Nucleophilic Substitutions of Alcohols in High Levels of Catalytic Efficiency
作者:Tanja Stach、Julia Dräger、Peter H. Huy
DOI:10.1021/acs.orglett.8b01023
日期:2018.5.18
A practical method for the nucleophilicsubstitution (SN) of alcohols furnishing alkyl chlorides, bromides, and iodides under stereochemical inversion in high catalytic efficacy is introduced. The fusion of diethylcyclopropenone as a simple Lewis base organocatalyst and benzoyl chloride as a reagent allows notable turnover numbers up to 100. Moreover, the use of plain acetyl chloride as a stoichiometric
Esterification of Tertiary Amides by Alcohols Through C−N Bond Cleavage over CeO
<sub>2</sub>
作者:Takashi Toyao、Md. Nurnobi Rashed、Yoshitsugu Morita、Takashi Kamachi、S. M. A. Hakim Siddiki、Md. A. Ali、A. S. Touchy、Kenichi Kon、Zen Maeno、Kazunari Yoshizawa、Ken‐ichi Shimizu
DOI:10.1002/cctc.201801098
日期:2019.1.9
process proceeds through rate limiting addition of a CeO2 lattice oxygen to the carbonyl group of the adsorbed acetamide species with energy barrier of 17.0 kcal/mol. This value matches well with experimental value (17.9 kcal/mol) obtained from analysis of the Arrhenius plot. Further studies by in situ FT‐IR and temperatureprogrammeddesorption using probe molecules demonstrate that both acidic and
reaction driven by visible light and catalyzed by eosin Y which affords alkyl benzoates from arene diazoniumsalts, carbon monoxide, and alcohols under mild conditions. Tertiary esters can also be prepared in high yields. DFT calculations and radical trapping experiments support a catalyticphotoredox pathway without the requirement for sacrificial redox partners.
Formamides as Lewis Base Catalysts in S<sub>N</sub>Reactions-Efficient Transformation of Alcohols into Chlorides, Amines, and Ethers
作者:Peter H. Huy、Sebastian Motsch、Sarah M. Kappler
DOI:10.1002/anie.201604921
日期:2016.8.16
and waste‐balance (E‐factor down to 2). Chiral substrates are converted with excellent levels of stereochemical inversion (99 %→≥95 % ee). In a practical one‐pot procedure, the primary formed chlorides can be further transformed into amines, azides, ethers, sulfides, and nitriles. The value of the method was demonstrated in straightforward syntheses of the drugs rac‐Clopidogrel and S‐Fendiline.
A General Catalytic Method for Highly Cost‐ and Atom‐Efficient Nucleophilic Substitutions
作者:Peter H. Huy、Isabel Filbrich
DOI:10.1002/chem.201800588
日期:2018.5.23
A general formamide‐catalyzed protocol for the efficient transformation of alcohols into alkyl chlorides, which is promoted by substoichiometric amounts (down to 34 mol %) of inexpensive trichlorotriazine (TCT), is introduced. This is the first example of a TCT‐mediated dihydroxychlorination of an OH‐containing substrate (e.g., alcohols and carboxylic acids) in which all three chlorine atoms of TCT