Conversion of 2-Iodobiaryls into 2,2'-Diiodobiaryls via Oxidation-Iodination Sequences: A Versatile Route to
1Division of Chemistry and Biological Chemistry, School of Physical and Mathematical Sciences, Nanyang Technological University, Singapore 637371 (Singapore).
Abstract:
Even though 2,2'-diiodo- and 2,2'-dibromobiaryls represent accomplished precursors for heterofluorenes and other extended π-conjugated systems, their preparation still remains nontrivial when structural diversity of the biaryl backbone is required. Herein, we report a convenient method for the preparation of various 2,2'-diiodobiaryls from 2-iodobiaryls via cyclic diaryliodonium intermediates. An iodinative ring-opening of the diaryliodonium salts, mediated by a copper/diamine catalyst system, is able to afford the corresponding 2,2'-diiodobiaryls under mild conditions. The versatility of this two-step approach is demonstrated by the preparation of hitherto unexplored tetraiodoteraryls and their conversion into ladder-type π-conjugated systems.
More Related Videos
10:14Synthesis and Purification of Iodoaziridines Involving Quantitative Selection of the Optimal Stationary Phase for Chromatography
Published on: May 16, 2014
12:27Synthesis of Hypervalent Iodonium Alkynyl Triflates for the Application of Generating Cyanocarbenes
Published on: September 8, 2013
Related Concept Videos
Electrophilic Aromatic Substitution: Fluorination and Iodination of Benzene
Alkynes to Aldehydes and Ketones: Hydroboration-Oxidation
One of the convenient methods for the preparation of aldehydes and ketones is via hydration of alkynes. Hydroboration-oxidation of alkynes is an indirect hydration reaction in which an alkyne is treated with borane followed by oxidation with alkaline peroxide to form an enol that rapidly converts into an aldehyde or a ketone. Terminal alkynes form aldehydes, whereas internal alkynes give ketones as the final product.
Hydroboration-Oxidation of Alkenes
Redox Titration: Iodimetry and Iodometry
Oxidation of Alkenes: Syn Dihydroxylation with Osmium Tetraoxide
Radical Substitution: Hydrogenolysis of Alkyl Halides with Tributyltin Hydride
The bonds formed in this reaction are stronger than the bonds broken, making it energetically favorable. The reaction follows a radical chain mechanism similar to radical halogenation reactions,...
