<scp>Copper‐Catalyzed</scp> Highly Stereoselective Hydrodifluoroallylation of Cyclopropenes and Alkenyl Boronates with 3,<scp>3‐Difluoroallyl</scp> Sulfonium Salts<sup>†</sup>
作者:Xing Gao、Xiaoxiao Ren、Wei Deng、Xingang Zhang
DOI:10.1002/cjoc.202300436
日期:2023.12.15
asymmetric fluoroalkylation with ubiquitous alkenes. The advantages of this protocol are synthetic convenience, high functional group tolerance, and the synthetic versatility of the resulting gem-difluoroallyl cyclopropanes and borylalkanes. The synthetic utility of this approach has also been demonstrated by the diversified transformations of the gem-difluoroallylated products and the rapid synthesis of bioactive
Gem-difluoroallylation of aldehydes and ketones as a convenient route to .alpha.,.alpha.-difluorohomoallylic alcohols
作者:Zhen Yu Yang、Donald J. Burton
DOI:10.1021/jo00003a025
日期:1991.2
In the presence of zinc, 3-bromo-3,3-difluoropropene or 3-iodo-1,1-difluoropropene reacted with carbonyl compounds to give the corresponding alpha,alpha-difluorohomoallylic alcohols in good yields at 0-degrees-C to room temperature. The reaction is applicable to aliphatic and aromatic aldehydes, dialkyl ketones, and alkyl aryl ketones. Reaction with alpha,beta-unsaturated aldehydes and ketones yielded 1,2-adducts exclusively. However, the reaction could not be extended to esters and acyl chlorides. Other metals such as cadmium and tin could also be used to mediate gem-difluoroallylation. The regiochemistry of this reaction could be rationalized in terms of the more nucleophilic alpha-carbon of the gem-difluoroallyl intermediate.
Copper-free defluorinative alkylation of allylic difluorides through Lewis acid-mediated C–F bond activation
The reactions of difluorohomoallyl alcohols with trialkylaluminiums smoothly proceeded in CH2Cl2 at room temperature to give (Z)-fluoro-olefin products in excellent yields. On the basis of this chemistry, fluoro-olefinic dipeptide isostere of norvalinyl glycine was synthesized in stereoselective manner. (C) 2011 Elsevier Ltd. All rights reserved.
Synthesis of (Z)-fluoroallyl azides through aluminium-mediated defluorinative functionalization reactions
The reaction of difluorohomoallyl alcohols with Me2AlCl in CH2Cl2 selectively gave (Z)-fluoroallyl chlorides via S(N)2' type defluorinative chlorination. These chlorides were easily converted to the corresponding (Z)-fluoroallyl azides by the sequential nucleophilic azidation reaction using NaN3. Direct defluorinative azidation of the difluorohomoallyl alcohols was also achieved by treating with Me3SiN3 in the presence of Al(Oi-Pr)(3). Fluoroallyl azides thus obtained successfully applied to the Huisgen. 1,3-dipolar cycloaddition chemistry. (C) 2014 Elsevier Ltd. All rights reserved.
Monofluorinated di- and tetrahydropyrans via Prins-type cyclisations
作者:Adrian P. Dobbs、Levan Pivnevi、Mark J. Penny、S?sa Martinovi?、James N. Iley、Peter T. Stephenson
DOI:10.1039/b606121d
日期:——
The synthesis of a range of fluorinated heterocycles is described via a Lewis acid-mediated Prins-type cyclisation.