Jump to main content
Jump to site search

Issue 37, 2018
Previous Article Next Article

Rhodium-catalyzed cyclization of acceptor-substituted biphenyl α-diazoketones: a study of the substitution effect on chemoselectivity

Author affiliations

Abstract

A range of biphenyl α-diazoketones containing various electron-withdrawing groups (EWG = COCH3, CN, CO2Et, COPh, SO2CH3, SO2Ph) on diazo carbon has been investigated for rhodium(II)-catalyzed intramolecular cyclization. Among which, the α-acetyl, carboxylate and cyano substituted substrates show markedly different selectivity between aromatic substitution and aromatic cycloaddition processes, affording phenanthrol and/or benz[α]azulenone products in varying ratios. The selectivity is mainly directed by α-substitutions, and is also possibly influenced by the substituents on the biphenyl ring. Moreover, high chemoselectivity for aromatic substitution over cycloaddition is observed for the α-benzoyl and sulfonyl substituted substrates. But in addition to phenanthrols, these reactions produce aromatic ketones and/or 1,2-diketones as unprecedented products obtained from diazo precursors. Mechanistic rationales are given in the report.

Graphical abstract: Rhodium-catalyzed cyclization of acceptor-substituted biphenyl α-diazoketones: a study of the substitution effect on chemoselectivity

Back to tab navigation

Supplementary files

Publication details

The article was received on 24 Jun 2018, accepted on 03 Sep 2018 and first published on 04 Sep 2018


Article type: Paper
DOI: 10.1039/C8OB01489B
Org. Biomol. Chem., 2018,16, 8353-8364

  •   Request permissions

    Rhodium-catalyzed cyclization of acceptor-substituted biphenyl α-diazoketones: a study of the substitution effect on chemoselectivity

    K. Chen, Y. Chiang and J. Zhu, Org. Biomol. Chem., 2018, 16, 8353
    DOI: 10.1039/C8OB01489B

Search articles by author

Spotlight

Advertisements