Organic Chemistry Portal
Organic Chemistry Highlights

Monday, May 29, 2023
Douglass F. Taber
University of Delaware

C-C Bond Construction: The Li/She Synthesis of Pharbilinic Acid

Burkhard König of University Regensburg observed significant diastereoselectivity in the conversion of the ketone 1 to the aldehyde 2 (Angew. Chem. Int. Ed. 2022, 61, e202211578. DOI: 10.1002/anie.202211578). John A. Murphy of the University of Strathclyde used a photocatalyst to activate the aryl alkyl ether 3 and add it in a conjugate sense to dimethyl fumarate 4, leading to the diester 5 (Chem. Sci. 2022, 13, 12921. DOI: 10.1039/D2SC04463C). Zhiliang Huang and Aiwen Lei of Wuhan University effected the oxidative cleavage of the tertiary alcohol 6 to the keto nitrile 7 (J. Am. Chem. Soc. 2022, 144, 13895. DOI: 10.1021/jacs.2c05520). Xuan Zhang of the Nanjing University of Science Information and Technology added the bromide 8 to acrylonitrile 9, trapping the intermediate with the chlorosilane 10 to give the α-silyl nitrile 11 (Nature Commun. 2022, 13, 7093. DOI: 10.1038/s41467-022-34901-6).

Kaori Ando of Gifu University effected the one-pot oxidation of the alcohol 12 and homologation of the intermediate aldehyde with the reagent 13, leading to the Z-unsaturated ester 14 (J. Org. Chem. 2022, 87, 9723. DOI: 10.1021/acs.joc.2c00763). Yifeng Chen of the East China University of Science and Technology carbonylated the allylic alcohol 15 to give the ketone 16 (Angew. Chem. Int. Ed. 2022, 61, e202210484. DOI: 10.1002/anie.202210484). Gojko Lalic of the University of Washington assembled the allylic alcohol 19 by coupling the alkyne 17 with the alkenyl bromide 18 (Angew. Chem. Int. Ed. 2022, 61, e202206462. DOI: 10.1002/anie.202206462). By adding the reagent 21 to the ketone 20, Keiji Tanino of Hokkaido University converted it into the prochiral 1,4-diene 22 (Org. Lett. 2022, 24, 5040. DOI: 10.1021/acs.orglett.2c01799).

Gerald B. Hammond of the University of Louisville and Bo Xu of Donghua University assembled the bromo alkyne 25 by the selective coupling of the alkynyl trifluoroborate 24 with the bromo triflate 23 (Org. Lett. 2022, 24, 6298. DOI: 10.1021/acs.orglett.2c02507). Ohyun Kwon of UCLA effected the oxidative coupling of the alkene 26 with the alkynyl sulfone 27, leading to the ester alkyne 28 (J. Am. Chem. Soc. 2022, 144, 14828. DOI: 10.1021/jacs.2c05980).

Chang Guo of the University of Science and Technology of China used the reagent 30 to convert the racemic propargylic alcohol 29 to the allene 31 in high ee (J. Am. Chem. Soc. 2022, 144, 21022. DOI: 10.1021/jacs.2c10863). Liang Yin of SIOC constructed the allene 34 in high ee by coupling the amide 32 with the imine 33 (ACS Catal. 2022, 12, 9181. DOI: 10.1021/acscatal.2c01399).

Pharbinilic acid (37), isolated from the morning glory Pharbitis nil, has been converted into derivatives having antiproliferative activity. In the course of the assembly of a known intermediate in the synthesis of 37, Huilin Li and Xuegong She of Lanzhou University used the Lebel protocol to prepare 36 by the selective methylenation of the diketone 35 (Org. Lett. 2022, 24, 6402. DOI: 10.1021/acs.orglett.2c02422).

D. F. Taber, Org. Chem. Highlights 2023, May 29.