (Angew. Chem. Int. Ed. 2023, 62, e202309681. DOI: 10.1002/anie.202309681). Yan-Kai Liu of the Ocean University of China used a Hayashi-Jørgensen amine to catalyze the conjugate addition of the masked aldehyde 14 to the bis sulfone 15, leading after oxidation to the imide 16 (Org. Lett. 2023, 25, 8220. DOI: 10.1021/acs.orglett.3c03182). Guoyin Yin of Wuhan University assembled the acetal 19 by coupling the alkyne 17 with the bromoester 18 (J. Am. Chem. Soc. 2023, 145, 18722. DOI: 10.1021/jacs.3c05969). De-Wei Gao of ShanghaiTech University prepared the gem bis-boronate 21 by the Ir-catalyzed coupling of a B-ate complex with the allylic carbonate 20 (Angew. Chem. Int. Ed. 2023, 62, e202307447. DOI: 10.1002/anie.202307447).

Yanli Zhao of Nanyang Technological University devised a porphyrin-containing covalentorganic framework complex that mediated the visible-light promoted coupling of the aldehyde 22 with the α-bromomalonate 23 to give 24 (J. Am. Chem. Soc. 2023, 145, 18015. DOI: 10.1021/jacs.3c05732). Jian-Qiang Zhao and Wei-Cheng Yuan of Chengdu University assembled the quaternary center of 27 by the Pd-mediated alkylation of the cyanoacetate 25 with the cyclic carbamate 26 (Org. Chem. Front. 2023, 10, 5971. DOI: 10.1039/D3QO01605F). James P. Morken of Boston College showed that the coupling of the ate complex derived from the boronate 28 with the allylic phosphonate 29 delivered 30 with retention of absolute configuration (J. Am. Chem. Soc. 2023, 145, 20755. DOI: 10.1021/jacs.3c07129). Jie Jiang and Yong-Qiang Zhang of Shandong University constructed the α-quaternary ester 33 by the Ti-mediated opening of the prochiral epoxide 31 with the allyl stannane 32 (J. Am. Chem. Soc. 2023, 145, 21122. DOI: 10.1021/jacs.3c08188).

The eburnamine alkaloids, including eburnamenine (37), were isolated from plants of the genus Kopsia of China and Southeast Asia. Filippo Romiti of the University of Texas at Dallas established a robust route to the lactone 36, having the central quaternary center of 37, based on the enantioselective coupling of the alkenyl zirconium 35 with the α-bromo lactone 34 (J. Am. Chem. Soc. 2023, 145, 20062. DOI: 10.1021/jacs.3c07019).