Mono and difluorination of centers α to sulfonates and phosphonates using AcOF
作者:Inna Vints、Julia Gatenyo、Shlomo Rozen
DOI:10.1016/j.jfluchem.2013.01.003
日期:2013.2
Acetyl hypofluorite, made easily from diluted fluorine and AcONa is very efficient in fluorinating anionic centers. Compounds containing the moieties -CH2SO2- or -COCH2PO- react with bases to create the corresponding anions which can react with AcOF to produce derivatives containing either the -CHFSO2-or -COCHFPO- groups. Larger excess of base and AcOF result in the difluoro compounds containing the -CF2SO2- or -COCF2PO- sub-structures. The fluorinations proceed fast and smoothly and usually with very good yield even when the base is dissolved in aqueous solution as is the case with K2CO3 or NaHCO3. (C) 2013 Elsevier B.V. All rights reserved.
Organocatalytic alkynylation of densely functionalized monofluorinated derivatives: C(sp3)–C(sp) coupling
作者:Martin Kamlar、Piotr Putaj、Jan Veselý
DOI:10.1016/j.tetlet.2013.02.023
日期:2013.4
Organocatalytic alkynylation of nucleophilic fluorocarbons using hypervalent iodine compounds under cinchona-based catalysis, namely using O-allyl N-anthracenyl cinchona alkaloid derivative II, is described. The reaction gives the final fluoro-propargyl compounds in good to excellent yields (up to 91%) and with moderate to low enantioselectivity (up to 61% ee). The reaction represents the first example of the use of hypervalent iodine compounds for the construction of fluorinated compounds and opens access to the preparation of biologically attractive compounds such as 1,2,3-triazoles. (c) 2013 Elsevier Ltd. All rights reserved.