Access to the γ-amino-β,γ-unsaturated acyl scaffold was established by applying xanthate chemistry to enamides. This original β-C(sp2)–H alkylation is regioselective and exhibits broad substrate scope and good functional group tolerance. The large availability of xanthates is advantageous to the scope of the reaction which combines a radical process and a polar reaction.
Synthesis of 3-Arylpiperidines by a Radical 1,4-Aryl Migration
作者:Alexandru Gheorghe、Béatrice Quiclet-Sire、Xavier Vila、Samir Z. Zard
DOI:10.1021/ol0503642
日期:2005.4.14
[reaction: see text] A route to 3-arylpiperidines, 3-arylpyridines, and 5-arylpiperidin-2-ones involving a radical 1,4-aryl migration has been explored. The sequence requires a xanthate addition to an N-allylarylsulfonamide, followed by acetylation and treatment with dilauroyl peroxide to give the 1,4-aryl transfer product, which upon acidic hydrolysis affords the desired piperidine derivative.
Tri- and Tetrasubstituted Functionalized Vinyl Sulfides by Radical Allylation
作者:Laurent Debien、Marie-Gabrielle Braun、Béatrice Quiclet-Sire、Samir Z. Zard
DOI:10.1021/ol403103u
日期:2013.12.20
2-Fluoropyridinyl-6-oxy- precursors derived from phenyl vinyl sulfide react with radicals generated from xanthates via an addition–elimination process to furnish the corresponding vinyl sulfides in good yields. This convergent method is operationally simple and enables a straightforward synthesis of the difficult to access tetrasubstituted vinyl sulfides. Vinyl sulfides were used as more robust enol ether surrogates
A Convergent Radical Based Route to Trifluoromethyl Ketones and to α,β-Unsaturated Trifluoromethyl Ketones
作者:Lucile Anthore、Samir Z. Zard
DOI:10.1021/acs.orglett.5b01344
日期:2015.6.19
A convergent synthesis of trifluoromethyl ketones and α,β-unsaturated trifluoromethyl ketones is described, starting with aliphatic iodides and dithiocarbonates (xanthates) and exploiting both the α- and β-fragmentations of a sulfonyl radical. The transformation initially furnishes the ketones in a masked enol carbonate form, from which they can be easily regenerated.
A Highly Stereoselective, Modular Route to (<i>E</i>)-Vinylsulfones and to (<i>Z</i>)- and (<i>E</i>)-Alkenes
作者:Marie-Gabrielle Braun、Béatrice Quiclet-Sire、Samir Z. Zard
DOI:10.1021/ja207944c
日期:2011.10.12
A recently discovered radical fragmentation of 2-fluoro-6-pyridinoxy derivatives allows a new highlystereoselective and convergent route to (E)-vinylsulfones from allylic alcohols. Reductive desulfonylation or nickel-catalyzed couplings furnish di- and trisubstituted (E)- and (Z)-alkenes.