Metal free fluoroamination of allylsilanes: A route to 3-fluoropyrrolidines
摘要:
The intramolecular fluoroamination of homoallylic amines activated by a triisopropylsilyl or p-tolyldiisopropylsilyl group was successfully performed in the presence of Selectfluor(R) in acetonitrile leading to anti or syn 3-fluoropyrrolidines. The stereochemical outcome of these fluorocyclizations is dictated by the geometry of the alkene precursor. In comparison with oxygen nucleophile, the use of N-tosyl or N-Boc nucleophiles benefits from superior control over stereoselectivity but suffers from competitive fluorodesilylation. (C) 2012 Elsevier B.V. All rights reserved.
Trifluoromethylation of Allylsilanes under Copper Catalysis
作者:Satoshi Mizuta、Oscar Galicia-López、Keary M. Engle、Stefan Verhoog、Katherine Wheelhouse、Gerasimos Rassias、Véronique Gouverneur
DOI:10.1002/chem.201201707
日期:2012.7.9
Branched allylic CF3 products are accessible by copper‐catalyzed trifluoromethylation of allylsilanes with the Togni reagent I. The silyl group is critical to control the outcome of this reaction because in its absence, a product of addition between the alkene and the Togni reagent is formed preferentially. The reaction is inhibited with 2,2,6,6‐tetramethyl‐1‐piperidinyloxy (TEMPO) and is likely to
Trifluoromethylation of Allylsilanes under Photoredox Catalysis
作者:Satoshi Mizuta、Keary M. Engle、Stefan Verhoog、Oscar Galicia-López、Miriam O’Duill、Maurice Médebielle、Katherine Wheelhouse、Gerasimos Rassias、Amber L. Thompson、Véronique Gouverneur
DOI:10.1021/ol400184t
日期:2013.3.15
A new catalytic method to access allylic secondary CF3 products is described. These reactions use the visible light excited Ru(bpy)(3)Cl-2 center dot 6H(2)O catalyst and the Togni or Umemoto reagent as the CF3 source. The photoredox catalytic manifold delivers enantioenriched allylic trifluoromethylated products not accessible under Cu(I) catalysis.