Synthesis of Selenoesters via Aldol Condensation and/or Conjugate Reduction and Their Antiviral Activities

Alex Boateng; Masayuki Amano; Masaharu Sugiura

doi:10.1021/acsomega.2c06784

Synthesis of Selenoesters via Aldol Condensation and/or Conjugate Reduction and Their Antiviral Activities

ACS Omega. 2022 Dec 27;8(1):1369-1374. doi: 10.1021/acsomega.2c06784. eCollection 2023 Jan 10.

Authors

Alex Boateng¹, Masayuki Amano^{2

3}, Masaharu Sugiura¹

Affiliations

¹ Graduate School of Pharmaceutical Sciences, Sojo University, 4-22-1 Ikeda, Nishi-ku, Kumamoto 860-0082, Japan.
² Department of Hematology, Rheumatology and Infectious Diseases, School of Medicine, Kumamoto University, Kumamoto 860-8556, Japan.
³ Department of Clinical Retrovirology, Joint research Center for Human Retrovirus Infection, Kumamoto University, Kumamoto 860-0811, Japan.

Abstract

A variety of unsaturated selenoesters (including phenolic ones) were produced in good to high yields and with high E/Z ratios using TiCl₄-promoted aldol condensation between Se-phenyl selenoacetate and their respective aldehydes without aqueous workup. A representative phenolic unsaturated selenoester was applied to acylation of tyrosine methyl ester without protection of the phenolic hydroxy groups to furnish the corresponding amino acid conjugate. The conjugate reduction of the unsaturated selenoesters including phenolic ones and selenocoumarin with HSiEt₃ was catalyzed by B(C₆F₅)₃ to afford the corresponding saturated selenoesters in good to high yields. This method was also applicable to the reduction of a saturated selenoester to the corresponding O-silyl hemiselenoacetal in a high yield. Moreover, most acyclic unsaturated selenoesters were found to show good multiple antiviral activities against HIV-1, HBV, and SARS-CoV-2.