Regioselective Sulfonylation/Acylation of Carbohydrates Catalyzed by FeCl<sub>3</sub> Combined with Benzoyltrifluoroacetone and Its Mechanism Study
作者:Jian Lv、Jia-Jia Zhu、Yu Liu、Hai Dong
DOI:10.1021/acs.joc.9b03128
日期:2020.3.6
A catalyticamount of FeCl3 combined with benzoyl trifluoroacetone (Hbtfa) (FeCl3/Hbtfa = 1/2) was used to catalyze sulfonylation/acylation of diols and polyols using diisopropylethylamine (DIPEA) or potassium carbonate (K2CO3) as a base. The catalytic system exhibited high catalytic activity, leading to excellent isolated yields of sulfonylation/acylation products with high regioselectivities. Mechanism
An inexpensive catalyst, Fe(acac)<sub>3</sub>, for regio/site-selective acylation of diols and carbohydrates containing a 1,2-<i>cis</i>-diol
作者:Jian Lv、Jian-Tao Ge、Tao Luo、Hai Dong
DOI:10.1039/c8gc00428e
日期:——
This work describes the [Fe(acac)3] (acac = acetylacetonate)-catalyzed, regio/site-selective acylation of 1,2- and 1,3-diols and glycosides containing a cis-vicinal diol. The iron(III) catalysts initially formed cyclic dioxolane-type intermediates with substrates between the iron(III) species and vicinal diols, and the efficient and selective acylation of one hydroxyl group was subsequently achieved
The 1,5‐diazabicyclo[4.3.0]non‐5‐ene (DBN)‐catalyzed, highly efficient and relatively green regioselective acylation of carbohydrates and diols is firstly developed. The hydroxyl groups can be selectively acylated by the corresponding anhydride in EtOAc in the presence of a catalyticamount (as low as 0.1 equiv.) of DBN at room temperature to 40 °C.
Effective Organotin-Mediated Regioselective Functionalization of Unprotected Carbohydrates
作者:Yixuan Zhou、Kuo-Shiang Liao、Tzu-Yin Chen、Yves S. Y. Hsieh、Chi-Huey Wong
DOI:10.1021/acs.joc.3c00397
日期:2023.6.2
carbohydrates. The counteranion of tetrabutylammonium ion with a weak coordination ability plays a crucial role in the improved regioselective reactions. A convenient access to the intermediates of synthetic value is also demonstrated in the organotin-mediated regioselective tosylation of unprotected carbohydrates, followed by the nucleophilic inversion reaction to give sulfur-containing and azide-modified