Metal-Mediated C-C Ring Construction: The Ota/Miyaoka Synthesis of Saniculamoid D

Dennis G. Hall of the University of Alberta effected the enantioselective coupling of the prochiral dibromide 1 with the trifluoroborate 2, leading to the cyclobutene 3 in high ee (Angew. Chem. Int. Ed. 2023, 62, e202313503. DOI: 10.1002/anie.202313503). Kazuaki Ishihara of Nagoya University used an iron catalyst to promote the photochemical coupling of the cinnamaldehyde 4 with the styrene 5 to give the cyclobutane 6 (J. Am. Chem. Soc. 2023, 145, 15054. DOI: 10.1021/jacs.3c04010).

Shi-Kun Jia, Guang-Jian Mei and Yuan-Zhao Hua of Zhengzhou University assembled the cyclopentandione 9 by coupling the cyclopentendione 7 with the α-hydroxy ketone 8 (Chem. Asian J. 2023, 18, e202300591. DOI: 10.1002/asia.202300591). Bo Chen and Xiangyou Xing of the Southern University of Science and Technology achieved high ee in the ring-opening cross metathesis of allyl benzoate with the Diels-Alder adduct 10 to give the cyclopentane 11 (J. Am. Chem. Soc. 2023, 145, 22745. DOI: 10.1021/jacs.3c08420). Shaolin Zhu of Nanjing University prepared the cyclopentane 14 by the migratory hydrofunctionalization of the cyclopentene 12 with the iodide 13 (Angew. Chem. Int. Ed. 2023, 62, e202308320. DOI: 10.1002/anie.202308320). Masahisa Nakada of Waseda University achieved high enantioselectivity and diastereoselectivity in the construction of the cyclopentanone 17 by the addition of the enol silane 16 to the sulfone 15 (Synlett 2023, 34, 1235. DOI: 10.1055/a-2030-7082).

Zhulin Tan and Jinhua J. Song of Boeringer Ingelheim established conditions for opening the epoxide 18 with an alkyl Grignard reagent, leading to 19 (Org. Process Res. Dev. 2024, 28, 78. DOI: 10.1021/acs.oprd.3c00363), optimizing the epoxidation with the Shi catalyst. Xiaoming Feng and Xiaohua Liu of Sichuan University reported the enantioselective preparation of 18 using a Co catalyst (J. Am. Chem. Soc. 2023, 145, 15611. DOI: 10.1021/jacs.3c05476). John A. Gladysz of Texas A&M assembled the cyclohexanone 22 by combining the Nazarov reagent 20 with the nitroalkene 21 (Adv. Synth. Catal. 2023, 365, 4692. DOI: 10.1002/adsc.202300972). Rendy Kartika of Louisiana State University devised the enantioselective 1,2-addition of a Grignard reagent to the enone 23, leading, after Claisen rearrangement, to the cyclohexanone 24 (Org. Lett. 2023, 25, 7622. DOI: 10.1021/acs.orglett.3c02752). Liming Zhang of the University of California, Santa Barbara devised the dearomatizing cyclization of the phenol 25 to the lactam 26 (Angew. Chem. Int. Ed. 2023, 62, e202309256. DOI: 10.1002/anie.202309256).

Durga Prasad Hari of the Indian Institute of Science, Bangalore, established the one-carbon ring expansion of the cyclohexanone 27 to the cycloheptanone 28 (Chem. Sci. 2023, 14, 6930. DOI: 10.1039/D3SC01908J). Eric Meggers of Phillips-Universität Marburg designed a chiral at Ru catalyst that cyclized the diazo ketone 29 to the bicyclic ketone 30 in high ee (Synlett 2023, 34, 1403. DOI: 10.1055/s-0042-1751372).

Saniculamoid D (33) was isolated from the dried whole plant powder of Sanicula lamelligera, used extensively in East Asian medicine. Koichiro Ota and Hiroaki Miyaoka of the Tokyo University of Pharmacy and Life Sciences assembled 33 by the Hodgson cyclization of 31 to 32 (Synlett 2023, 34, 2304. DOI: 10.1055/a-2147-9454).